§ 86.010-18 On-board Diagnostics for engines used in applications greater than 14,000 pounds GVWR.

(a) General. Heavy-duty engines intended for use in a heavy-duty vehicle weighing more than 14,000 pounds GVWR must be equipped with an on-board diagnostic (OBD) system capable of monitoring all emission-related engine systems or components during the life of the engine. The OBD requirements of 40 CFR 1036.110 apply starting in model year 2027. In earlier model years, manufacturers may meet the requirements of this section or the requirements of 40 CFR 1036.110. Note that 40 CFR 1036.150(v) allows for an alternative communication protocol before model year 2027. The OBD system is required to detect all malfunctions specified in paragraphs (g), (h), and (i) of this section even though the OBD system is not required to use a unique monitor to detect each of those malfunctions. (1) When the OBD system detects a malfunction, it must store a pending, a MIL-on, or a previous-MIL-on diagnostic trouble code (DTC) in the onboard computer's memory. A malfunction indicator light (MIL) must also be activated as specified in paragraph (b) of this section. (2) Data link connector. (i) For model years 2010 through 2012, the OBD system must be equipped with a data link connector to provide access to the stored DTCs as specified in paragraph (k)(2) of this section. (ii) For model years 2013 and later, the OBD system must be equipped with a standardized data link connector to provide access to the stored DTCs as specified in paragraph (k)(2) of this section. (3) The OBD system cannot be programmed or otherwise designed to deactivate based on age and/or mileage. This requirement does not alter existing law and enforcement practice regarding a manufacturer's liability for an engine beyond its regulatory useful life, except where an engine has been programmed or otherwise designed so that an OBD system deactivates based on age and/or mileage of the engine. (4) Drive cycle or driving cycle , in the context of this § 86.010-18, means operation that meets any of the conditions of paragraphs (a)(4)(i) through (a)(4)(iv) of this section

ing a manufacturer's liability for an engine beyond its regulatory useful life, except where an engine has been programmed or otherwise designed so that an OBD system deactivates based on age and/or mileage of the engine. (4) Drive cycle or driving cycle , in the context of this § 86.010-18, means operation that meets any of the conditions of paragraphs (a)(4)(i) through (a)(4)(iv) of this section. Further, for OBD monitors that run during engine-off conditions, the period of engine-off time following engine shutoff and up to the next engine start may be considered part of the drive cycle for the conditions of paragraphs (a)(4)(i) and (a)(4)(iv) of this section. For engines/vehicles that employ engine shutoff OBD monitoring strategies that do not require the vehicle operator to restart the engine to continue vehicle operation (e.g., a hybrid bus with engine shutoff at idle), the manufacturer may use an alternative definition for drive cycle (e.g., key-on followed by key-off). Any alternative definition must be based on equivalence to engine startup and engine shutoff signaling the beginning and ending of a single driving event for a conventional vehicle. For engines that are not likely to be routinely operated for long continuous periods of time, a manufacturer may also request approval to use an alternative definition for drive cycle (e.g., solely based on engine start and engine shutoff without regard to four hours of continuous engine-on time). Administrator approval of the alternative definition will be based on manufacturer-submitted data and/or information demonstrating the typical usage, operating habits, and/or driving patterns of these vehicles

may also request approval to use an alternative definition for drive cycle (e.g., solely based on engine start and engine shutoff without regard to four hours of continuous engine-on time). Administrator approval of the alternative definition will be based on manufacturer-submitted data and/or information demonstrating the typical usage, operating habits, and/or driving patterns of these vehicles. (i) Begins with engine start and ends with engine shutoff; (ii) Begins with engine start and ends after four hours of continuous engine-on operation; (iii) Begins at the end of the previous four hours of continuous engine-on operation and ends after four hours of continuous engine-on operation; or (iv) Begins at the end of the previous four hours of continuous engine-on operation and ends with engine shutoff. (5) As an alternative to demonstrating compliance with the provisions of paragraphs (b) through (l) of this § 86.010-18, a manufacturer may demonstrate how the OBD system they have designed to comply with California OBD requirements for engines used in applications greater than 14,000 pounds also complies with the intent of the provisions of paragraphs (b) through (l) of this section. To make use of this alternative, the manufacturer must demonstrate to the Administrator how the OBD system they intend to certify meets the intent behind all of the requirements of this section, where applicable (e.g., paragraph (h) of this section would not apply for a diesel fueled/CI engine). Furthermore, if making use of this alternative, the manufacturer must comply with the specific certification documentation requirements of paragraph (m)(3) of this section. (6) Temporary provisions to address hardship due to unusual circumstances. (i) After considering the unusual circumstances, the Administrator may permit the manufacturer to introduce into U.S

ply for a diesel fueled/CI engine). Furthermore, if making use of this alternative, the manufacturer must comply with the specific certification documentation requirements of paragraph (m)(3) of this section. (6) Temporary provisions to address hardship due to unusual circumstances. (i) After considering the unusual circumstances, the Administrator may permit the manufacturer to introduce into U.S. commerce engines that do not comply with this § 86.010-18 for a limited time if all the following conditions apply: (A) Unusual circumstances that are clearly outside the manufacturer's control prevent compliance with the requirements of this § 86.010-18. (B) The manufacturer exercised prudent planning and was not able to avoid the violation and has taken all reasonable steps to minimize the extent of the nonconformity. (C) No other allowances are available under the regulations in this chapter to avoid the impending violation. (ii) To apply for an exemption, the manufacturer must send to the Administrator a written request as soon as possible before being in violation. In the request, the manufacturer must show that all the conditions and requirements of paragraph (a)(6)(i) of this section are met. (iii) The request must also include a plan showing how all the applicable requirements will be met as quickly as possible. (iv) The manufacturer shall give the Administrator other relevant information upon request. (v) The Administrator may include additional conditions on an approval granted under the provisions of this paragraph (a)(6), including provisions that may require field repair at the manufacturer's expense to correct the noncompliance. (vi) Engines sold as non-compliant under this temporary hardship provision must display “non-OBD” in the data stream as required under paragraph (k)(4)(ii) of this section. Upon correcting the noncompliance, the data stream value must be updated accordingly. (b) Malfunction indicator light (MIL) and Diagnostic Trouble Codes (DTC)

d repair at the manufacturer's expense to correct the noncompliance. (vi) Engines sold as non-compliant under this temporary hardship provision must display “non-OBD” in the data stream as required under paragraph (k)(4)(ii) of this section. Upon correcting the noncompliance, the data stream value must be updated accordingly. (b) Malfunction indicator light (MIL) and Diagnostic Trouble Codes (DTC). The OBD system must incorporate a malfunction indicator light (MIL) or equivalent and must store specific types of diagnostic trouble codes (DTC). Unless otherwise specified, all provisions of this paragraph (b) apply for 2010 and later model years. (1) MIL specifications. (i) For model years 2013 and later, the MIL must be located on the primary driver's side instrument panel and be of sufficient illumination and location to be readily visible under all lighting conditions. The MIL must be amber (yellow) in color; the use of red for the OBD-related MIL is prohibited. More than one general purpose malfunction indicator light for emission-related problems shall not be used; separate specific purpose warning lights (e.g., brake system, fasten seat belt, oil pressure, etc.) are permitted. When activated, the MIL shall display the International Standards Organization (ISO) engine symbol. (ii) The OBD system must activate the MIL when the ignition is in the key-on/engine-off position before engine cranking to indicate that the MIL is functional. The MIL shall be activated continuously during this functional check for a minimum of 5 seconds. During this MIL key-on functional check, the data stream value (see paragraph (k)(4)(ii) of this section) for MIL status must indicate “commanded off” unless the OBD system has detected a malfunction and has stored a MIL-on DTC. This MIL key-on functional check is not required during vehicle operation in the key-on/engine-off position subsequent to the initial engine cranking of an ignition cycle (e.g., due to an engine stall or other non-commanded engine shutoff)

paragraph (k)(4)(ii) of this section) for MIL status must indicate “commanded off” unless the OBD system has detected a malfunction and has stored a MIL-on DTC. This MIL key-on functional check is not required during vehicle operation in the key-on/engine-off position subsequent to the initial engine cranking of an ignition cycle (e.g., due to an engine stall or other non-commanded engine shutoff). (iii) As an option, the MIL may be used to indicate readiness status (see paragraph (k)(4)(i) of this section) in a standardized format in the key-on/engine-off position. (iv) A manufacturer may also use the MIL to indicate which, if any, DTCs are currently stored (e.g., to “blink” the stored DTCs). Such use must not activate unintentionally during routine driver operation. (v) For model years 2013 and later, the MIL required by this paragraph (b) must not be used in any other way than is specified in this section. (2) MIL activation and DTC storage protocol. (i) Within 10 seconds of detecting a potential malfunction, the OBD system must store a pending DTC that identifies the potential malfunction. (ii) If the potential malfunction is again detected before the end of the next drive cycle during which monitoring occurs (i.e., the potential malfunction has been confirmed as a malfunction), then within 10 seconds of such detection the OBD system must activate the MIL continuously and store a MIL-on DTC (systems using the SAE J1939 standard protocol specified in paragraph (k)(1) of this section may either erase or retain the pending DTC in conjunction with storing the MIL-on DTC). If the potential malfunction is not detected before the end of the next drive cycle during which monitoring occurs (i.e., there is no indication of the malfunction at any time during the drive cycle), the corresponding pending DTC should be erased at the end of the drive cycle

n paragraph (k)(1) of this section may either erase or retain the pending DTC in conjunction with storing the MIL-on DTC). If the potential malfunction is not detected before the end of the next drive cycle during which monitoring occurs (i.e., there is no indication of the malfunction at any time during the drive cycle), the corresponding pending DTC should be erased at the end of the drive cycle. Similarly, if a malfunction is detected for the first time and confirmed on a given drive cycle without need for further evaluation, then within 10 seconds of such detection the OBD system must activate the MIL continuously and store a MIL-on DTC (again, systems using the SAE J1939 standard protocol specified in paragraph (k)(1) of this section may optionally store a pending DTC in conjunction with storing the MIL-on DTC). (iii) A manufacturer may request Administrator approval to employ alternative statistical MIL activation and DTC storage protocols to those specified in paragraphs (b)(2)(i) and (b)(2)(ii) of this section. Approval will depend upon the manufacturer providing data and/or engineering evaluations that demonstrate that the alternative protocols can evaluate system performance and detect malfunctions in a manner that is equally effective and timely. Strategies requiring on average more than six drive cycles for MIL activation will not be accepted. (iv) The OBD system must store a “freeze frame” of the operating conditions (as defined in paragraph (k)(4)(iii) of this section) present upon detecting a malfunction or a potential malfunction. In the event that a pending DTC has matured to a MIL-on DTC, the manufacturer shall either retain the currently stored freeze frame conditions or replace the stored freeze frame with freeze frame conditions regarding the MIL-on DTC. Any freeze frame stored in conjunction with any pending DTC or MIL-on DTC should be erased upon erasure of the corresponding DTC

alfunction or a potential malfunction. In the event that a pending DTC has matured to a MIL-on DTC, the manufacturer shall either retain the currently stored freeze frame conditions or replace the stored freeze frame with freeze frame conditions regarding the MIL-on DTC. Any freeze frame stored in conjunction with any pending DTC or MIL-on DTC should be erased upon erasure of the corresponding DTC. (v) If the engine enters a limp-home mode of operation that can affect emissions or the performance of the OBD system, or in the event of a malfunction of an onboard computer(s) itself that can affect the performance of the OBD system, the OBD system must activate the MIL and store a MIL-on DTC within 10 seconds to inform the vehicle operator. If the limp-home mode of operation is recoverable (i.e., operation automatically returns to normal at the beginning of the following ignition cycle), the OBD system may wait to activate the MIL and store the MIL-on DTC if the limp-home mode of operation is again entered before the end of the next ignition cycle rather than activating the MIL within 10 seconds on the first drive cycle during which the limp-home mode of operation is entered. (vi) Before the end of an ignition cycle, the OBD system must store a permanent DTC(s) that corresponds to any stored MIL-on DTC(s). (3) MIL deactivation and DTC erasure protocol —(i) Deactivating the MIL. Except as otherwise provided for in paragraphs (g)(2)(iv)(E) and (g)(6)(iv)(B) of this section for diesel misfire malfunctions and empty reductant tanks, and paragraphs (h)(1)(iv)(F), (h)(2)(viii), and (h)(7)(iv)(B) of this section for gasoline fuel system, misfire, and evaporative system malfunctions, once the MIL has been activated, it may be deactivated after three subsequent sequential drive cycles during which the monitoring system responsible for activating the MIL functions and the previously detected malfunction is no longer present and provided no other malfunction has been detected that would independently activate the MIL according

system, misfire, and evaporative system malfunctions, once the MIL has been activated, it may be deactivated after three subsequent sequential drive cycles during which the monitoring system responsible for activating the MIL functions and the previously detected malfunction is no longer present and provided no other malfunction has been detected that would independently activate the MIL according to the requirements outlined in paragraph (b)(2) of this section. (ii) Erasing a MIL-on DTC. The OBD system may erase a MIL-on DTC if the identified malfunction has not again been detected in at least 40 engine warm up cycles and the MIL is presently not activated for that malfunction. The OBD system may also erase a MIL-on DTC upon deactivating the MIL according to paragraph (b)(3)(i) of this section provided a previous-MIL-on DTC is stored upon erasure of the MIL-on DTC. The OBD system may erase a previous-MIL-on DTC if the identified malfunction has not again been detected in at least 40 engine warm up cycles and the MIL is presently not activated for that malfunction. (iii) Erasing a permanent DTC. The OBD system can erase a permanent DTC only if: (A) The OBD system itself determines that the malfunction that caused the corresponding permanent DTC to be stored is no longer present and is not commanding activation of the MIL, concurrent with the requirements of paragraph (b)(3)(i) of this section which, for purposes of this paragraph (b)(3)(iii), shall apply to all monitors

g a permanent DTC. The OBD system can erase a permanent DTC only if: (A) The OBD system itself determines that the malfunction that caused the corresponding permanent DTC to be stored is no longer present and is not commanding activation of the MIL, concurrent with the requirements of paragraph (b)(3)(i) of this section which, for purposes of this paragraph (b)(3)(iii), shall apply to all monitors. (B) All externally erasable DTC information stored in the onboard computer has been erased (i.e., through the use of a scan tool or battery disconnect) and the monitor of the malfunction that caused the permanent DTC to be stored is subject to the minimum ratio requirements of paragraph (d) of this section, the OBD system shall erase the permanent DTC at the end of a drive cycle if the monitor has run and made one or more determinations during a drive cycle that the malfunction of the component or the system is not present and has not made any determinations within the same drive cycle that the malfunction is present. (C)(1) All externally erasable DTC information stored in the onboard computer has been erased (i.e., through the use of a scan tool or battery disconnect) and the monitor of the malfunction that caused the permanent DTC to be stored is not subject to the minimum ratio requirements of paragraph (d) of this section, the OBD system shall erase the permanent DTC at the end of a drive cycle provided the following two criteria have independently been satisfied: (i) The monitor has run and made one or more determinations during a drive cycle that the malfunction is no longer present and has not made any determinations within the same drive cycle that the malfunction is present; and, (ii) The monitor does not detect a malfunction on a drive cycle and the criteria of paragraph (d)(4)(ii) of this section has been met

iteria have independently been satisfied: (i) The monitor has run and made one or more determinations during a drive cycle that the malfunction is no longer present and has not made any determinations within the same drive cycle that the malfunction is present; and, (ii) The monitor does not detect a malfunction on a drive cycle and the criteria of paragraph (d)(4)(ii) of this section has been met. (2) These two separate criteria may be met on the same or different drive cycles provided the monitor never detects a malfunction during either drive cycle, and if criteria (b)(3)(iii)(C)( 1 )( i ) happens first then no malfunction may be detected before criteria (b)(3)(iii)(C)( 1 )( ii ) occurs. If a malfunction occurs after criteria (b)(3)(iii)(C)( 1 )( i ) then criteria (b)(3)(iii)(C)( 1 )( i ) must be satisfied again. For the second criterion, the manufacturer must exclude any temperature and/or elevation provisions of paragraph (d)(4)(ii) of this section. For this paragraph (b)(3)(iii)(C), monitors required to use “similar conditions” as defined in § 86.010-2 to store and erase pending and MIL-on DTCs cannot require that the similar conditions be met prior to erasure of the permanent DTC. (D) The Administrator shall allow monitors subject to paragraph (b)(3)(iii)(B) of this section to use the criteria of paragraph (b)(3)(iii)(C) of this section in lieu of paragraph (b)(3)(iii)(B). Further, manufacturers may request Administrator approval to use alternative criteria to erase the permanent DTC. The Administrator shall approve alternate criteria that will not likely require driving conditions that are longer and more difficult to meet than those required under paragraph (b)(3)(iii)(C) of this section and do not require access to enhanced scan tools to determine conditions necessary to erase the permanent DTC. (4) Exceptions to MIL and DTC requirements

criteria to erase the permanent DTC. The Administrator shall approve alternate criteria that will not likely require driving conditions that are longer and more difficult to meet than those required under paragraph (b)(3)(iii)(C) of this section and do not require access to enhanced scan tools to determine conditions necessary to erase the permanent DTC. (4) Exceptions to MIL and DTC requirements. (i) If a limp-home mode of operation causes a overt indication (e.g., activation of a red engine shut-down warning light) such that the driver is certain to respond and have the problem corrected, a manufacturer may choose not to activate the MIL as required by paragraph (b)(2)(v) of this section. Additionally, if an auxiliary emission control device has been properly activated as approved by the Administrator, a manufacturer may choose not to activate the MIL. (ii) For gasoline engines, a manufacturer may choose to meet the MIL and DTC requirements in § 86.007-17 in lieu of meeting the requirements of paragraph (b) of this § 86.010-18. (c) Monitoring conditions. The OBD system must monitor and detect the malfunctions specified in paragraphs (g), (h), and (i) of this section under the following general monitoring conditions. The more specific monitoring conditions of paragraph (d) of this section are sometimes required according to the provisions of paragraphs (g), (h), and (i) of this section. (1) As specifically provided for in paragraphs (g), (h), and (i) of this section, the monitoring conditions for detecting malfunctions must be technically necessary to ensure robust detection of malfunctions (e.g., avoid false passes and false indications of malfunctions); designed to ensure monitoring will occur under conditions that may reasonably be expected to be encountered in normal vehicle operation and normal vehicle use; and, designed to ensure monitoring will occur during the FTP transient test cycle contained in appendix I paragraph (f), of this part, or similar drive cycle as approved by the Administrator

se passes and false indications of malfunctions); designed to ensure monitoring will occur under conditions that may reasonably be expected to be encountered in normal vehicle operation and normal vehicle use; and, designed to ensure monitoring will occur during the FTP transient test cycle contained in appendix I paragraph (f), of this part, or similar drive cycle as approved by the Administrator. (2) Monitoring must occur at least once per drive cycle in which the monitoring conditions are met. (3) Manufacturers may define monitoring conditions that are not encountered during the FTP cycle as required in paragraph (c)(1) of this section. In doing so, the manufacturer would be expected to consider the degree to which the requirement to run during the FTP transient cycle restricts monitoring during in-use operation, the technical necessity for defining monitoring conditions that are not encountered during the FTP cycle, whether monitoring is otherwise not feasible during the FTP cycle, and/or the ability to demonstrate that the monitoring conditions satisfy the minimum acceptable in-use monitor performance ratio requirement as defined in paragraph (d) of this section. (d) In-use performance tracking. As specifically required in paragraphs (g), (h), and (i) of this section, the OBD system must monitor and detect the malfunctions specified in paragraphs (g), (h), and (i) of this section according to the criteria of this paragraph (d). The OBD system is not required to track and report in-use performance for monitors other than those specifically identified in paragraph (d)(1) of this section, but all monitors on applicable model year engines are still required to meet the in-use performance ratio as specified in paragraph (d)(1)(ii) of this section

), (h), and (i) of this section according to the criteria of this paragraph (d). The OBD system is not required to track and report in-use performance for monitors other than those specifically identified in paragraph (d)(1) of this section, but all monitors on applicable model year engines are still required to meet the in-use performance ratio as specified in paragraph (d)(1)(ii) of this section. (1) The manufacturer must implement software algorithms in the OBD system to individually track and report the in-use performance of the following monitors, if equipped, in the standardized format specified in paragraph (e) of this section: NMHC converting catalyst (paragraph (g)(5) of this section); NO X converting catalyst (paragraph (g)(6) of this section); gasoline catalyst (paragraph (h)(6) of this section); exhaust gas sensor (paragraph (g)(9) of this section) or paragraph (h)(8) of this section); evaporative system (paragraph (h)(7) of this section); EGR system (paragraph (g)(3) of this section or (h)(3) of this section); VVT system (paragraph (g)(10) of this section or (h)(9) of this section); secondary air system (paragraph (h)(5) of this section); DPF system (paragraph (g)(8) of this section); boost pressure control system (paragraph (g)(4) of this section); and, NO X adsorber system (paragraph (g)(7) of this section). (i) The manufacturer shall not use the calculated ratio specified in paragraph (d)(2) of this section or any other indication of monitor frequency as a monitoring condition for a monitor (e.g., using a low ratio to enable more frequent monitoring through diagnostic executive priority or modification of other monitoring conditions, or using a high ratio to enable less frequent monitoring)

section). (i) The manufacturer shall not use the calculated ratio specified in paragraph (d)(2) of this section or any other indication of monitor frequency as a monitoring condition for a monitor (e.g., using a low ratio to enable more frequent monitoring through diagnostic executive priority or modification of other monitoring conditions, or using a high ratio to enable less frequent monitoring). (ii) For model years 2013 and later, manufacturers must define monitoring conditions that, in addition to meeting the criteria in paragraphs (c)(1) and (d)(1) of this section, ensure that the monitor yields an in-use performance ratio (as defined in paragraph (d)(2) of this section) that meets or exceeds the minimum acceptable in-use monitor performance ratio of 0.100 for all monitors specifically required in paragraphs (g), (h), and (i) of this section to meet the monitoring condition requirements of this paragraph (d). (iii) If the most reliable monitoring method developed requires a lower ratio for a specific monitor than that specified in paragraph (d)(1)(ii) of this section, the Administrator may lower the minimum acceptable in-use monitoring performance ratio. (2) In-use performance ratio definition. For monitors required to meet the requirements of paragraph (d) of this section, the performance ratio must be calculated in accordance with the specifications of this paragraph (d)(2). (i) The numerator of the performance ratio is defined as the number of times a vehicle has been operated such that all monitoring conditions have been encountered that are necessary for the specific monitor to detect a malfunction. (ii) The denominator is defined as the number of times a vehicle has been operated in accordance with the provisions of paragraph (d)(4) of this section. (iii) The performance ratio is defined as the numerator divided by the denominator. (3) Specifications for incrementing the numerator

monitoring conditions have been encountered that are necessary for the specific monitor to detect a malfunction. (ii) The denominator is defined as the number of times a vehicle has been operated in accordance with the provisions of paragraph (d)(4) of this section. (iii) The performance ratio is defined as the numerator divided by the denominator. (3) Specifications for incrementing the numerator. (i) Except as provided for in paragraph (d)(3)(v) of this section, the numerator, when incremented, must be incremented by an integer of one. The numerator shall not be incremented more than once per drive cycle. (ii) The numerator for a specific monitor must be incremented within 10 seconds if and only if the following criteria are satisfied on a single drive cycle: (A) Every monitoring condition has been satisfied that is necessary for the specific monitor to detect a malfunction and store a pending DTC, including applicable enable criteria, presence or absence of related DTCs, sufficient length of monitoring time, and diagnostic executive priority assignments (e.g., diagnostic “A” must execute prior to diagnostic “B”). For the purpose of incrementing the numerator, satisfying all the monitoring conditions necessary for a monitor to determine that the monitor is not malfunctioning shall not, by itself, be sufficient to meet this criteria. (B) For monitors that require multiple stages or events in a single drive cycle to detect a malfunction, every monitoring condition necessary for all events to complete must be satisfied. (C) For monitors that require intrusive operation of components to detect a malfunction, a manufacturer must request approval of the strategy used to determine that, had a malfunction been present, the monitor would have detected the malfunction

tiple stages or events in a single drive cycle to detect a malfunction, every monitoring condition necessary for all events to complete must be satisfied. (C) For monitors that require intrusive operation of components to detect a malfunction, a manufacturer must request approval of the strategy used to determine that, had a malfunction been present, the monitor would have detected the malfunction. Administrator approval of the request will be based on the equivalence of the strategy to actual intrusive operation and the ability of the strategy to determine accurately if every monitoring condition was satisfied that was necessary for the intrusive event to occur. (D) For the secondary air system monitor, the criteria in paragraphs (d)(3)(ii)(A) through (d)(3)(ii)(C) of this section are satisfied during normal operation of the secondary air system. Monitoring during intrusive operation of the secondary air system later in the same drive cycle for the sole purpose of monitoring shall not, by itself, be sufficient to meet these criteria. (iii) For monitors that can generate results in a “gray zone” or “non-detection zone” (i.e., monitor results that indicate neither a properly operating system nor a malfunctioning system) or in a “non-decision zone” (e.g., monitors that increment and decrement counters until a pass or fail threshold is reached), the numerator, in general, shall not be incremented when the monitor indicates a result in the “non-detection zone” or prior to the monitor reaching a complete decision

ne” (i.e., monitor results that indicate neither a properly operating system nor a malfunctioning system) or in a “non-decision zone” (e.g., monitors that increment and decrement counters until a pass or fail threshold is reached), the numerator, in general, shall not be incremented when the monitor indicates a result in the “non-detection zone” or prior to the monitor reaching a complete decision. When necessary, the Administrator will consider data and/or engineering analyses submitted by the manufacturer demonstrating the expected frequency of results in the “non-detection zone” and the ability of the monitor to determine accurately, had an actual malfunction been present, whether or not the monitor would have detected a malfunction instead of a result in the “non-detection zone.” (iv) For monitors that run or complete their evaluation with the engine off, the numerator must be incremented either within 10 seconds of the monitor completing its evaluation in the engine off state, or during the first 10 seconds of engine start on the subsequent drive cycle. (v) Manufacturers that use alternative statistical MIL activation protocols as allowed in paragraph (b)(2)(iii) of this section for any of the monitors requiring a numerator, are required to increment the numerator(s) appropriately. The manufacturer may be required to provide supporting data and/or engineering analyses demonstrating both the equivalence of their incrementing approach to the incrementing specified in this paragraph (d)(3) for monitors using the standard MIL activation protocol, and the overall equivalence of the incrementing approach in determining that the minimum acceptable in-use performance ratio of paragraph (d)(1)(ii) of this section, if applicable, has been satisfied. (4) Specifications for incrementing the denominator. (i) The denominator, when incremented, must be incremented by an integer of one. The denominator shall not be incremented more than once per drive cycle

e overall equivalence of the incrementing approach in determining that the minimum acceptable in-use performance ratio of paragraph (d)(1)(ii) of this section, if applicable, has been satisfied. (4) Specifications for incrementing the denominator. (i) The denominator, when incremented, must be incremented by an integer of one. The denominator shall not be incremented more than once per drive cycle. (ii) The denominator for each monitor must be incremented within 10 seconds if and only if the following criteria are satisfied on a single drive cycle: (A) Cumulative time since the start of the drive cycle is greater than or equal to 600 seconds while at an elevation of less than 8,000 feet (2,400 meters) above sea level and at an ambient temperature of greater than or equal to 20 degrees Fahrenheit (−7 C); (B) Cumulative gasoline engine operation at or above 25 miles per hour or diesel engine operation at or above 1,150 rotations per minute (diesel engines may use the gasoline criterion for 2010 through 2012 model years), either of which occurs for greater than or equal to 300 seconds while at an elevation of less than 8,000 feet (2,400 meters) above sea level and at an ambient temperature of greater than or equal to 20 degrees Fahrenheit (−7 C); and, (C) Continuous engine operation at idle (e.g., accelerator pedal released by driver and engine speed less than or equal to 200 rpm above normal warmed-up idle (as determined in the drive position for vehicles equipped with an automatic transmission) or vehicle speed less than or equal to one mile per hour) for greater than or equal to 30 seconds while at an elevation of less than 8,000 feet (2,400 meters) above sea level and at an ambient temperature of greater than or equal to 20 degrees Fahrenheit (−7 C)

or equal to 200 rpm above normal warmed-up idle (as determined in the drive position for vehicles equipped with an automatic transmission) or vehicle speed less than or equal to one mile per hour) for greater than or equal to 30 seconds while at an elevation of less than 8,000 feet (2,400 meters) above sea level and at an ambient temperature of greater than or equal to 20 degrees Fahrenheit (−7 C). (iii) In addition to the requirements of paragraph (d)(4)(ii) of this section, the evaporative system monitor denominator(s) may be incremented if and only if: (A) Cumulative time since the start of the drive cycle is greater than or equal to 600 seconds while at an ambient temperature of greater than or equal to 40 degrees Fahrenheit (4 C) but less than or equal to 95 degrees Fahrenheit (35 C); and, (B) Engine cold start occurs with the engine coolant temperature greater than or equal to 40 degrees Fahrenheit (4 C) but less than or equal to 95 degrees Fahrenheit (35 C) and less than or equal to 12 degrees Fahrenheit (7 C) higher than the ambient temperature. (iv) In addition to the requirements of paragraph (d)(4)(ii) of this section, the denominator(s) for the following monitors may be incremented if and only if the component or strategy is commanded “on” for a cumulative time greater than or equal to 10 seconds. For purposes of determining this commanded “on” time, the OBD system shall not include time during intrusive operation of any of the components or strategies that occurs later in the same drive cycle for the sole purpose of monitoring. (A) Secondary air system (paragraph (h)(5) of this section). (B) Cold start emission reduction strategy (paragraph (h)(4) of this section). (C) Components or systems that operate only at engine start-up (e.g., glow plugs, intake air heaters) and are subject to monitoring under “other emission control systems” (paragraph (i)(4) of this section) or comprehensive component output components (paragraph (i)(3)(iii) of this section)

graph (h)(5) of this section). (B) Cold start emission reduction strategy (paragraph (h)(4) of this section). (C) Components or systems that operate only at engine start-up (e.g., glow plugs, intake air heaters) and are subject to monitoring under “other emission control systems” (paragraph (i)(4) of this section) or comprehensive component output components (paragraph (i)(3)(iii) of this section). (v) In addition to the requirements of paragraph (d)(4)(ii) of this section, the denominator(s) for the following monitors of output components (except those operated only at engine start-up and subject to the requirements of paragraph (d)(4)(iv) of this section, may be incremented if and only if the component is commanded to function (e.g., commanded “on”, “opened”, “closed”, “locked”) on two or more occasions during the drive cycle or for a cumulative time greater than or equal to 10 seconds, whichever occurs first: (A) Variable valve timing and/or control system (paragraph (g)(10) of this section or (h)(9) of this section). (B) “Other emission control systems” (paragraph (i)(4) of this section). (C) Comprehensive component output component (paragraph (i)(3) of this section) (e.g., turbocharger waste-gates, variable length manifold runners). (vi) For monitors of the following components, the manufacturer may use alternative or additional criteria for incrementing the denominator to that set forth in paragraph (d)(4)(ii) of this section. To do so, the alternative criteria must be based on equivalence to the criteria of paragraph (d)(4)(ii) of this section in measuring the frequency of monitor operation relative to the amount of engine operation: (A) Engine cooling system input components (paragraph (i)(1) of this section). (B) “Other emission control systems” (paragraph (i)(4) of this section). (C) Comprehensive component input components that require extended monitoring evaluation (paragraph (i)(3) of this section) (e.g., stuck fuel level sensor rationality)

g the frequency of monitor operation relative to the amount of engine operation: (A) Engine cooling system input components (paragraph (i)(1) of this section). (B) “Other emission control systems” (paragraph (i)(4) of this section). (C) Comprehensive component input components that require extended monitoring evaluation (paragraph (i)(3) of this section) (e.g., stuck fuel level sensor rationality). (D) Comprehensive component input component temperature sensor rationality monitors (paragraph (i)(3) of this section) (e.g., intake air temperature sensor, ambient temperature sensor, fuel temperature sensor). (E) Diesel particulate filter (DPF) frequent regeneration (paragraph (g)(8)(ii)(B) of this section). (vii) For monitors of the following components or other emission controls that experience infrequent regeneration events, the manufacturer may use alternative or additional criteria for incrementing the denominator to that set forth in paragraph (d)(4)(ii) of this section. To do so, the alternative criteria must be based on equivalence to the criteria of paragraph (d)(4)(ii) of this section in measuring the frequency of monitor operation relative to the amount of engine operation: (A) NMHC converting catalyst (paragraph (g)(5) of this section). (B) Diesel particulate filter (DPF) (paragraphs (g)(8)(ii)(A) and (g)(8)(ii)(D) of this section). (viii) In addition to the requirements of paragraph (d)(4)(ii) of this section, the denominator(s) for the following monitors shall be incremented if and only if a regeneration event is commanded for a time greater than or equal to 10 seconds: (A) DPF incomplete regeneration (paragraph (g)(8)(ii)(C) of this section). (B) DPF active/intrusive injection (paragraph (g)(8)(ii)(E) of this section)

on). (viii) In addition to the requirements of paragraph (d)(4)(ii) of this section, the denominator(s) for the following monitors shall be incremented if and only if a regeneration event is commanded for a time greater than or equal to 10 seconds: (A) DPF incomplete regeneration (paragraph (g)(8)(ii)(C) of this section). (B) DPF active/intrusive injection (paragraph (g)(8)(ii)(E) of this section). (ix) For hybrids that employ alternative engine start hardware or strategies (e.g., integrated starter and generators), or alternative fuel vehicles (e.g., dedicated, bi-fuel, or dual-fuel applications), the manufacturer may use alternative criteria for incrementing the denominator to that set forth in paragraph (d)(4)(ii) of this section. In general, the Administrator will not approve alternative criteria for those hybrids that employ engine shut off only at or near idle and/or vehicle stop conditions. To use alternative criteria, the alternative criteria must be based on the equivalence to the criteria of paragraph (d)(4)(ii) of this section in measuring the amount of vehicle operation relative to the measure of conventional vehicle operation. (5) Disablement of numerators and denominators. (i) Within 10 seconds of detecting a malfunction (i.e., a pending or a MIL-on DTC has been stored) that disables a monitor for which the monitoring conditions in paragraph (d) of this section must be met, the OBD system must stop incrementing the numerator and denominator for any monitor that may be disabled as a consequence of the detected malfunction. Within 10 seconds of the time at which the malfunction is no longer being detected (e.g., the pending DTC is erased through OBD system self-clearing or through a scan tool command), incrementing of all applicable numerators and denominators must resume

OBD system must stop incrementing the numerator and denominator for any monitor that may be disabled as a consequence of the detected malfunction. Within 10 seconds of the time at which the malfunction is no longer being detected (e.g., the pending DTC is erased through OBD system self-clearing or through a scan tool command), incrementing of all applicable numerators and denominators must resume. (ii) Within 10 seconds of the start of a power take-off unit (e.g., dump bed, snow plow blade, or aerial bucket, etc.) that disables a monitor for which the monitoring conditions in paragraph (d) of this section must be met, the OBD system must stop incrementing the numerator and denominator for any monitor that may be disabled as a consequence of power take-off operation. Within 10 seconds of the time at which the power take-off operation ends, incrementing of all applicable numerators and denominators must resume. (iii) Within 10 seconds of detecting a malfunction (i.e., a pending or a MIL-on DTC has been stored) of any component used to determine if the criteria of paragraphs (d)(4)(ii) and (d)(4)(iii) of this section are satisfied, the OBD system must stop incrementing all applicable numerators and denominators. Within 10 seconds of the time at which the malfunction is no longer being detected (e.g., the pending DTC is erased through OBD system self-clearing or through a scan tool command), incrementing of all applicable numerators and denominators must resume. (e) Standardized tracking and reporting of in-use monitor performance —(1) General. For monitors required to track and report in-use monitor performance according to paragraph (d) of this section, the performance data must be tracked and reported in accordance with the specifications in paragraphs (d)(2), (e), and (k)(5) of this section

ng of all applicable numerators and denominators must resume. (e) Standardized tracking and reporting of in-use monitor performance —(1) General. For monitors required to track and report in-use monitor performance according to paragraph (d) of this section, the performance data must be tracked and reported in accordance with the specifications in paragraphs (d)(2), (e), and (k)(5) of this section. The OBD system must separately report an in-use monitor performance numerator and denominator for each of the following components: (i) For diesel engines, NMHC catalyst bank 1, NMHC catalyst bank 2, NO X catalyst bank 1, NO X catalyst bank 2, exhaust gas sensor bank 1, exhaust gas sensor bank 2, EGR/VVT system, DPF, boost pressure control system, and NO X adsorber. The OBD system must also report a general denominator and an ignition cycle counter in the standardized format specified in paragraphs (e)(5), (e)(6), and (k)(5) of this section. (ii) For gasoline engines, catalyst bank 1, catalyst bank 2, exhaust gas sensor bank 1, exhaust gas sensor bank 2, evaporative leak detection system, EGR/VVT system, and secondary air system. The OBD system must also report a general denominator and an ignition cycle counter in the standardized format specified in paragraphs (e)(5), (e)(6), and (k)(5) of this section. (iii) For specific components or systems that have multiple monitors that are required to be reported under paragraphs (g) and (h) of this section (e.g., exhaust gas sensor bank 1 may have multiple monitors for sensor response or other sensor characteristics), the OBD system must separately track numerators and denominators for each of the specific monitors and report only the corresponding numerator and denominator for the specific monitor that has the lowest numerical ratio. If two or more specific monitors have identical ratios, the corresponding numerator and denominator for the specific monitor that has the highest denominator must be reported for the specific component. (2) Numerator

numerators and denominators for each of the specific monitors and report only the corresponding numerator and denominator for the specific monitor that has the lowest numerical ratio. If two or more specific monitors have identical ratios, the corresponding numerator and denominator for the specific monitor that has the highest denominator must be reported for the specific component. (2) Numerator. (i) The OBD system must report a separate numerator for each of the applicable components listed in paragraph (e)(1) of this section. (ii) The numerator(s) must be reported in accordance with the specifications in paragraph (k)(5)(ii) of this section. (3) Denominator. (i) The OBD system must report a separate denominator for each of the applicable components listed in paragraph (e)(1) of this section. (ii) The denominator(s) must be reported in accordance with the specifications in paragraph (k)(5)(ii) of this section. (4) Monitor performance ratio. For purposes of determining which corresponding numerator and denominator to report as required in paragraph (e)(1)(iii) of this section, the ratio must be calculated in accordance with the specifications in paragraph (k)(5)(iii) of this section. (5) Ignition cycle counter. (i) The ignition cycle counter is defined as a counter that indicates the number of ignition cycles a vehicle has experienced according to the specifications of paragraph (e)(5)(ii)(B) of this section. The ignition cycle counter must be reported in accordance with the specifications in paragraph (k)(5)(ii) of this section. (ii) The ignition cycle counter must be incremented as follows: (A) The ignition cycle counter, when incremented, must be incremented by an integer of one. The ignition cycle counter shall not be incremented more than once per ignition cycle

raph (e)(5)(ii)(B) of this section. The ignition cycle counter must be reported in accordance with the specifications in paragraph (k)(5)(ii) of this section. (ii) The ignition cycle counter must be incremented as follows: (A) The ignition cycle counter, when incremented, must be incremented by an integer of one. The ignition cycle counter shall not be incremented more than once per ignition cycle. (B) The ignition cycle counter must be incremented within 10 seconds if and only if the engine exceeds an engine speed of 50 to 150 rpm below the normal, warmed-up idle speed (as determined in the drive position for engines paired with an automatic transmission) for at least two seconds plus or minus one second. (iii) Within 10 seconds of detecting a malfunction (i.e., a pending or a MIL-on DTC has been stored) of any component used to determine if the criteria in paragraph (e)(5)(ii)(B) of this section are satisfied (i.e., engine speed or time of operation), the OBD system must stop incrementing the ignition cycle counter. Incrementing of the ignition cycle counter shall not be stopped for any other condition. Within 10 seconds of the time at which the malfunction is no longer being detected (e.g., the pending DTC is erased through OBD system self-clearing or through a scan tool command), incrementing of the ignition cycle counter must resume. (6) General denominator. (i) The general denominator is defined as a measure of the number of times an engine has been operated according to the specifications of paragraph (e)(6)(ii)(B) of this section. The general denominator must be reported in accordance with the specifications in paragraph (k)(5)(ii) of this section. (ii) The general denominator must be incremented as follows: (A) The general denominator, when incremented, must be incremented by an integer of one. The general denominator shall not be incremented more than once per drive cycle

ations of paragraph (e)(6)(ii)(B) of this section. The general denominator must be reported in accordance with the specifications in paragraph (k)(5)(ii) of this section. (ii) The general denominator must be incremented as follows: (A) The general denominator, when incremented, must be incremented by an integer of one. The general denominator shall not be incremented more than once per drive cycle. (B) The general denominator must be incremented within 10 seconds if and only if the criteria identified in paragraph (d)(4)(ii) of this section are satisfied on a single drive cycle. (C) Within 10 seconds of detecting a malfunction (i.e., a pending or a MIL-on DTC has been stored) of any component used to determine if the criteria in paragraph (d)(4)(ii) of this section are satisfied (i.e., vehicle speed/load, ambient temperature, elevation, idle operation, or time of operation), the OBD system must stop incrementing the general denominator. Incrementing of the general denominator shall not be stopped for any other condition (e.g., the disablement criteria in paragraphs (d)(5)(i) and (d)(5)(ii) of this section shall not disable the general denominator). Within 10 seconds of the time at which the malfunction is no longer being detected (e.g., the pending DTC is erased through OBD system self-clearing or through a scan tool command), incrementing of the general denominator must resume. (f) Malfunction criteria determination. (1) In determining the malfunction criteria for the diesel engine monitors required under paragraphs (g) and (i) of this section that are required to indicate a malfunction before emissions exceed an emission threshold based on any applicable standard, the manufacturer must: (i) Use the emission test cycle and standard (i.e., the transient FTP or the supplemental emissions test (SET)) determined by the manufacturer to provide the most effective monitoring conditions and robust monitor provided all other applicable requirements of this section are met

te a malfunction before emissions exceed an emission threshold based on any applicable standard, the manufacturer must: (i) Use the emission test cycle and standard (i.e., the transient FTP or the supplemental emissions test (SET)) determined by the manufacturer to provide the most effective monitoring conditions and robust monitor provided all other applicable requirements of this section are met. (ii) Identify in the certification documentation required under paragraph (m) of this section, the test cycle and standard determined by the manufacturer to be the most stringent for each applicable monitor and the most effective and robust for each applicable monitor. (iii) If the Administrator reasonably believes that a manufacturer has determined incorrectly the test cycle and standard that is most stringent or effective, the manufacturer must be able to provide emission data and/or engineering analysis supporting their choice of test cycle and standard. (2) On engines equipped with emission controls that experience infrequent regeneration events, a manufacturer need not adjust the emission test results that are used to determine the malfunction criteria for monitors that are required to indicate a malfunction before emissions exceed a certain emission threshold. For each such monitor, should the manufacturer choose to adjust the emission test results, the manufacturer must adjust the emission result as done in accordance with the provisions of § 86.004-28(i) with the component for which the malfunction criteria are being established having been deteriorated to the malfunction threshold. The adjusted emission value must be used for purposes of determining whether or not the applicable emission threshold is exceeded. (i) For purposes of this paragraph (f)(2), regeneration means an event, by design, during which emissions levels change while the emission control performance is being restored

nction criteria are being established having been deteriorated to the malfunction threshold. The adjusted emission value must be used for purposes of determining whether or not the applicable emission threshold is exceeded. (i) For purposes of this paragraph (f)(2), regeneration means an event, by design, during which emissions levels change while the emission control performance is being restored. (ii) For purposes of this paragraph (f)(2), infrequent means having an expected frequency of less than once per transient FTP cycle. (3) For gasoline engines, rather than meeting the malfunction criteria specified under paragraphs (h) and (i) of this section, the manufacturer may request approval to use an OBD system certified to the requirements of § 86.007-17. To do so, the manufacturer must demonstrate use of good engineering judgment in determining equivalent malfunction detection criteria to those required in this section. (g) OBD monitoring requirements for diesel-fueled/compression-ignition engines. The following table shows the thresholds at which point certain components or systems, as specified in this paragraph (g), are considered malfunctioning. Table 1—OBD Emissions Thresholds for Diesel-Fueled/Compression-Ignition Engines Meant for Placement in Applications Greater Than 14,000 Pounds GVWR (g/bhp-hr) Component § 86.010-18 reference NMHC CO NO X PM Model years 2010-2012: NO X aftertreatment system (g)(6) (g)(7) + 0.6 Diesel particulate filter (DPF) system (g)(8) 2.5x 0.05/ + 0.04 Air-fuel ratio sensors upstream of aftertreatment devices (g)(9) 2.5x 2.5x + 0.3 0.03/ + 0.02 Air-fuel ratio sensors downstream of aftertreatment devices (g)(9) 2.5x + 0.3 0.05/ + 0.04 NO X sensors (g)(9) + 0.6 0.05/ + 0.04 “Other monitors” with emissions thresholds (g)(1) (g)(3) (g)(4) (g)(10) 2.5x 2.5x + 0.3 0.03/ + 0.02 Model years 2013 and later: NO X aftertreatment system (g)(6) (g)(7) + 0.3 Diesel particulate filter (DPF) system (g)(8) 2x 0.05/ + 0.04 Air-fuel ratio sensors upstream of aftertreatment devices (g)(9) 2x 2x + 0.

reatment devices (g)(9) 2.5x + 0.3 0.05/ + 0.04 NO X sensors (g)(9) + 0.6 0.05/ + 0.04 “Other monitors” with emissions thresholds (g)(1) (g)(3) (g)(4) (g)(10) 2.5x 2.5x + 0.3 0.03/ + 0.02 Model years 2013 and later: NO X aftertreatment system (g)(6) (g)(7) + 0.3 Diesel particulate filter (DPF) system (g)(8) 2x 0.05/ + 0.04 Air-fuel ratio sensors upstream of aftertreatment devices (g)(9) 2x 2x + 0.3 0.03/ + 0.02 Air-fuel ratio sensors downstream of aftertreatment devices (g)(9) 2x + 0.3 0.05/ + 0.04 NO X sensors (g)(9) + 0.3 0.05/ + 0.04 “Other monitors” with emissions thresholds (g)(1) (g)(2) (g)(3) (g)(4) (g)(10) 2x 2x + 0.3 0.03/ + 0.02 Notes: FEL = Family Emissions Limit; 2.5x std means a multiple of 2.5 times the applicable emissions standard; + 0.3 means the standard or FEL plus 0.3; 0.05/ + 0.04 means an absolute level of 0.05 or an additive level of the standard or FEL plus 0.04, whichever level is higher; these emissions thresholds apply to the monitoring requirements of paragraph (g) of this § 86.010-18. (1) Fuel system monitoring —(i) General. The OBD system must monitor the fuel delivery system to verify that it is functioning properly. The individual electronic components (e.g., actuators, valves, sensors, pumps) that are used in the fuel system and are not specifically addressed in this paragraph (g)(1) must be monitored in accordance with the requirements of paragraph (i)(3) of this section. (ii) Fuel system malfunction criteria —(A) Fuel system pressure control. The OBD system must monitor the fuel system's ability to control to the desired fuel pressure. This monitoring must be done continuously unless new hardware has to be added, in which case the monitoring must be done at least once per drive cycle. The OBD system must detect a malfunction of the fuel system's pressure control system when the pressure control system is unable to maintain an engine's emissions at or below the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g)

g must be done continuously unless new hardware has to be added, in which case the monitoring must be done at least once per drive cycle. The OBD system must detect a malfunction of the fuel system's pressure control system when the pressure control system is unable to maintain an engine's emissions at or below the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the fuel system pressure control could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that the commanded fuel system pressure cannot be delivered. For model year 2010 to 2012 engines with a unit injector fuel system, this requirement may be met by conducting a functional check of the fuel system pressure control in lieu of monitoring for conditions that could cause an engine's emissions to exceed the applicable emissions thresholds. (B) Fuel system injection quantity. The OBD system must detect a malfunction of the fuel injection system when the system is unable to deliver the commanded quantity of fuel necessary to maintain an engine's emissions at or below the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the fuel injection quantity could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that the commanded fuel quantity cannot be delivered. For model year 2010 to 2012 engines with a unit injector fuel system, this requirement may be met by conducting a functional check of the fuel system injection quantity in lieu of monitoring for conditions that could cause an engine's emissions to exceed the applicable emissions thresholds. (C) Fuel system injection timing

s control limits such that the commanded fuel quantity cannot be delivered. For model year 2010 to 2012 engines with a unit injector fuel system, this requirement may be met by conducting a functional check of the fuel system injection quantity in lieu of monitoring for conditions that could cause an engine's emissions to exceed the applicable emissions thresholds. (C) Fuel system injection timing. The OBD system must detect a malfunction of the fuel injection system when the system is unable to deliver fuel at the proper crank angle/timing (e.g., injection timing too advanced or too retarded) necessary to maintain an engine's emissions at or below the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the fuel injection timing could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that the commanded fuel injection timing cannot be achieved. For model year 2010 to 2012 engines with a unit injector fuel system, this requirement may be met by conducting a functional check of the fuel system injection timing in lieu of monitoring for conditions that could cause an engine's emissions to exceed the applicable emissions thresholds. (D) Combined Monitoring. For engines with a unit injector fuel system, the manufacturer may request Administrator approval to combine the malfunction criteria of paragraphs (g)(1)(ii)(A) through (g)(1)(ii)(C) of this section into one malfunction provided the manufacturer can demonstrate that the combined malfunction will satisfy the intent of each separate malfunction criteria

missions thresholds. (D) Combined Monitoring. For engines with a unit injector fuel system, the manufacturer may request Administrator approval to combine the malfunction criteria of paragraphs (g)(1)(ii)(A) through (g)(1)(ii)(C) of this section into one malfunction provided the manufacturer can demonstrate that the combined malfunction will satisfy the intent of each separate malfunction criteria. For engines with a common rail fuel system, the manufacturer may request Administrator approval to combine the malfunction criteria of paragraphs (g)(1)(ii)(B) through (g)(1)(ii)(C) of this section into one malfunction provided the manufacturer can demonstrate that the combined malfunction will satisfy the intent of each separate malfunction criteria. (E) Fuel system feedback control. See paragraph (i)(6) of this section. (iii) Fuel system monitoring conditions. (A) With the exceptions noted in this paragraph for unit injector systems, the OBD system must monitor continuously for malfunctions identified in paragraphs (g)(1)(ii)(A) and (g)(1)(ii)(E) of this section. For 2010 through 2012 unit injector systems, where functional monitoring is done in lieu of emission threshold monitoring for malfunctions identified in paragraph (g)(1)(ii)(A) of this section, the manufacturer must define the monitoring conditions in accordance with paragraphs (c) and (d) of this section. For 2013 and later unit injector systems, the manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(1)(ii)(A) of this section in accordance with paragraphs (c) and (d) of this section, with the exception that monitoring must occur every time the monitoring conditions are met during the drive cycle rather than once per drive cycle as required in paragraph (c)(2) of this section

it injector systems, the manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(1)(ii)(A) of this section in accordance with paragraphs (c) and (d) of this section, with the exception that monitoring must occur every time the monitoring conditions are met during the drive cycle rather than once per drive cycle as required in paragraph (c)(2) of this section. (B) For 2010 through 2012, the manufacturer must define the monitoring conditions for malfunctions identified in paragraphs (g)(1)(ii)(B), (g)(1)(ii)(C), and (g)(1)(ii)(D) of this section in accordance with paragraphs (c) and (d) of this section. For 2013 and later, the manufacturer must define the monitoring conditions in accordance with paragraphs (c) and (d) of this section, with the exception that monitoring must occur every time the monitoring conditions are met during the drive cycle rather than once per drive cycle as required in paragraph (c)(2) of this section. (iv) Fuel system MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. (2) Engine misfire monitoring —(i) General. The OBD system must monitor the engine for misfire causing excess emissions. (ii) Engine misfire malfunction criteria. (A) The OBD system must be capable of detecting misfire occurring in one or more cylinders. To the extent possible without adding hardware for this specific purpose, the OBD system must also identify the specific misfiring cylinder. If more than one cylinder is misfiring continuously, or if more than one but less than half of the cylinders are misfiring continuously (if the manufacturer can demonstrate the robustness of their monitor to the approval of the Administrator), a separate DTC must be stored indicating that multiple cylinders are misfiring. When identifying multiple cylinder misfire, the OBD system is not required to identify individually through separate DTCs each of the continuously misfiring cylinders

f of the cylinders are misfiring continuously (if the manufacturer can demonstrate the robustness of their monitor to the approval of the Administrator), a separate DTC must be stored indicating that multiple cylinders are misfiring. When identifying multiple cylinder misfire, the OBD system is not required to identify individually through separate DTCs each of the continuously misfiring cylinders. (B) For model years 2013 and later, on engines equipped with sensors that can detect combustion or combustion quality ( e.g. , for use in engines with homogeneous charge compression ignition (HCCI) control systems), the OBD system must detect a misfire malfunction when the percentage of misfire is 5 percent or greater. (iii) Engine misfire monitoring conditions. (A) The OBD system must monitor for engine misfire during engine idle conditions at least once per drive cycle in which the monitoring conditions for misfire are met. The manufacturer must be able to demonstrate via engineering analysis and/or data that the self-defined monitoring conditions: are technically necessary to ensure robust detection of malfunctions (e.g., avoid false passes and false detection of malfunctions); require no more than 1000 cumulative engine revolutions; and, do not require any single continuous idle operation of more than 15 seconds to make a determination that a malfunction is present (e.g., a decision can be made with data gathered during several idle operations of 15 seconds or less); or, satisfy the requirements of paragraph (c) of this section with alternative engine operating conditions. (B) Manufacturers may employ alternative monitoring conditions (e.g., off-idle) provided the manufacturer is able to demonstrate that the alternative monitoring ensure equivalent robust detection of malfunctions and equivalent timeliness in detection of malfunctions

s of 15 seconds or less); or, satisfy the requirements of paragraph (c) of this section with alternative engine operating conditions. (B) Manufacturers may employ alternative monitoring conditions (e.g., off-idle) provided the manufacturer is able to demonstrate that the alternative monitoring ensure equivalent robust detection of malfunctions and equivalent timeliness in detection of malfunctions. (C) For model years 2013 through 2018, on engines equipped with sensors that can detect combustion or combustion quality, the OBD system must monitor continuously for engine misfire when positive torque is between 20 and 75 percent of peak torque, and engine speed is less than 75 percent of maximum engine speed. If a monitoring system cannot detect all misfire patterns under all required engine speed and load conditions, the manufacturer may request that the Administrator approve the monitoring system nonetheless. In evaluating the manufacturer's request, the Administrator will consider the following factors: The magnitude of the region(s) in which misfire detection is limited; the degree to which misfire detection is limited in the region(s) ( i.e. , the probability of detection of misfire events); the frequency with which said region(s) are expected to be encountered in-use; the type of misfire patterns for which misfire detection is troublesome; and demonstration that the monitoring technology employed is not inherently incapable of detecting misfire under required conditions ( i.e. , compliance can be achieved on other engines). The evaluation will be based on the following misfire patterns: Equally spaced misfire occurring on randomly selected cylinders; single cylinder continuous misfire; and, paired cylinder (cylinders firing at the same crank angle) continuous misfire

ng technology employed is not inherently incapable of detecting misfire under required conditions ( i.e. , compliance can be achieved on other engines). The evaluation will be based on the following misfire patterns: Equally spaced misfire occurring on randomly selected cylinders; single cylinder continuous misfire; and, paired cylinder (cylinders firing at the same crank angle) continuous misfire. (D) For 20 percent of 2019 model year, 50 percent of 2020 model, and 100 percent of 2021 and later model year diesel engines (percentage based on the manufacturer's projected sales volume of all diesel engines subject to this regulation) equipped with sensors that can detect combustion or combustion quality, the OBD system must monitor continuously for engine misfire under all positive torque engine speed conditions except within the following range: The engine operating region bound by the positive torque line ( i.e. , engine torque with transmission in neutral) and the two following points: engine speed of 50 percent of maximum engine speed with the engine torque at the positive torque line, and 100 percent of the maximum engine speed with the engine torque at 10 percent of peak torque above the positive torque line. If a monitoring system cannot detect all misfire patterns under all required engine speed and load conditions, the manufacturer may request that the Administrator approve the monitoring system nonetheless. In evaluating the manufacturer's request, the Administrator will consider the following factors: The magnitude of the region(s) in which misfire detection is limited; the degree to which misfire detection is limited in the region(s) ( i.e. , the probability of detection of misfire events); the frequency with which said region(s) are expected to be encountered in-use; the type of misfire patterns for which misfire detection is troublesome; and demonstration that the monitoring technology employed is not inherently incapable of detecting misfire under required conditions ( i.e

which misfire detection is limited in the region(s) ( i.e. , the probability of detection of misfire events); the frequency with which said region(s) are expected to be encountered in-use; the type of misfire patterns for which misfire detection is troublesome; and demonstration that the monitoring technology employed is not inherently incapable of detecting misfire under required conditions ( i.e. , compliance can be achieved on other engines). The evaluation will be based on the following misfire patterns: Equally spaced misfire occurring on randomly selected cylinders; single cylinder continuous misfire; and, paired cylinder (cylinders firing at the same crank angle) continuous misfire. (iv) Engine misfire MIL activation and DTC storage. (A) General requirements for MIL activation and DTC storage are set forth in paragraph (b) of this section. (B) For model years 2013 and later, on engines equipped with sensors that can detect combustion or combustion quality, upon detection of the percentage of misfire specified in paragraph (g)(2)(ii)(B) of this section, the following criteria shall apply for MIL activation and DTC storage: A pending DTC must be stored no later than after the fourth exceedance of the percentage of misfire specified in paragraph (g)(2)(ii) of this section during a single drive cycle; if a pending fault code has been stored, the OBD system must activate the MIL and store a MIL-on DTC within 10 seconds if the percentage of misfire specified in paragraph (g)(2)(ii) of this section is again exceeded four times during the drive cycle immediately following storage of the pending DTC, regardless of the conditions encountered during the drive cycle, or on the next drive cycle in which similar conditions are encountered to those that were occurring when the pending DTC was stored. Similar conditions means an engine speed within 375 rpm, engine load within 20 percent, and the same warm up status (i.e., cold or hot)

the drive cycle immediately following storage of the pending DTC, regardless of the conditions encountered during the drive cycle, or on the next drive cycle in which similar conditions are encountered to those that were occurring when the pending DTC was stored. Similar conditions means an engine speed within 375 rpm, engine load within 20 percent, and the same warm up status (i.e., cold or hot). The Administrator may approve other definitions of similar conditions based on comparable timeliness and reliability in detecting similar engine operation. The pending DTC may be erased at the end of the next drive cycle in which similar conditions are encountered to those that were occurring when the pending DTC was stored provided the specified percentage of misfire was not again exceeded. The pending DTC may also be erased if similar conditions are not encountered during the 80 drive cycles immediately following initial detection of the malfunction. (C) For model years 2013 and later, on engines equipped with sensors that can detect combustion or combustion quality, the OBD system must store and erase freeze frame conditions either in conjunction with storing and erasing a pending DTC or in conjunction with storing and erasing a MIL-on DTC. If freeze frame conditions are stored for a malfunction other than a misfire malfunction when a DTC is stored as specified in paragraph (g)(2)(iv)(B) of this section, the stored freeze frame information must be replaced with the freeze frame information regarding the misfire malfunction. (D) For model years 2013 and later, on engines equipped with sensors that can detect combustion or combustion quality, upon detection of misfire according to paragraph (g)(2)(iv)(B) of this section, the OBD system must also store the following engine conditions: engine speed, load, and warm up status of the first misfire event that resulted in the storage of the pending DTC

he misfire malfunction. (D) For model years 2013 and later, on engines equipped with sensors that can detect combustion or combustion quality, upon detection of misfire according to paragraph (g)(2)(iv)(B) of this section, the OBD system must also store the following engine conditions: engine speed, load, and warm up status of the first misfire event that resulted in the storage of the pending DTC. (E) For model years 2013 and later, on engines equipped with sensors that can detect combustion or combustion quality, the MIL may be deactivated after three sequential drive cycles in which similar conditions have been encountered without an exceedance of the specified percentage of misfire. (3) EGR system monitoring —(i) General. The OBD system must monitor the EGR system on engines so equipped for low flow rate, high flow rate, and slow response malfunctions. For engines equipped with EGR coolers (e.g., heat exchangers), the OBD system must monitor the cooler for insufficient cooling malfunctions. The individual electronic components (e.g., actuators, valves, sensors) that are used in the EGR system must be monitored in accordance with the comprehensive component requirements in paragraph (i)(3) of this section. (ii) EGR system malfunction criteria —(A) EGR low flow. The OBD system must detect a malfunction of the EGR system prior to a decrease from the manufacturer's specified EGR flow rate that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the EGR system that causes a decrease in flow could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that it cannot increase EGR flow to achieve the commanded flow rate. (B) EGR high flow

own in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the EGR system that causes a decrease in flow could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that it cannot increase EGR flow to achieve the commanded flow rate. (B) EGR high flow. The OBD system must detect a malfunction of the EGR system, including a leaking EGR valve (i.e., exhaust gas flowing through the valve when the valve is commanded closed) prior to an increase from the manufacturer's specified EGR flow rate that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the EGR system that causes an increase in flow could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that it cannot reduce EGR flow to achieve the commanded flow rate. (C) EGR slow response. The OBD system must detect a malfunction of the EGR system prior to any failure or deterioration in the capability of the EGR system to achieve the commanded flow rate within a manufacturer-specified time that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). The OBD system must monitor both the capability of the EGR system to respond to a commanded increase in flow and the capability of the EGR system to respond to a commanded decrease in flow. (D) EGR system feedback control. See paragraph (i)(6) of this section. (E) EGR cooler performance

e's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). The OBD system must monitor both the capability of the EGR system to respond to a commanded increase in flow and the capability of the EGR system to respond to a commanded decrease in flow. (D) EGR system feedback control. See paragraph (i)(6) of this section. (E) EGR cooler performance. The OBD system must detect a malfunction of the EGR cooler prior to a reduction from the manufacturer's specified cooling performance that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the EGR cooler could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has no detectable amount of EGR cooling. (iii) EGR system monitoring conditions. (A) The OBD system must monitor continuously for malfunctions identified in paragraphs (g)(3)(ii)(A), (g)(3)(ii)(B), and (g)(3)(ii)(D) of this section. (B) The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(3)(ii)(C) of this section in accordance with paragraphs (c) and (d) of this section, with the exception that monitoring must occur every time the monitoring conditions are met during the drive cycle rather than once per drive cycle as required in paragraph (c)(2) of this section. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraph (g)(3)(ii)(C) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (C) The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(3)(ii)(E) of this section in accordance with paragraphs (c) and (d) of this section

monitors used to detect malfunctions identified in paragraph (g)(3)(ii)(C) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (C) The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(3)(ii)(E) of this section in accordance with paragraphs (c) and (d) of this section. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraph (g)(3)(ii)(E) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (D) The manufacturer may request Administrator approval to disable temporarily the EGR system monitor(s) under specific ambient conditions (e.g., when freezing may affect performance of the system) or during specific operating conditions (e.g., transients, extreme low or high flow conditions). The manufacturer must be able to demonstrate via data or engineering analysis that a reliable system monitor cannot be run when these conditions exist because it cannot robustly distinguish between a malfunctioning system and a properly operating system. The manufacturer is still required to maintain comprehensive component monitoring as required in paragraph (i)(3) of this section. (iv) EGR system MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. (4) Turbo boost control system monitoring —(i) General. The OBD system must monitor the boost pressure control system (e.g., turbocharger) on engines so equipped for under and over boost malfunctions. For engines equipped with variable geometry turbochargers (VGT), the OBD system must monitor the VGT system for slow response malfunctions. For engines equipped with charge air cooler systems, the OBD system must monitor the charge air cooler system for cooling system performance malfunctions

pressure control system (e.g., turbocharger) on engines so equipped for under and over boost malfunctions. For engines equipped with variable geometry turbochargers (VGT), the OBD system must monitor the VGT system for slow response malfunctions. For engines equipped with charge air cooler systems, the OBD system must monitor the charge air cooler system for cooling system performance malfunctions. The individual electronic components (e.g., actuators, valves, sensors) that are used in the boost pressure control system must be monitored in accordance with the comprehensive component requirements in paragraph (i)(3) of this section. (ii) Turbo boost control system malfunction criteria —(A) Turbo underboost. The OBD system must detect a malfunction of the boost pressure control system prior to a decrease from the manufacturer's commanded boost pressure, or expected boost pressure on engines not equipped with a boost pressure control system, that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the boost pressure control system that causes a decrease in boost could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that it cannot increase boost to achieve the commanded boost pressure. (B) Turbo overboost. The OBD system must detect a malfunction of the boost pressure control system on engines so equipped prior to an increase from the manufacturer's commanded boost pressure that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g)

that it cannot increase boost to achieve the commanded boost pressure. (B) Turbo overboost. The OBD system must detect a malfunction of the boost pressure control system on engines so equipped prior to an increase from the manufacturer's commanded boost pressure that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the boost pressure control system that causes an increase in boost could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that it cannot decrease boost to achieve the commanded boost pressure. (C) VGT slow response. The OBD system must detect a malfunction prior to any failure or deterioration in the capability of the VGT system on engines so equipped to achieve the commanded turbocharger geometry within a manufacturer-specified time that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the VGT system response could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction of the VGT system when proper functional response of the system to computer commands does not occur. (D) Turbo boost feedback control. See paragraph (i)(6)of this section. (E) Charge air undercooling. The OBD system must detect a malfunction of the charge air cooling system prior to a decrease from the manufacturer's specified cooling rate that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g)

mmands does not occur. (D) Turbo boost feedback control. See paragraph (i)(6)of this section. (E) Charge air undercooling. The OBD system must detect a malfunction of the charge air cooling system prior to a decrease from the manufacturer's specified cooling rate that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). For engines in which no failure or deterioration of the charge air cooling system that causes a decrease in cooling performance could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has no detectable amount of charge air cooling. (iii) Turbo boost monitoring conditions. (A) The OBD system must monitor continuously for malfunctions identified in paragraphs (g)(4)(ii)(A), (g)(4)(ii)(B), and (g)(4)(ii)(D) of this section. (B) The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(4)(ii)(C) of this section in accordance with paragraphs (c) and (d) of this section, with the exception that monitoring must occur every time the monitoring conditions are met during the drive cycle rather than once per drive cycle as required in paragraph (c)(2) of this section. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraph (g)(4)(ii)(C) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (C) The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(4)(ii)(E) of this section in accordance with paragraphs (c) and (d) of this section

monitors used to detect malfunctions identified in paragraph (g)(4)(ii)(C) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (C) The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(4)(ii)(E) of this section in accordance with paragraphs (c) and (d) of this section. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraph (g)(4)(ii)(E) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (D) The manufacturer may request Administrator approval to disable temporarily the turbo boost system monitor(s) during specific operating conditions (e.g., transients, extreme low or high flow conditions). The manufacturer must be able to demonstrate via data or engineering analysis that a reliable system monitor cannot be run when these conditions exist because it cannot robustly distinguish between a malfunctioning system and a properly operating system. The manufacturer is still required to maintain comprehensive component monitoring as required in paragraph (i)(3) of this section. (iv) Turbo boost system MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. (5) NMHC converting catalyst monitoring —(i) General. The OBD system must monitor the NMHC converting catalyst(s) for proper NMHC conversion capability. For purposes of this paragraph (g)(5), each catalyst that converts NMHC must be monitored either individually or in combination with others. For purposes of this paragraph (g)(5), NMHC conversion that may occur over the DPF or other aftertreatment devices is not included. (ii) NMHC converting catalyst malfunction criteria —(A) NMHC converting catalyst conversion efficiency

C conversion capability. For purposes of this paragraph (g)(5), each catalyst that converts NMHC must be monitored either individually or in combination with others. For purposes of this paragraph (g)(5), NMHC conversion that may occur over the DPF or other aftertreatment devices is not included. (ii) NMHC converting catalyst malfunction criteria —(A) NMHC converting catalyst conversion efficiency. The OBD system must detect a malfunction when the catalyst has no detectable amount of NMHC conversion capability. (B) NMHC converting catalyst aftertreatment assistance functions. For catalysts used to generate an exotherm to assist DPF regeneration, the OBD system must detect a malfunction when the catalyst is unable to generate a sufficient exotherm to achieve DPF regeneration. In meeting this requirement, the OBD system must detect a malfunction when the DOC is unable to generate a temperature rise of 100 degrees C, or to reach the necessary DPF regeneration temperature, within 60 seconds of initiating an active DPF regeneration. Further, the OBD system must detect a malfunction when the DOC is unable to sustain the necessary regeneration temperature for the duration of the regeneration event. The OBD or control system must abort the regeneration if the regeneration temperature has not been reached within five minutes of initiating an active regeneration event, or if the regeneration temperature cannot be sustained for the duration of the regeneration event. As an alternative to these specific malfunction criteria, the manufacturer may employ different criteria. To do so, the manufacturer must submit a description with supporting data, subject to Administrator approval, of their DPF regeneration monitoring strategy. The Administrator will consider the strategy's equivalence to the specific criteria stated in this paragraph when considering the request

As an alternative to these specific malfunction criteria, the manufacturer may employ different criteria. To do so, the manufacturer must submit a description with supporting data, subject to Administrator approval, of their DPF regeneration monitoring strategy. The Administrator will consider the strategy's equivalence to the specific criteria stated in this paragraph when considering the request. Also as an alternative to these specific malfunction criteria, the manufacturer may employ an OBD monitor that detects a catalyst malfunction when the catalyst conversion capability decreases to the point that NMHC emissions exceed 2.5 times the applicable NMHC emission standard but must adjust emission test results pursuant to paragraph (f)(2) of this section. For catalysts located downstream of a DPF and used to convert NMHC emissions during DPF regeneration, the OBD system must detect a malfunction when the catalyst has no detectable amount of NMHC conversion capability unless the manufacturer can demonstrate that deterioration or malfunction of the catalyst will not result in emissions that exceed the applicable NMHC standard. (iii) NMHC converting catalyst monitoring conditions. The manufacturer must define the monitoring conditions for malfunctions identified in paragraphs (g)(5)(ii)(A) and (g)(5)(ii)(B) of this section in accordance with paragraphs (c) and (d) of this section. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraphs (g)(5)(ii)(A) and (g)(5)(ii)(B) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (iv) NMHC converting catalyst MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section

monitors used to detect malfunctions identified in paragraphs (g)(5)(ii)(A) and (g)(5)(ii)(B) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (iv) NMHC converting catalyst MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. The monitoring method for the NMHC converting catalyst(s) must be capable of detecting all instances, except diagnostic self-clearing, when a catalyst DTC has been erased but the catalyst has not been replaced (e.g., catalyst over-temperature histogram approaches are not acceptable). (6) Selective catalytic reduction (SCR) and lean NO X catalyst monitoring —(i) General. The OBD system must monitor the SCR and/or the lean NO X converting catalyst(s) for proper conversion capability. For engines equipped with SCR systems or other catalyst systems that use an active/intrusive reductant injection (e.g., active lean NO X catalysts that use diesel fuel post-injection or in-exhaust injection), the OBD system must monitor the active/intrusive reductant injection system for proper performance. The individual electronic components (e.g., actuators, valves, sensors, heaters, pumps) in the active/intrusive reductant injection system must be monitored in accordance with the comprehensive component requirements in paragraph (i)(3) of this section. For purposes of this paragraph (g)(6), each catalyst that converts NO X must be monitored either individually or in combination with others. (ii) SCR and lean NO X catalyst malfunction criteria —(A) SCR and lean NO X catalyst conversion efficiency. The OBD system must detect a catalyst malfunction when the catalyst conversion capability decreases to the point that would cause an engine's emissions to exceed the emissions thresholds for NO X aftertreatment systems as shown in Table 1 of this paragraph (g)

or in combination with others. (ii) SCR and lean NO X catalyst malfunction criteria —(A) SCR and lean NO X catalyst conversion efficiency. The OBD system must detect a catalyst malfunction when the catalyst conversion capability decreases to the point that would cause an engine's emissions to exceed the emissions thresholds for NO X aftertreatment systems as shown in Table 1 of this paragraph (g). If no failure or deterioration of the catalyst NO X conversion capability could result in an engine's emissions exceeding any of the applicable emissions thresholds, the OBD system must detect a malfunction when the catalyst has no detectable amount of NO X conversion capability. (B) SCR and lean NO X catalyst active/intrusive reductant delivery performance. The OBD system must detect a malfunction prior to any failure or deterioration of the system to properly regulate reductant delivery (e.g., urea injection, separate injector fuel injection, post injection of fuel, air assisted injection/mixing) that would cause an engine's emissions to exceed any of the applicable emissions thresholds for NO X aftertreatment systems as shown in Table 1 of this paragraph (g). If no failure or deterioration of the reductant delivery system could result in an engine's emissions exceeding any of the applicable thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that it is no longer able to deliver the desired quantity of reductant. (C) SCR and lean NO X catalyst active/intrusive reductant quantity. If the SCR or lean NO X catalyst system uses a reductant other than the fuel used for the engine, or uses a reservoir/tank for the reductant that is separate from the fuel tank used for the engine, the OBD system must detect a malfunction when there is no longer sufficient reductant available (e.g., the reductant tank is empty). (D) SCR and lean NO X catalyst active/intrusive reductant quality

ty. If the SCR or lean NO X catalyst system uses a reductant other than the fuel used for the engine, or uses a reservoir/tank for the reductant that is separate from the fuel tank used for the engine, the OBD system must detect a malfunction when there is no longer sufficient reductant available (e.g., the reductant tank is empty). (D) SCR and lean NO X catalyst active/intrusive reductant quality. If the SCR or lean NO X catalyst system uses a reservoir/tank for the reductant that is separate from the fuel tank used for the engine, the OBD system must detect a malfunction when an improper reductant is used in the reductant reservoir/tank (e.g., the reductant tank is filled with something other than the reductant). (E) SCR and lean NO X catalyst active/intrusive reductant feedback control. See paragraph (i)(6) of this section. (iii) SCR and lean NO X catalyst monitoring conditions. (A) The manufacturers must define the monitoring conditions for malfunctions identified in paragraphs (g)(6)(ii)(A) and (g)(6)(ii)(D) of this section in accordance with paragraphs (c) and (d) of this section. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraph (g)(6)(ii)(A) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (B) The OBD system must monitor continuously for malfunctions identified in paragraphs (g)(6)(ii)(B), (g)(6)(ii)(C), and (g)(6)(ii)(E) of this section. (iv) SCR and lean NO X catalyst MIL activation and DTC storage. (A) For malfunctions identified in paragraph (g)(6)(ii)(A) of this section, the MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section

. (B) The OBD system must monitor continuously for malfunctions identified in paragraphs (g)(6)(ii)(B), (g)(6)(ii)(C), and (g)(6)(ii)(E) of this section. (iv) SCR and lean NO X catalyst MIL activation and DTC storage. (A) For malfunctions identified in paragraph (g)(6)(ii)(A) of this section, the MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. (B) For malfunctions identified in paragraphs (g)(6)(ii)(B), (g)(6)(ii)(C), and (g)(6)(ii)(D) of this section, the manufacturer may delay activating the MIL if the vehicle is equipped with an alternative indicator for notifying the vehicle operator of the malfunction. The alternative indicator must be of sufficient illumination and be located such that it is readily visible to the vehicle operator under all lighting conditions. If the vehicle is not equipped with such an alternative indicator and the OBD MIL activates, the MIL may be immediately deactivated and the corresponding DTC(s) erased once the OBD system has verified that the reductant tank has been refilled properly and the MIL has not been activated for any other malfunction. The Administrator may approve other strategies that provide equivalent assurance that a vehicle operator would be promptly notified and that corrective action would be taken. (C) The monitoring method for the SCR and lean NO X catalyst(s) must be capable of detecting all instances, except diagnostic self-clearing, when a catalyst DTC(s) has been erased but the catalyst has not been replaced (e.g., catalyst over-temperature histogram approaches are not acceptable). (7) NO X adsorber system monitoring —(i) General. The OBD system must monitor the NO X adsorber on engines so-equipped for proper performance. For engines equipped with active/intrusive injection (e.g., in-exhaust fuel and/or air injection) to achieve desorption of the NO X adsorber, the OBD system must monitor the active/intrusive injection system for proper performance

aches are not acceptable). (7) NO X adsorber system monitoring —(i) General. The OBD system must monitor the NO X adsorber on engines so-equipped for proper performance. For engines equipped with active/intrusive injection (e.g., in-exhaust fuel and/or air injection) to achieve desorption of the NO X adsorber, the OBD system must monitor the active/intrusive injection system for proper performance. The individual electronic components (e.g., injectors, valves, sensors) that are used in the active/intrusive injection system must be monitored in accordance with the comprehensive component requirements in paragraph (i)(3) of this section. (ii) NO X adsorber system malfunction criteria —(A) NO X adsorber system capability. The OBD system must detect a NO X adsorber malfunction when its capability (i.e., its combined adsorption and conversion capability) decreases to the point that would cause an engine's NO X emissions to exceed the emissions thresholds for NO X aftertreatment systems as shown in Table 1 of this paragraph (g). If no failure or deterioration of the NO X adsorber capability could result in an engine's NO X emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has no detectable amount of NO X adsorber capability. (B) NO X adsorber system active/intrusive reductant delivery performance. For NO X adsorber systems that use active/intrusive injection (e.g., in-cylinder post fuel injection, in-exhaust air-assisted fuel injection) to achieve desorption of the NO X adsorber, the OBD system must detect a malfunction if any failure or deterioration of the injection system's ability to properly regulate injection causes the system to be unable to achieve desorption of the NO X adsorber. (C) NO X adsorber system feedback control. Malfunction criteria for the NO X adsorber and the NO X adsorber active/instrusive reductant delivery system are contained in paragraph (i)(6) of this section. (iii) NO X adsorber system monitoring conditions

ioration of the injection system's ability to properly regulate injection causes the system to be unable to achieve desorption of the NO X adsorber. (C) NO X adsorber system feedback control. Malfunction criteria for the NO X adsorber and the NO X adsorber active/instrusive reductant delivery system are contained in paragraph (i)(6) of this section. (iii) NO X adsorber system monitoring conditions. (A) The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(7)(ii)(A) of this section in accordance with paragraphs (c) and (d) of this section. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraph (g)(7)(ii)(A) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (B) The OBD system must monitor continuously for malfunctions identified in paragraphs (g)(7)(ii)(B) and (g)(7)(ii)(C) of this section. (iv) NO X adsorber system MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. (8) Diesel particulate filter (DPF) system monitoring —(i) General. The OBD system must monitor the DPF on engines so-equipped for proper performance. For engines equipped with active regeneration systems that use an active/intrusive injection (e.g., in-exhaust fuel injection, in-exhaust fuel/air burner), the OBD system must monitor the active/intrusive injection system for proper performance. The individual electronic components (e.g., injectors, valves, sensors) that are used in the active/intrusive injection system must be monitored in accordance with the comprehensive component requirements in paragraph (i)(3) of this section. (ii) DPF system malfunction criteria —(A) DPF filtering performance

the OBD system must monitor the active/intrusive injection system for proper performance. The individual electronic components (e.g., injectors, valves, sensors) that are used in the active/intrusive injection system must be monitored in accordance with the comprehensive component requirements in paragraph (i)(3) of this section. (ii) DPF system malfunction criteria —(A) DPF filtering performance. The OBD system must detect a malfunction prior to a decrease in the PM filtering capability of the DPF (e.g., cracking, melting, etc.) that would cause an engine's PM emissions to exceed the emissions thresholds for DPF systems as shown in Table 1 of this paragraph (g). If no failure or deterioration of the PM filtering performance could result in an engine's PM emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when no detectable amount of PM filtering occurs. As an alternative to a threshold monitor, the OBD system, on model year 2010 through 2012 engines only, can be designed to detect a malfunction based on a detectable decrease in the expected pressure drop across the DPF for a period of 5 seconds or more. The monitoring area for this alternative is determined using engine speed and load points defined in test cycles and procedures for the supplemental emissions test (SET) under § 86.1360-2007. The monitoring area shall include all engine speed and load points greater than a region bounded by a line connecting mode numbers 2, 6, 3, and 13 (i.e. A100, A75, B50, and C50). At engine speeds greater than “speed C”, the monitor shall run whenever engine load is greater than 50%. For purposes of this paragraph, the detectable change in pressure drop is determined by operating the engine at the B50 engine speed and load point (as described in the SET test procedures), observing the pressure drop on a clean, nominal DPF, and multiplying the observed pressure drop by 0.5 or other factor supported by data and approved by the Administrator

never engine load is greater than 50%. For purposes of this paragraph, the detectable change in pressure drop is determined by operating the engine at the B50 engine speed and load point (as described in the SET test procedures), observing the pressure drop on a clean, nominal DPF, and multiplying the observed pressure drop by 0.5 or other factor supported by data and approved by the Administrator. The detectable change in pressure drop shall be reported in units of kilopascals (kPa). At time of certification, manufacturers shall provide the detectable change in pressure drop value along with OBD data stream parameters recorded with a clean DPF under the following nine engine speed/load operating points of the SET: A50, A75, A100, B50, B75, B100, C50, C75, and C100. The OBD data stream pararmeters to be reported are described in (k)(4)(ii) of this section and shall include the following: Engine speed; calculated load; air flow rate from mass air flow sensor (if so equipped); fuel rate; and DPF delta pressure. (B) DPF regeneration frequency. The OBD system must detect a malfunction when the DPF regeneration frequency increases from (i.e., occurs more often than) the manufacturer's specified regeneration frequency to a level such that it would cause an engine's NMHC emissions to exceed the emissions threshold for DPF systems as shown in Table 1 of this paragraph (g). If no such regeneration frequency exists that could cause NMHC emissions to exceed the applicable emission threshold, the OBD system must detect a malfunction when the DPF regeneration frequency exceeds the manufacturer's specified design limits for allowable regeneration frequency. (C) DPF incomplete regeneration. The OBD system must detect a regeneration malfunction when the DPF does not properly regenerate under manufacturer-defined conditions where regeneration is designed to occur. (D) DPF missing substrate

the OBD system must detect a malfunction when the DPF regeneration frequency exceeds the manufacturer's specified design limits for allowable regeneration frequency. (C) DPF incomplete regeneration. The OBD system must detect a regeneration malfunction when the DPF does not properly regenerate under manufacturer-defined conditions where regeneration is designed to occur. (D) DPF missing substrate. The OBD system must detect a malfunction if either the DPF substrate is completely destroyed, removed, or missing, or if the DPF assembly has been replaced with a muffler or straight pipe. (E) DPF system active/intrusive injection. For DPF systems that use active/intrusive injection (e.g., in-cylinder post fuel injection, in-exhaust air-assisted fuel injection) to achieve regeneration of the DPF, the OBD system must detect a malfunction if any failure or deterioration of the injection system's ability to properly regulate injection causes the system to be unable to achieve regeneration of the DPF. (F) DPF regeneration feedback control. See paragraph (i)(6) of this section. (iii) DPF monitoring conditions. The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (g)(8)(ii) of this section in accordance with paragraphs (c) and (d) of this section, with the exception that monitoring must occur every time the monitoring conditions are met during the drive cycle rather than once per drive cycle as required in paragraph (c)(2) of this section. For OBD systems designed to the alternative malfunction criteria of paragraph (g)(8)(ii)(A) of this section, the alternative DPF monitor shall run continuously whenever engine speed and load conditions are within the monitoring area described in paragraph (g)(8)(ii)(A). The OBD system may make a malfunction or potential malfunction determination during any successful monitoring event but shall include in the enable criteria of any subsequent monitoring events a confirmed successful and complete DPF regeneration

ernative DPF monitor shall run continuously whenever engine speed and load conditions are within the monitoring area described in paragraph (g)(8)(ii)(A). The OBD system may make a malfunction or potential malfunction determination during any successful monitoring event but shall include in the enable criteria of any subsequent monitoring events a confirmed successful and complete DPF regeneration. The subsequent monitoring events must be conducted within an operating period that ensures that the detected malfunction has not “healed” due to trapped particulates in the compromised portion of the DPF substrate. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraph (g)(8)(ii) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (iv) DPF system MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. (9) Exhaust gas sensor and sensor heater monitoring —(i) General. The OBD system must monitor for proper output signal, activity, response rate, and any other parameter that can affect emissions, all exhaust gas sensors (e.g., oxygen, air-fuel ratio, NO X ) used for emission control system feedback (e.g., EGR control/feedback, SCR control/feedback, NO X adsorber control/feedback) and/or as a monitoring device. For engines equipped with heated exhaust gas sensors, the OBD system must monitor the heater for proper performance. (ii) Malfunction criteria for air-fuel ratio sensors located upstream of aftertreatment devices —(A) Sensor performance

NO X ) used for emission control system feedback (e.g., EGR control/feedback, SCR control/feedback, NO X adsorber control/feedback) and/or as a monitoring device. For engines equipped with heated exhaust gas sensors, the OBD system must monitor the heater for proper performance. (ii) Malfunction criteria for air-fuel ratio sensors located upstream of aftertreatment devices —(A) Sensor performance. The OBD system must detect a malfunction prior to any failure or deterioration of the sensor voltage, resistance, impedance, current, response rate, amplitude, offset, or other characteristic(s) that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 1 of this paragraph (g). (B) Circuit integrity. The OBD system must detect malfunctions of the sensor related to a lack of circuit continuity or signal out-of-range values. (C) Feedback function. The OBD system must detect a malfunction of the sensor if the emission control system (e.g., EGR, SCR, or NO X adsorber) is unable to use that sensor as a feedback input (e.g., causes limp-home or open-loop operation). (D) Monitoring function. To the extent feasible, the OBD system must detect a malfunction of the sensor when the sensor output voltage, resistance, impedance, current, amplitude, activity, offset, or other characteristics are no longer sufficient for use as an OBD system monitoring device (e.g., for catalyst, EGR, SCR, or NO X adsorber monitoring). (iii) Malfunction criteria for air-fuel ratio sensors located downstream of aftertreatment devices —(A) Sensor performance. The OBD system must detect a malfunction prior to any failure or deterioration of the sensor voltage, resistance, impedance, current, response rate, amplitude, offset, or other characteristic(s) that would cause an engine's emissions to exceed the emissions thresholds for air-fuel ratio sensors downstream of aftertreatment devices as shown in Table 1 of this paragraph (g). (B) Circuit integrity

e. The OBD system must detect a malfunction prior to any failure or deterioration of the sensor voltage, resistance, impedance, current, response rate, amplitude, offset, or other characteristic(s) that would cause an engine's emissions to exceed the emissions thresholds for air-fuel ratio sensors downstream of aftertreatment devices as shown in Table 1 of this paragraph (g). (B) Circuit integrity. The OBD system must detect malfunctions of the sensor related to a lack of circuit continuity or signal out-of-range values. (C) Feedback function. The OBD system must detect a malfunction of the sensor if the emission control system (e.g., EGR, SCR, or NO X absorber) is unable to use that sensor as a feedback input (e.g., causes limp-home or open-loop operation). (D) Monitoring function. To the extent feasible, the OBD system must detect a malfunction of the sensor when the sensor output voltage, resistance, impedance, current, amplitude, activity, offset, or other characteristics are no longer sufficient for use as an OBD system monitoring device (e.g., for catalyst, EGR, SCR, or NO X absorber monitoring). (iv) Malfunction criteria for NO X sensors —(A) Sensor performance. The OBD system must detect a malfunction prior to any failure or deterioration of the sensor voltage, resistance, impedance, current, response rate, amplitude, offset, or other characteristic(s) that would cause an engine's emissions to exceed the emissions thresholds for NO X sensors as shown in Table 1 of this paragraph (g). (B) Circuit integrity. The OBD system must detect malfunctions of the sensor related to a lack of circuit continuity or signal out-of-range values. (C) Feedback function. The OBD system must detect a malfunction of the sensor if the emission control system (e.g., EGR, SCR, or NO X adsorber) is unable to use that sensor as a feedback input (e.g., causes limp-home or open-loop operation). (D) Monitoring function

ntegrity. The OBD system must detect malfunctions of the sensor related to a lack of circuit continuity or signal out-of-range values. (C) Feedback function. The OBD system must detect a malfunction of the sensor if the emission control system (e.g., EGR, SCR, or NO X adsorber) is unable to use that sensor as a feedback input (e.g., causes limp-home or open-loop operation). (D) Monitoring function. To the extent feasible, the OBD system must detect a malfunction of the sensor when the sensor output voltage, resistance, impedance, current, amplitude, activity, offset, or other characteristics are no longer sufficient for use as an OBD system monitoring device (e.g., for catalyst, EGR, SCR, or NO X adsorber monitoring). (v) Malfunction criteria for other exhaust gas sensors. For other exhaust gas sensors, the manufacturer must submit a monitoring plan to the Administrator for approval. The plan must include data and/or engineering evaluations that demonstrate that the monitoring plan is as reliable and effective as the monitoring required in paragraphs (g)(9)(ii), (g)(9)(iii), (g)(9)(iv) of this section. (vi) Malfunction criteria for exhaust gas sensor heaters. (A) The OBD system must detect a malfunction of the heater performance when the current or voltage drop in the heater circuit is no longer within the manufacturer's specified limits for normal operation (i.e., within the criteria required to be met by the component vendor for heater circuit performance at high mileage). The manufacturer may use other malfunction criteria for heater performance malfunctions. To do so, the manufacturer must be able to demonstrate via data and/or an engineering evaluation that the monitor is reliable and robust. (B) The OBD system must detect malfunctions of the heater circuit including open or short circuits that conflict with the commanded state of the heater (e.g., shorted to 12 Volts when commanded to 0 Volts (ground)). (vii) Monitoring conditions for exhaust gas sensors

so, the manufacturer must be able to demonstrate via data and/or an engineering evaluation that the monitor is reliable and robust. (B) The OBD system must detect malfunctions of the heater circuit including open or short circuits that conflict with the commanded state of the heater (e.g., shorted to 12 Volts when commanded to 0 Volts (ground)). (vii) Monitoring conditions for exhaust gas sensors. (A) The manufacturer must define the monitoring conditions for malfunctions identified in paragraphs (g)(9)(ii)(A), (g)(9)(iii)(A), and (g)(9)(iv)(A) of this section (i.e., sensor performance) in accordance with paragraphs (c) and (d) of this section. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraphs (g)(9)(ii)(A), (g)(9)(iii)(A), and (g)(9)(iv)(A) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (B) The manufacturer must define the monitoring conditions for malfunctions identified in paragraphs (g)(9)(ii)(D), (g)(9)(iii)(D), and (g)(9)(iv)(D) of this section (i.e., monitoring function) in accordance with paragraphs (c) and (d) of this section with the exception that monitoring must occur every time the monitoring conditions are met during the drive cycle rather than once per drive cycle as required in paragraph (c)(2) of this section. (C) Except as provided for in paragraph (g)(9)(vii)(D) of this section, the OBD system must monitor continuously for malfunctions identified in paragraphs (g)(9)(ii)(B), (g)(9)(ii)(C), (g)(9)(iii)(B), (g)(9)(iii)(C), (g)(9)(iv)(B), (g)(9)(iv)(C) of this section (i.e., circuit integrity and feedback function). (D) A manufacturer may request approval to disable continuous exhaust gas sensor monitoring when an exhaust gas sensor malfunction cannot be distinguished from other effects (e.g., disable monitoring for out-of-range on the low side during fuel cut conditions)

g)(9)(ii)(C), (g)(9)(iii)(B), (g)(9)(iii)(C), (g)(9)(iv)(B), (g)(9)(iv)(C) of this section (i.e., circuit integrity and feedback function). (D) A manufacturer may request approval to disable continuous exhaust gas sensor monitoring when an exhaust gas sensor malfunction cannot be distinguished from other effects (e.g., disable monitoring for out-of-range on the low side during fuel cut conditions). To do so, the manufacturer must demonstrate via data and/or engineering analyses that a properly functioning sensor cannot be distinguished from a malfunctioning sensor and that the disablement interval is limited only to that necessary for avoiding falsemalfunction detection. (viii) Monitoring conditions for exhaust gas sensor heaters —(A) The manufacturer must define monitoring conditions for malfunctions identified in paragraph (g)(9)(vi)(A) of this section (i.e., sensor heater performance) in accordance with paragraphs (c) and (d) of this section. (B) The OBD system must monitor continuously for malfunctions identified in paragraph (g)(9)(vi)(B) of this section (i.e., circuit malfunctions). (ix) Exhaust gas sensor and sensor heater MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. (10) Variable Valve Timing (VVT) system monitoring —(i) General. The OBD system must monitor the VVT system on engines so equipped for target error and slow response malfunctions. The individual electronic components (e.g., actuators, valves, sensors) that are used in the VVT system must be monitored in accordance with the comprehensive components requirements in paragraph (i)(3) of this section. (ii) VVT system malfunction criteria —(A) VVT system target error

The OBD system must monitor the VVT system on engines so equipped for target error and slow response malfunctions. The individual electronic components (e.g., actuators, valves, sensors) that are used in the VVT system must be monitored in accordance with the comprehensive components requirements in paragraph (i)(3) of this section. (ii) VVT system malfunction criteria —(A) VVT system target error. The OBD system must detect a malfunction prior to any failure or deterioration in the capability of the VVT system to achieve the commanded valve timing and/or control within a crank angle and/or lift tolerance that would cause an engine's emissions to exceed the emission thresholds for “other monitors” as shown in Table 1 of this paragraph (g). (B) VVT slow response. The OBD system must detect a malfunction prior to any failure or deterioration in the capability of the VVT system to achieve the commanded valve timing and/or control within a manufacturer-specified time that would cause an engine's emissions to exceed the emission thresholds for “other monitors” as shown in Table 1 of this paragraph (g). (C) For engines in which no failure or deterioration of the VVT system could result in an engine's emissions exceeding the applicable emissions thresholds of paragraphs (g)(10)(ii)(A) and (g)(10)(ii)(B) of this section, the OBD system must detect a malfunction of the VVT system when proper functional response of the system to computer commands does not occur. (iii) VVT system monitoring conditions. Manufacturers must define the monitoring conditions for VVT system malfunctions identified in paragraph (g)(10)(ii) of this section in accordance with paragraphs (c) and (d) of this section, with the exception that monitoring must occur every time the monitoring conditions are met during the drive cycle rather than once per drive cycle as required in paragraph (c)(2) of this section

ng conditions. Manufacturers must define the monitoring conditions for VVT system malfunctions identified in paragraph (g)(10)(ii) of this section in accordance with paragraphs (c) and (d) of this section, with the exception that monitoring must occur every time the monitoring conditions are met during the drive cycle rather than once per drive cycle as required in paragraph (c)(2) of this section. For purposes of tracking and reporting as required in paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraph (g)(10)(ii) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (iv) VVT MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. (h) OBD monitoring requirements for gasoline-fueled/spark-ignition engines. The following table shows the thresholds at which point certain components or systems, as specified in this paragraph (h), are considered malfunctioning. Table 2—OBD Emissions Thresholds for Gasoline-Fueled/Spark-Ignition Engines Meant for Placement in Applications Greater Than 14,000 Pounds GVWR (g/bhp-hr) Component NO X NMHC CO § 86.010-18 reference Catalyst system 1.75x std 1.75x std (h)(6) Evaporative emissions control system 0.150 inch leak (h)(7) “Other monitors” with emissions thresholds 1.5x std 1.5x std 1.5x std (h)(1), (h)(2), (h)(3), (h)(4), (h)(5), (h)(8), (h)(9) Notes: 1.75x std means a multiple of 1.75 times the applicable emissions standard; these emissions thresholds apply to the monitoring requirements of paragraph (h) of this section; The evaporative emissions control system threshold is not, technically, an emissions threshold but rather a leak size that must be detected; nonetheless, for ease we refer to this as the threshold. (1) Fuel system monitoring —(i) General

eans a multiple of 1.75 times the applicable emissions standard; these emissions thresholds apply to the monitoring requirements of paragraph (h) of this section; The evaporative emissions control system threshold is not, technically, an emissions threshold but rather a leak size that must be detected; nonetheless, for ease we refer to this as the threshold. (1) Fuel system monitoring —(i) General. The OBD system must monitor the fuel delivery system to determine its ability to provide compliance with emission standards. (ii) Fuel system malfunction criteria. (A) The OBD system must detect a malfunction of the fuel delivery system (including feedback control based on a secondary oxygen sensor) when the fuel delivery system is unable to maintain an engine's emissions at or below the emissions thresholds for “other monitors” as shown in Table 2 of this paragraph (h). (B) Except as provided for in paragraph (h)(1)(ii)(C) of this section, if the engine is equipped with adaptive feedback control, the OBD system must detect a malfunction when the adaptive feedback control has used up all of the adjustment allowed by the manufacturer. (C) If the engine is equipped with feedback control that is based on a secondary oxygen (or equivalent) sensor, the OBD system is not required to detect a malfunction of the fuel system solely when the feedback control based on a secondary oxygen sensor has used up all of the adjustment allowed by the manufacturer. However, if a failure or deterioration results in engine emissions that exceed the emissions thresholds for “other monitors” as shown in Table 2 of this paragraph (h), the OBD system is required to detect a malfunction. (D) The OBD system must detect a malfunction whenever the fuel control system fails to enter closed loop operation following engine start within a manufacturer specified time interval. The specified time interval must be supported by data and/or engineering analyses submitted by the manufacturer

onitors” as shown in Table 2 of this paragraph (h), the OBD system is required to detect a malfunction. (D) The OBD system must detect a malfunction whenever the fuel control system fails to enter closed loop operation following engine start within a manufacturer specified time interval. The specified time interval must be supported by data and/or engineering analyses submitted by the manufacturer. (E) The manufacturer may adjust the malfunction criteria and/or monitoring conditions to compensate for changes in altitude, for temporary introduction of large amounts of purge vapor, or for other similar identifiable operating conditions when such conditions occur. (iii) Fuel system monitoring conditions. The fuel system must be monitored continuously for the presence of a malfunction. (iv) Fuel system MIL activation and DTC storage. (A) A pending DTC must be stored immediately upon the fuel system exceeding the malfunction criteria established in paragraph (h)(1)(ii) of this section. (B) Except as provided for in paragraph (h)(1)(iv)(C) of this section, if a pending DTC is stored, the OBD system must activate the MIL immediately and store a MIL-on DTC if a malfunction is again detected during either the drive cycle immediately following storage of the pending DTC regardless of the conditions encountered during that drive cycle, or on the next drive cycle in which similar conditions are encountered to those that occurred when the pending DTC was stored. Similar conditions means engine conditions having an engine speed within 375 rpm, load conditions within 20 percent, and the same warm-up status (i.e., cold or hot) as the engine conditions stored pursuant to paragraph (h)(1)(iv)(E) of this section. Other definitions of similar conditions may be used but must result in comparable timeliness and reliability in detecting similar engine operation

ed. Similar conditions means engine conditions having an engine speed within 375 rpm, load conditions within 20 percent, and the same warm-up status (i.e., cold or hot) as the engine conditions stored pursuant to paragraph (h)(1)(iv)(E) of this section. Other definitions of similar conditions may be used but must result in comparable timeliness and reliability in detecting similar engine operation. (C) The pending DTC may be erased at the end of the next drive cycle in which similar conditions have been encountered without having again exceeded the specified fuel system malfunction criteria. The pending DTC may also be erased if similar conditions are not encountered during the 80 drive cycles immediately following detection of the potential malfunction for which the pending DTC was stored. (D) Storage of freeze frame conditions. The OBD system must store and erase freeze frame conditions either in conjunction with storing and erasing a pending DTC or in conjunction with storing and erasing a MIL-on DTC. Freeze frame information associated with a fuel system malfunction shall be stored in preference to freeze frame information required elsewhere in paragraphs (h) or (i) of this section. (E) Storage of fuel system conditions for determining similar conditions of operation. The OBD must store the engine speed, load, and warm-up status present at the time it first detects a potential malfunction meeting the criteria of paragraph (h)(1)(ii) of this section and stores a pending DTC. (F) Deactivating the MIL. The MIL may be extinguished after three sequential driving cycles in which similar conditions have been encountered without detecting a malfunction of the fuel system. (2) Engine misfire monitoring —(i) General. (A) The OBD system must monitor the engine for misfire causing catalyst damage and misfire causing excess emissions. (B) The OBD system must identify the specific cylinder that is misfiring

he MIL may be extinguished after three sequential driving cycles in which similar conditions have been encountered without detecting a malfunction of the fuel system. (2) Engine misfire monitoring —(i) General. (A) The OBD system must monitor the engine for misfire causing catalyst damage and misfire causing excess emissions. (B) The OBD system must identify the specific cylinder that is misfiring. The manufacturer may store a general misfire DTC instead of a cylinder specific DTC under certain operating conditions. To do so, the manufacturer must submit data and/or engineering analyses that demonstrate that the misfiring cylinder cannot be identified reliably when the conditions occur. (C) If more than one cylinder is misfiring, a separate DTC must be stored to indicate that multiple cylinders are misfiring unless otherwise allowed by this paragraph (h)(2). When identifying multiple cylinder misfire, the OBD system is not required to also identify using separate DTCs each of the misfiring cylinders individually. If more than 90 percent of the detected misfires occur in a single cylinder, an appropriate DTC may be stored that indicates the specific misfiring cylinder rather than storing the multiple cylinder misfire DTC. If two or more cylinders individually have more than 10 percent of the total number of detected misfires, a multiple cylinder DTC must be stored. (ii) Engine misfire malfunction criteria —(A) Misfire causing catalyst damage. The manufacturer must determine the percentage of misfire evaluated in 200 revolution increments for each engine speed and load condition that would result in a temperature that causes catalyst damage. If this percentage of misfire is exceeded, it shall be considered a malfunction that must be detected. For every engine speed and load condition for which this percentage of misfire is determined to be lower than five percent, the manufacturer may set the malfunction criteria at five percent

ts for each engine speed and load condition that would result in a temperature that causes catalyst damage. If this percentage of misfire is exceeded, it shall be considered a malfunction that must be detected. For every engine speed and load condition for which this percentage of misfire is determined to be lower than five percent, the manufacturer may set the malfunction criteria at five percent. The manufacturer may use a longer interval than 200 revolutions but only for determining, on a given drive cycle, the first misfire exceedance as provided in paragraph (h)(2)(iv)(A) of this section. To do so, the manufacturer must demonstrate that the interval is not so long that catalyst damage would occur prior to the interval being elapsed. (B) Misfire causing emissions to exceed the applicable thresholds. The manufacturer must determine the percentage of misfire evaluated in 1000 revolution increments that would cause emissions from an emissions durability demonstration engine to exceed the emissions thresholds for “other monitors” as shown in Table 2 of this paragraph (h) if that percentage of misfire were present from the beginning of the test. If this percentage of misfire is exceeded, regardless of the pattern of misfire events (e.g., random, equally spaced, continuous), it shall be considered a malfunction that must be detected. To establish this percentage of misfire, the manufacturer must use misfire events occurring at equally spaced, complete engine cycle intervals, across randomly selected cylinders throughout each 1000-revolution increment. If this percentage of misfire is determined to be lower than one percent, the manufacturer may set the malfunction criteria at one percent. The manufacturer may use a longer interval than 1000 revolutions. To do so, the manufacturer must demonstrate that the strategy would be equally effective and timely at detecting misfire. (iii) Engine misfire monitoring conditions

ch 1000-revolution increment. If this percentage of misfire is determined to be lower than one percent, the manufacturer may set the malfunction criteria at one percent. The manufacturer may use a longer interval than 1000 revolutions. To do so, the manufacturer must demonstrate that the strategy would be equally effective and timely at detecting misfire. (iii) Engine misfire monitoring conditions. (A) The OBD system must monitor continuously for misfire under the following conditions: from no later than the end of the second crankshaft revolution after engine start; during the rise time and settling time for engine speed to reach the desired idle engine speed at engine start-up (i.e., “flare-up” and “flare-down”); and, under all positive torque engine speeds and load conditions except within the engine operating region bound by the positive torque line (i.e., engine load with the transmission in neutral), and the points represented by an engine speed of 3000 rpm with the engine load at the positive torque line and the redline engine speed with the engine's manifold vacuum at four inches of mercury lower than that at the positive torque line. For this purpose, redline engine speed is defined as either the recommended maximum engine speed as displayed on the instrument panel tachometer, or the engine speed at which fuel shutoff occurs. (B) If an OBD monitor cannot detect all misfire patterns under all required engine speed and load conditions as required by paragraph (h)(2)(iii)(A) of this section, the OBD system may still be acceptable

For this purpose, redline engine speed is defined as either the recommended maximum engine speed as displayed on the instrument panel tachometer, or the engine speed at which fuel shutoff occurs. (B) If an OBD monitor cannot detect all misfire patterns under all required engine speed and load conditions as required by paragraph (h)(2)(iii)(A) of this section, the OBD system may still be acceptable. The Administrator will evaluate the following factors in making a determination: The magnitude of the region(s) in which misfire detection is limited; the degree to which misfire detection is limited in the region(s) (i.e., the probability of detection of misfire events); the frequency with which said region(s) are expected to be encountered in-use; the type of misfire patterns for which misfire detection is troublesome; and demonstration that the monitoring technology employed is not inherently incapable of detecting misfire under the required conditions (i.e., compliance can be achieved on other engines). The evaluation will be based on the following misfire patterns: equally spaced misfire occurring on randomly selected cylinders; single cylinder continuous misfire; and paired cylinder (cylinders firing at the same crank angle) continuous misfire. (C) The manufacturer may use monitoring system that has reduced misfire detection capability during the portion of the first 1000 revolutions after engine start that a cold start emission reduction strategy is active that reduces engine torque (e.g., spark retard strategies). To do so, the manufacturer must demonstrate that the probability of detection is greater than or equal to 75 percent during the worst case condition (i.e., lowest generated torque) for a vehicle operated continuously at idle (park/neutral idle) on a cold start between 50 and 86 degrees Fahrenheit and that the technology cannot reliably detect a higher percentage of the misfire events during the conditions

, the manufacturer must demonstrate that the probability of detection is greater than or equal to 75 percent during the worst case condition (i.e., lowest generated torque) for a vehicle operated continuously at idle (park/neutral idle) on a cold start between 50 and 86 degrees Fahrenheit and that the technology cannot reliably detect a higher percentage of the misfire events during the conditions. (D) The manufacturer may disable misfire monitoring or use an alternative malfunction criterion when misfire cannot be distinguished from other effects. To do so, the manufacturer must demonstrate that the disablement interval or the period of use of an alternative malfunction criterion is limited only to that necessary for avoiding false detection and for one or more of the following operating conditions: Rough road; fuel cut; gear changes for manual transmission vehicles; traction control or other vehicle stability control activation such as anti-lock braking or other engine torque modifications to enhance vehicle stability; off-board control or intrusive activation of vehicle components or monitors during service or assembly plant testing; portions of intrusive evaporative system or EGR monitors that can significantly affect engine stability (i.e., while the purge valve is open during the vacuum pull-down of an evaporative system leak check but not while the purge valve is closed and the evaporative system is sealed or while an EGR monitor causes the EGR valve to be cycled intrusively on and off during positive torque conditions); or, engine speed, load, or torque transients due to throttle movements more rapid than those that occur over the FTP cycle for the worst case engine within each engine family

n evaporative system leak check but not while the purge valve is closed and the evaporative system is sealed or while an EGR monitor causes the EGR valve to be cycled intrusively on and off during positive torque conditions); or, engine speed, load, or torque transients due to throttle movements more rapid than those that occur over the FTP cycle for the worst case engine within each engine family. In general, the Administrator will not approve disablement for conditions involving normal air conditioning compressor cycling from on-to-off or off-to-on, automatic transmission gear shifts (except for shifts occurring during wide open throttle operation), transitions from idle to off-idle, normal engine speed or load changes that occur during the engine speed rise time and settling time (i.e., “flare-up” and “flare-down”) immediately after engine starting without any vehicle operator-induced actions (e.g., throttle stabs), or excess acceleration (except for acceleration rates that exceed the maximum acceleration rate obtainable at wide open throttle while the vehicle is in gear due to abnormal conditions such as slipping of a clutch). The Administrator may approve misfire monitoring disablement or use of an alternate malfunction criterion for any other condition on a case by case basis upon determining that the manufacturer has demonstrated that the request is based on an unusual or unforeseen circumstance and that it is applying the best available computer and monitoring technology. (E) For engines with more than eight cylinders that cannot meet the requirements of paragraph (h)(2)(iii)(A) of this section, a manufacturer may use alternative misfire monitoring conditions

e basis upon determining that the manufacturer has demonstrated that the request is based on an unusual or unforeseen circumstance and that it is applying the best available computer and monitoring technology. (E) For engines with more than eight cylinders that cannot meet the requirements of paragraph (h)(2)(iii)(A) of this section, a manufacturer may use alternative misfire monitoring conditions. Such use must be based on data and/or an engineering evaluation submitted by the manufacturer that demonstrate that misfire detection throughout the required operating region cannot be achieved when employing proven monitoring technology (i.e., a technology that provides for compliance with these requirements on other engines) and provided misfire is detected to the fullest extent permitted by the technology. However, the misfire detection system must still monitor during all positive torque operating conditions encountered during an FTP cycle. (iv) MIL activation and DTC storage for engine misfire causing catalyst damage —(A) Pending DTCs. A pending DTC must be stored immediately if, during a single drive cycle, the specified misfire percentage described in paragraph (h)(2)(ii)(A) of this section is exceeded three times when operating in the positive torque region encountered during a FTP cycle or is exceeded on a single occasion when operating at any other engine speed and load condition in the positive torque region defined in paragraph (h)(2)(iii)(A) of this section. Immediately after a pending DTC is stored pursuant to this paragraph, the MIL must blink once per second at all times during the drive cycle that engine misfire is occurring. The MIL may be deactivated during those times that misfire is not occurring. If, at the time that a catalyst damaging misfire malfunction occurs, the MIL is already activated for a malfunction other than misfire, the MIL must still blink once per second at all times during the drive cycle that engine misfire is occurring

second at all times during the drive cycle that engine misfire is occurring. The MIL may be deactivated during those times that misfire is not occurring. If, at the time that a catalyst damaging misfire malfunction occurs, the MIL is already activated for a malfunction other than misfire, the MIL must still blink once per second at all times during the drive cycle that engine misfire is occurring. If misfire ceases, the MIL must stop blinking but remain activated as appropriate in accordance with the other malfunction. (B) MIL-on DTCs. If a pending DTC is stored in accordance with paragraph (h)(2)(iv)(A) of this section, the OBD system must immediately store a MIL-on DTC if the percentage of misfire described in paragraph (h)(2)(ii)(A) of this section is again exceeded one or more times during either the drive cycle immediately following storage of the pending DTC, regardless of the conditions encountered during that drive cycle, or on the next drive cycle in which similar conditions are encountered to those that occurred when the pending DTC was stored. If, during a previous drive cycle, a pending DTC is stored in accordance with paragraph (h)(2)(iv)(A) of this section, a MIL-on DTC must be stored immediately upon exceeding the percentage misfire described in paragraph (h)(2)(ii)(A) of this section regardless of the conditions encountered. Upon storage of a MIL-on DTC, the MIL must blink once per second at all times during the drive cycle that engine misfire is occurring. If misfire ceases, the MIL must stop blinking but remain activated until the conditions are met for extinguishing the MIL. (C) Erasure of pending DTCs. Pending DTCs stored in accordance with paragraph (h)(2)(iv)(A) of this section must be erased at the end of the next drive cycle in which similar conditions are encountered to those that occurred when the pending DTC was stored provided no exceedances have been detected of the misfire percentage described in paragraph (h)(2)(ii)(A) of this section

xtinguishing the MIL. (C) Erasure of pending DTCs. Pending DTCs stored in accordance with paragraph (h)(2)(iv)(A) of this section must be erased at the end of the next drive cycle in which similar conditions are encountered to those that occurred when the pending DTC was stored provided no exceedances have been detected of the misfire percentage described in paragraph (h)(2)(ii)(A) of this section. The pending DTC may also be erased if similar conditions are not encountered during the next 80 drive cycles immediately following storage of the pending DTC. (D) Exemptions for engines with fuel shutoff and default fuel control. In engines that provide for fuel shutoff and default fuel control to prevent over fueling during catalyst damaging misfire conditions, the MIL need not blink as required by paragraphs (h)(2)(iv)(A) and (h)(2)(iv)(B) of this section. Instead, the MIL may be activated continuously upon misfire detection provided that the fuel shutoff and default fuel control are activated immediately upon misfire detection. Fuel shutoff and default fuel control may be deactivated only when the engine is outside of the misfire range except that the manufacturer may periodically, but not more than once every 30 seconds, deactivate fuel shutoff and default fuel control to determine if the catalyst damaging misfire is still occurring. Normal fueling and fuel control may be resumed if the catalyst damaging misfire is no longer occurring. (E) The manufacturer may use a strategy that activates the MIL continuously rather than blinking the MIL during extreme catalyst damage misfire conditions (i.e., catalyst damage misfire occurring at all engine speeds and loads). Use of such a strategy must be limited to catalyst damage misfire levels that cannot be avoided during reasonable driving conditions. To use such a strategy, the manufacturer must be able to demonstrate that the strategy will encourage operation of the vehicle in conditions that will minimize catalyst damage (e.g., at low engine speeds and loads)

misfire occurring at all engine speeds and loads). Use of such a strategy must be limited to catalyst damage misfire levels that cannot be avoided during reasonable driving conditions. To use such a strategy, the manufacturer must be able to demonstrate that the strategy will encourage operation of the vehicle in conditions that will minimize catalyst damage (e.g., at low engine speeds and loads). (v) MIL activation and DTC storage for engine misfire causing emissions to exceed applicable emissions thresholds. (A) Immediately upon detection, during the first 1000 revolutions after engine start of the misfire percentage described in paragraph (h)(2)(ii)(B) of this section, a pending DTC must be stored. If such a pending DTC is stored already and another such exceedance of the misfire percentage is detected within the first 1000 revolutions after engine start on any subsequent drive cycle, the MIL must activate and a MIL-on DTC must be stored. The pending DTC may be erased if, at the end of the next drive cycle in which similar conditions are encountered to those that occurred when the pending DTC was stored, there has been no exceedance of the misfire percentage described in paragraph (h)(2)(ii)(B) of this section. The pending DTC may also be erased if similar conditions are not encountered during the next 80 drive cycles immediately following storage of the pending DTC. (B) No later than the fourth detection during a single drive cycle, following the first 1000 revolutions after engine start of the misfire percentage described in paragraph (h)(2)(ii)(B) of this section, a pending DTC must be stored

section. The pending DTC may also be erased if similar conditions are not encountered during the next 80 drive cycles immediately following storage of the pending DTC. (B) No later than the fourth detection during a single drive cycle, following the first 1000 revolutions after engine start of the misfire percentage described in paragraph (h)(2)(ii)(B) of this section, a pending DTC must be stored. If such a pending DTC is stored already, then the MIL must activate and a MIL-on DTC must be stored within 10 seconds of the fourth detection of the misfire percentage described in paragraph (h)(2)(ii)(B) of this section during either the drive cycle immediately following storage of the pending DTC, regardless of the conditions encountered during that drive cycle excepting those conditions within the first 1000 revolutions after engine start, or on the next drive cycle in which similar conditions are encountered to those that occurred when the pending DTC was stored excepting those conditions within the first 1000 revolutions after engine start. The pending DTC may be erased if, at the end of the next drive cycle in which similar conditions are encountered to those that occurred when the pending DTC was stored, there has been no exceedance of the misfire percentage described in paragraph (h)(2)(ii)(B) of this section. The pending DTC may also be erased if similar conditions are not encountered during the next 80 drive cycles immediately following storage of the pending DTC. (vi) Storage of freeze frame conditions for engine misfire. (A) The OBD system must store and erase freeze frame conditions (as defined in paragraph (k)(4)(iii) of this section) either in conjunction with storing and erasing a pending DTC or in conjunction with storing and erasing a MIL-on DTC

ons are not encountered during the next 80 drive cycles immediately following storage of the pending DTC. (vi) Storage of freeze frame conditions for engine misfire. (A) The OBD system must store and erase freeze frame conditions (as defined in paragraph (k)(4)(iii) of this section) either in conjunction with storing and erasing a pending DTC or in conjunction with storing and erasing a MIL-on DTC. (B) If, upon storage of a DTC as required by paragraphs (h)(2)(iv) and (h)(2)(v) of this section, there already exist stored freeze frame conditions for a malfunction other than a misfire or fuel system malfunction (see paragraph (h)(1) of this section) then the stored freeze frame information shall be replaced with freeze frame information associated with the misfire malfunction. (vii) Storage of engine conditions in association with engine misfire. Upon detection of the misfire percentages described in paragraphs (h)(2)(ii)(A) and (h)(2)(ii)(B) of this section, the following engine conditions must be stored for use in determining similar conditions: Engine speed, load, and warm up status of the first misfire event that resulted in pending DTC storage. (viii) MIL deactivation in association with engine misfire. The MIL may be deactivated after three sequential drive cycles in which similar conditions have been encountered without an exceedance of the misfire percentages described in paragraphs (h)(2)(ii)(A) and (h)(2)(ii)(B) of this section. (3) Exhaust gas recirculation system monitoring —(i) General. The OBD system must monitor the EGR system on engines so equipped for low and high flow rate malfunctions. The individual electronic components (e.g., actuators, valves, sensors) that are used in the EGR system must be monitored in accordance with the comprehensive component requirements in paragraph (i)(3) of this section. (ii) EGR system malfunction criteria

ation system monitoring —(i) General. The OBD system must monitor the EGR system on engines so equipped for low and high flow rate malfunctions. The individual electronic components (e.g., actuators, valves, sensors) that are used in the EGR system must be monitored in accordance with the comprehensive component requirements in paragraph (i)(3) of this section. (ii) EGR system malfunction criteria. (A) The OBD system must detect a malfunction of the EGR system prior to a decrease from the manufacturer's specified EGR flow rate that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 2 of this paragraph (h). For engines in which no failure or deterioration of the EGR system that causes a decrease in flow could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has no detectable amount of EGR flow. (B) The OBD system must detect a malfunction of the EGR system prior to an increase from the manufacturer's specified EGR flow rate that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 2 of this paragraph (h). For engines in which no failure or deterioration of the EGR system that causes an increase in flow could result in an engine's emissions exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that it cannot reduce EGR flow. (iii) EGR system monitoring conditions. (A) The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (h)(3)(ii) of this section in accordance with paragraphs (c) and (d) of this section

ons exceeding the applicable emissions thresholds, the OBD system must detect a malfunction when the system has reached its control limits such that it cannot reduce EGR flow. (iii) EGR system monitoring conditions. (A) The manufacturer must define the monitoring conditions for malfunctions identified in paragraph (h)(3)(ii) of this section in accordance with paragraphs (c) and (d) of this section. For purposes of tracking and reporting as required by paragraph (d)(1) of this section, all monitors used to detect malfunctions identified in paragraph (h)(3)(ii) of this section must be tracked separately but reported as a single set of values as specified in paragraph (e)(1)(iii) of this section. (B) The manufacturer may disable temporarily the EGR monitor under conditions when monitoring may not be reliable (e.g., when freezing may affect performance of the system). To do so, the manufacturer must be able to demonstrate that the monitor is unreliable when such conditions exist. (iv) EGR system MIL activation and DTC storage. The MIL must activate and DTCs must be stored according to the provisions of paragraph (b) of this section. (4) Cold start emission reduction strategy monitoring —(i) General. If an engine incorporates a specific engine control strategy to reduce cold start emissions, the OBD system must monitor the key components (e.g., idle air control valve), other than secondary air, while the control strategy is active to ensure proper operation of the control strategy. (ii) Cold start strategy malfunction criteria. (A) The OBD system must detect a malfunction prior to any failure or deterioration of the individual components associated with the cold start emission reduction control strategy that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 2 of this paragraph (h)

er operation of the control strategy. (ii) Cold start strategy malfunction criteria. (A) The OBD system must detect a malfunction prior to any failure or deterioration of the individual components associated with the cold start emission reduction control strategy that would cause an engine's emissions to exceed the emissions thresholds for “other monitors” as shown in Table 2 of this paragraph (h). The manufacturer must establish the malfunction criteria based on data from one or more representative engine(s) and provide an engineering evaluation for establishing the malfunction criteria for the remainder of the manufacturer's product line. (B) Where no failure or deterioration of a component used for the cold start emission reduction strategy could result in an engine's emissions exceeding the applicable emissions thresholds, the individual component must be monitored for proper functional response while the control strategy is active in accordance with the malfunction criteria in paragraphs (i)(3)(ii) and (i)(3)(iii) of this section. (iii) Cold start strategy monitoring conditions. The manufacturer must define monitoring conditions for malfunctions identified in paragraph (h)(4)(ii) of this section in accordance with paragraphs (c) and

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