CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 86—CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES > SUBPART A—General Provisions for Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles, Light-Duty Trucks and Heavy-Duty Engines, and for 1985 and Later Model Year New Gaso > 86.010-18—On-board Diagnostics for engines used in applications greater than 14,000 pounds GVWR.

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

(a) General. According to the implementation schedule shown in paragraph (o) of this section, 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 system is required to detect all malfunctions specified in paragraphs (g), (h), and (i) of this § 86.010-18 although 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. 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.
(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. 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). 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).
(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. 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.
(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 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.
(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.
(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. (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.
(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.
(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); NOX 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, NOX 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).
(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. (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. 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. 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.
(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).
(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).
(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).
(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).
(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.
(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. 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, NOX catalyst bank 1, NOX catalyst bank 2, exhaust gas sensor bank 1, exhaust gas sensor bank 2, EGR/VVT system, DPF, boost pressure control system, and NOX 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. (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.
(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.
(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.
(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.
(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 C