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(continued)
(a) All 1988 and subsequent model year passenger cars, light-duty trucks, and medium-duty vehicles equipped with a three-way catalyst system and feedback control shall be equipped with a means of informing the vehicle operator of the malfunction of computer-sensed emission-related components, and of the on-board computer processor, and of the malfunction of the emission-related functioning of the fuel metering device and EGR system on vehicles so equipped, and which provides for on-board diagnosis of the likely area of the malfunction without the aid of any external device. The system shall include a means of informing the vehicle operator, upon initiation of engine starting, that it is functioning properly. No malfunction and diagnostic system shall be required for malfunctions which would significantly impair vehicle driveability or prevent engine starting.
(b) This section shall be implemented as specified in this subsection or by any means determined by the executive officer to meet the requirements of this section:
The vehicles shall be equipped with a malfunction indicator light and an on-board self-diagnostic system. The on-board computer processor shall interrogate input parameters from computer-sensed emission-related components and shall also interrogate the functioning of the fuel metering device and of the EGR system on vehicles so equipped. Upon detection of a malfunction of any such component, device, or system, the computer processor shall cause the malfunction indicator light to illuminate. An on-board computer processor malfunction shall also cause the malfunction indicator light to illuminate. In the case of any such component, device or system whose malfunction would significantly impair vehicle driveability or prevent engine starting, no malfunction indication or diagnostic code shall be required. The indicator light shall also illuminate in the engine-run key position before engine cranking to indicate that the malfunction indicator light is functioning. The self-diagnostic system shall provide an on-board means of identifying, without the aid of any external device, the likely area responsible for the detected malfunction when the vehicle is serviced. The malfunction indicator light shall be located on the instrument panel and shall when illuminated, display the phrase "Check Engine" or "Service Engine Soon" or may display such other phrase determined by the executive officer to be likely to cause a vehicle owner to seek corrective action.
(c) For purposes of this section:
(1) A "computer-sensed emissions-related component of the three-way catalyst emission control system" means a component which provides emission control system input to the on-board computer processor.
(2) "Malfunction" means the partial or total failure of one or more computer-sensed emission-related components or the on-board computer processor, or of the emission-related functioning of a fuel metering device or EGR system to a degree which would likely cause the emissions of an average certification vehicle with the failure or failures, individually or in combination, to exceed the emissions standards applicable pursuant to Subchapter 1 (commencing with Section 1900), Chapter 3 of Title 13.
(d) The executive officer shall grant an extension for compliance with the requirements of this section with respect to a specific vehicle model or engine family if a manufacturer demonstrates that it cannot modify a present electronic control system by the 1988 model year because major design system changes not consistent with the manufacturer's projected changeover schedule would be needed to comply with the provisions of this regulation. The period of extension shall not exceed that necessary to enable modification of the electronic system in accordance with the manufacturer's projected changeover schedule or three years, whichever first occurs. Any manufacturer requesting an extension shall, no later than July 1, 1986, submit to the executive officer of the state board an application setting forth the required demonstration and specifying the period for which the extension is requested.


Note: Authority cited: Sections 39600, 39601 and 43013, Health and Safety Code. Reference: Sections 39002, 39003, 43000, 43013, 43100, 43101, 43102, 43104, 43105 and 43204, Health and Safety Code.


s 1968.1. Malfunction and Diagnostic System Requirements -1994 and Subsequent Model-Year Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and Engines.
(a) GENERAL REQUIREMENTS
(1.0) All 1994 and subsequent model-year passenger cars, light-duty trucks, and medium-duty vehicles shall be equipped with a malfunction indicator light (MIL) located on the instrument panel that will automatically inform the vehicle operator in the event of a malfunction of any powertrain components which can affect emissions and which provide input to, or receive output from, the on-board computer(s) or of the malfunction of the on-board computer(s) itself. The MIL shall not be used for any other purpose.
(1.1) The MIL shall be of sufficient illumination and location to be readily visible under all lighting conditions. The MIL shall illuminate in the engine-run key position before engine cranking to indicate that the MIL is functional and shall, when illuminated, display the phrase "Check Engine" or "Service Engine Soon." The word "Powertrain" may be substituted for "Engine" in the previous phrase. Alternatively, the International Standards Organization (ISO) engine symbol may be substituted for the word "Engine," or for the entire phrase.
(1.2) All 1994 and subsequent model-year passenger cars, light-duty trucks, and medium-duty vehicles required to have MIL pursuant to (1.0) above shall also be equipped with an on-board diagnostic system capable of identifying the likely area of malfunction by means of fault codes stored in computer memory. These vehicles shall be equipped with a standardized electrical connector to provide access to the stored fault codes. Specific performance requirements are listed below. A glossary of terms is contained in subsection (n). Unless otherwise noted, all section references refer to section 1968.1 of Title 13, CCR.
(1.3) Any reference to vehicles in this regulation shall also include medium-duty vehicles with engines certified on an engine dynamometer.
(1.4) For Low Emission Vehicles (LEV), the Executive Officer shall revise the emission threshold for a malfunction on any check if the most reliable monitoring method developed requires a higher threshold to prevent significant errors of commission in detecting a malfunction.
(1.5) For every case in which a malfunction is to be noted when an emission threshold is exceeded (e.g., emissions in excess of 1.5 times the standard), the manufacturer may perform only a functional check (defined in section (n)(16.0)) of a specific component or system if deterioration or failure of such would not cause the vehicle's emissions to exceed the emission threshold.
(1.6) After the 1998 model year, for Non-LEVs, fulfillment of federal On-Board Diagnostic (OBD) requirements shall be deemed to be an acceptable option for the manufacturer for the purpose of meeting these requirements.
(1.7) For 1994 and 1995 model years only, illumination of the malfunction indicator light upon detection of a malfunction shall be optional for catalyst, misfire, and complete evaporative system monitoring. MIL illumination for such vehicles shall be optional for other monitoring requirements, subject to Executive Officer approval, on the basis of use of a new monitoring strategy which is significantly different than that used previously by the manufacturer and/or which entails a high degree of sophistication in its application. Irrespective of the preceeding the MIL shall illuminate on these vehicles in accordance with section 1968.1 for lack of function (see section (n)(16.0)) for electronic components/systems otherwise approved for not illuminating the MIL. Furthermore, setting fault codes for all malfunctions shall continue to conform with requirements of section 1968.1. For components/systems not requiring illumination of the MIL, manufacturers shall provide a plan for approval by the Executive Officer for reporting on the correct performance of the monitoring systems in customer use at 6 month intervals beginning from the start of production each year for at least the first three years after production. Approval of the plan shall be based on obtaining a statistically valid sample size, assuring that adequate resources are available to investigate the potential problems, and assuring that a wide variety of vehicles, operating modes, and mileage accumulation will be included in the evaluation. Should incorrect performance of the diagnostic system be determined by the Executive Officer on the basis of these reports or through other means, manufacturers shall recall the vehicles for correction of the OBD II system in accordance with Article 2.2. Title 13 CCR, or they shall submit an alternate plan for remedying the problem for approval by the Executive Officer on the basis of achieving comparable capture rates and timeliness as an official recall plan.
(1.8) Manufacturers may employ alternate statistical MIL illumination and fault code storage protocols to those specified in these requirements, subject to Executive Officer approval based on comparable timeliness in detecting a malfunction and evaluating system performance. For strategies requiring on average between three and six driving cycles for MIL illumination, the manufacturer shall provide data and/or an engineering evaluation which adequately demonstrate that the monitoring system is equally effective and timely in detecting component deterioration. Strategies requiring on average more than six driving cycles for MIL illumination shall not be accepted.
(1.9) Regarding diagnostic system monitoring conditions and MIL illumination requirements, manufacturers are generally required to define appropriate operating conditions for monitoring, subject to the limitation that the monitoring conditions shall be encountered at least once during the first engine start portion of the applicable Federal Test Procedure (FTP) test. Alternatively, manufacturers may request, subject to Executive Officer approval, use of monitoring conditions encountered during the Unified Cycle (see section (n)). In approval of the request, the Executive Officer shall consider the extent to which use of the cycle provides for more effective monitoring. Upon detection of a malfunction, the MIL is to be illuminated and a fault code stored no later than the end of the next driving cycle during which monitoring occurs provided the malfunction is again detected. Until the 1997 model year, diagnostic strategies that illuminate the MIL on the basis of completing a trip (trip is defined in section (n)(5.0) of these requirements) shall be accepted. The Executive Officer shall accept trip based diagnostic systems until the 1998 model year, provided the manufacturer adequately demonstrates that the diagnostic strategies run with reasonable frequency during normal driving conditions. When a trip criterion is employed, upon detection of a malfunction, the diagnostic system shall store a fault code and the MIL shall be illuminated no later than the end of the next trip if the malfunction is again present.
(1.10) For other emission control devices not identified or addressed in sections (b)(1) through (b)(12) (e.g., hydrocarbon adsorbers), manufacturers shall submit a plan for Executive Officer approval of the monitoring strategy and fault thresholds prior to introduction on a production vehicle. Executive Officer approval shall be based on the effectiveness of the monitoring strategy, the malfunction criteria utilized, and the monitoring conditions required by the diagnostic.
(2.0) Manufacturers may request Executive Officer approval to disable a diagnostic system designed to meet the requirements of section (b) at ambient engine starting temperatures below twenty degrees Fahrenheit (low ambient temperature conditions may be determined based on intake air or engine coolant temperature at engine starting), and at elevations above eight thousand feet above sea level provided the manufacturer submits data and/or an engineering evaluation which adequately demonstrate that monitoring would be unreliable when such conditions exist. Notwithstanding, diagnostic system disablement may be requested at other ambient engine starting temperatures if the manufacturer adequately demonstrates with data and/or an engineering evaluation that misdiagnosis would occur due to the impact of such ambient temperatures on the performance of the component itself (e.g., component freezing).
(2.1) Manufacturers may disable monitoring systems that can be affected by running out of fuel (e.g., misfire detection) when the fuel level is low, provided disablement will not occur when the fuel level is above 15 percent of the nominal capacity of the fuel tank.
(2.2) For vehicles designed to accommodate the installation of Power Take-Off (PTO) units (defined in section (n)(19.0)), disablement of affected monitoring systems is permitted provided disablement occurs only while the PTO unit is active, and provided the OBD II readiness code (specified in section (e)) is cleared by the on-board computer (i.e., all bits shall be set to "test not complete") while the PTO unit is activated. The code may be restored to its state prior to PTO activation upon PTO de-activation.
(b) MONITORING REQUIREMENTS
(1.0) CATALYST MONITORING
(1.1) Requirement:
(1.1.1) The diagnostic system shall monitor the catalyst system for proper performance.
(1.1.2) Manufacturers are not required to implement these catalyst monitoring requirements on diesel vehicles and engines. Further, manufacturers of spark-ignited lean-burn vehicles and engines may request that the Executive Officer exempt such applications from these catalyst monitoring requirements if it can be demonstrated that a reliable monitoring technology is not available. The Executive Officer shall approve such a request upon determining that all reasonable monitoring technologies have been considered to the extent possible.
(1.2) Malfunction Criteria:
(1.2.1) Low Emission Vehicles (see section (n)(14.0)): The catalyst system shall be considered malfunctioning when its conversion capability decreases to the point that either of the following occurs: 1) Hydrocarbon (HC) emissions exceed the applicable emission threshold specified in section (b)(1.2.2) below, or 2) the average Federal Test Procedure (FTP) Non-Methane Hydrocarbon (NMHC) conversion efficiency of the monitored portion of the catalyst system falls below 50 percent. Regarding the first criterion, the malfunction threshold shall be based on the emission standards to which the vehicle is certified. For low emission vehicle applications, hydrocarbon emissions shall be multiplied by the certification reactivity adjustment factor for the vehicle. Regarding the second criterion, the efficiency determination shall be based on an FTP test wherein a malfunction is noted when the cumulative NMHC emissions measured at the outlet of the monitored catalyst(s) are more than 50 percent of the cumulative engine-out emissions measured at the inlet of the catalyst(s).
(1.2.2) TLEV applications shall employ an emission threshold malfunction criterion of 2.0 times the applicable FTP HC standard plus the emissions from a test run with a representative 4000 mile catalyst system (125 hours of operation for medium-duty vehicles with engines certified on an engine dynamometer). The emission threshold criterion for LEV and ULEV applications shall be 2.5 and 3.0 times the applicable FTP HC standard, respectively, plus the emission level with a representative 4000 mile catalyst system. Notwithstanding, beginning with the 1998 model year, manufacturers shall phase in an emission threshold of 1.75 times the applicable FTP HC standard for all categories of low emission vehicles, which shall not include the emission level with a 4000 mile catalyst system. The phase in percentages (based on the manufacturer's projected sales volume for low emission vehicle applications) shall equal or exceed 20 percent in the 1998 model year, 40 percent in the 1999 model year, 60 percent in the 2000 model year, 80 percent in the 2001 model year, with 100 percent implementation for the 2002 model year. Alternate phase-in schedules that provide for equivalent emission reduction and timelines overall as defined in section (n)(21.0) shall be accepted. Small volume manufacturers shall not be required to meet the phase-in percentages; however, such manufacturers shall achieve 100 percent compliance by the 2002 model year.
(1.2.3) Non-Low Emission Vehicles: The catalyst system shall be considered malfunctioning when its conversion capability decreases to the point that HC emissions increase by more than 1.5 times the standard over an FTP test from a test run with a representative 4000 mile catalyst system.
(1.2.4) For 1994 and 1995 model year vehicles and engines, as an option to monitoring the catalyst during FTP driving conditions, manufacturers may monitor the front catalyst independently of, or in combination with, the next catalyst downstream. Each monitored catalyst or catalyst combination shall be considered malfunctioning when total HC conversion efficiency falls below 60 percent while in normal closed loop operation. As a guideline, the catalyst(s) should not be considered malfunctioning when its efficiency is greater than 80 percent. The efficiency determination shall be based on a steady state test wherein a malfunction is noted when the total HC emission concentration measured at the outlet of the monitored catalyst(s) is more than 20 to 40 percent of the cumulative total engine-out emissions measured at the inlet of the catalyst(s). Alternatively, if correlation with FTP emissions can be demonstrated, manufacturers may use the malfunction criteria specified in (b)(1.2.1) or (b)(1.2.3). 1994 and 1995 model year vehicles certified to this option shall incorporate FTP based monitoring no later than the 1997 model year (vehicles initially complying with section 1968.1 in the 1996 model year shall utilize an FTP based catalyst monitoring system).
(1.3) Monitoring Conditions:
(1.3.1) The manufacturer shall define appropriate operating conditions during which monitoring shall occur, subject to the limitation that the monitoring conditions shall be encountered at least once during the first engine start portion of the applicable FTP test. However, vehicles utilizing steady state monitoring (as permitted by section (1.2.4) above), may alternatively comply with the monitoring conditions specified in section (1.3.2). The monitoring system shall operate at least once per driving cycle during which the manufacturer-defined monitoring conditions are met.
(1.3.2) If steady state efficiency is being monitored (see section (b)(1.2.4)), the manufacturer shall choose a non-closed throttle, reasonably steady speed condition for monitoring the catalyst with the constraints that the check shall (i) occur between 20 mph and 50 mph, or within an engine rpm and torque range determined by the manufacturer to be representative of medium-duty vehicle operating conditions between 20 and 50 mph steady speed conditions with a load equivalent to 50 percent of the maximum load carrying capacity, (ii) take no more than a 20 second interval to determine both that the vehicle is operating in a proper window to perform the check and to actually perform the check, and (iii) be conducted at the earliest such condition encountered after the beginning of closed-loop operation for each driving cycle. Performance of the check may be delayed after engineer startup until stabilized coolant temperature is achieved and/or a suitable cumulative time interval of non-closed throttle vehicle operation has elapsed to ensure the catalyst is warmed-up for properly performing the monitoring check. The specified cumulative time interval shall begin from the first non-closed throttle operation after achieving a stabilized coolant temperature or after engine starting and shall not exceed 180 seconds. These monitoring constraints and conditions may be altered, subject to Executive Officer Approval. Such approval shall be granted if the manufacturer submits data and an engineering evaluation justifying the need for the exception and demonstrates that the requested alteration would yield improved catalyst monitoring. "Reasonably steady" speed interval in this instance means a 20 second period where all accelerations and decelerations are of an average magnitude equivalent to 0.5 mph/second or less over any two second interval during this period. The manufacturer may abort the check if engine operating conditions change during the check so that the vehicle exceeds the speed or acceleration/deceleration tolerance before the end of the checking interval. The manufacturer may base performance of the catalyst check upon engine RPM and loan conditions equivalent to the above monitoring conditions. If a manufacturer develops a means of monitoring catalyst efficiency which cannot utilize a steady state monitoring period (e.g., examining time vs. temperature during catalyst warmup), it may present a monitoring proposal to the Executive Officer for approval based on equivalent accuracy and timeliness as the steady state monitoring protocol in detecting a malfunctioning catalyst.
(1.4) MIL Illumination and Fault Code Storage:
(1.4.1) Except as noted below, upon detection of a catalyst malfunction, the MIL shall illuminate and a fault code stored no later than the end of the next driving cycle during which monitoring occurs provided the malfunction is again present.
(1.4.2) For steady state catalyst efficiency checks, upon detection of catalyst efficiency below 60 percent, the diagnostic system may perform up to two successive monitoring checks prior to informing the vehicle operator of a malfunction. These monitoring checks need not occur on the same driving cycle, but shall be performed as soon as proper monitoring conditions occur. If catalyst efficiency remains below 60 percent for the three sequential checks, a fault code shall be stored and the MIL shall then be activated.
(1.4.3) The diagnostic system shall temporarily disable catalyst monitoring when a malfunction exists which could affect the proper evaluation of catalyst efficiency.
(1.4.4) The monitoring method for the catalyst(s) shall be capable of detecting when a catalyst trouble code has been cleared (except diagnostic system self-clearing), but the catalyst has not been replaced (e.g., catalyst over temperature approaches may not be acceptable).
(2.0) HEATED CATALYST MONITORING
(2.1) Requirement:
(2.1.1) The diagnostic system shall monitor all heated catalyst systems for proper heating.
(2.1.2) The efficiency of heated catalysts shall be monitored in conjunction with the requirements of section (b)(1).
(2.2) Malfunction Criteria:
(2.2.1) The catalyst heating system shall be considered malfunctioning when the catalyst does not reach its designated heating temperature within a requisite time period after engine starting. The time period is to be determined by the manufacturer subject to the requirement that the system shall detect a heating system malfunction causing emissions from a vehicle equipped with the heated catalyst system to exceed 1.5 times any of the applicable FTP standards.
(2.2.2) Manufacturers using other heating or monitoring strategies may submit an alternate plan for approval by the Executive Officer to monitor heated catalyst systems based on comparable reliability and timeliness to these requirements in detecting a catalyst heating malfunction.
(2.3) Monitoring Conditions:
Manufacturers shall define appropriate operating conditions for monitoring of the catalyst heating system, subject to the limitation that the monitoring conditions shall be encountered at least once during the first engine start portion of the applicable FTP test. The monitoring system shall operate at least once per driving cycle during which the manufacturer-defined monitoring conditions are met.
(2.4) MIL Illumination and Fault Code Storage:
Upon detection of a catalyst heating malfunction, the MIL shall illuminate and a fault code stored no later than the end of the next driving cycle during which monitoring occurs provided the malfunction is again present.
(3.0) MISFIRE MONITORING
(3.1) Requirement: The diagnostic system shall monitor engine misfire and shall identify the specific cylinder experiencing misfire. Manufacturers may request Executive Officer approval to store a general misfire fault code instead of a cylinder specific code under certain operating conditions provided the manufacturer submits data and/or an engineering evaluation which adequately demonstrate that the misfiring cylinder cannot be reliably identified when such conditions occur. If more than one cylinder is misfiring, a separate code shall indicate that multiple cylinders are misfiring (specifying the individual misfiring cylinders under this condition is optional, however, identifying only one misfiring cylinder shall not occur when a multiple misfire code is stored).
(3.2) Malfunction Criteria: The manufacturer shall specify in the documentation provided for certification (see subsection (g) and (h) infra.) a percentage of misfires out of the total number of firing events necessary for determining a malfunction for each of the conditions listed below.
(A) The percent misfire evaluated in 200 revolution increments for each engine speed and load condition which would result in catalyst damage. Subject to Executive Officer approval, a longer interval may be employed (but only for determining, on a given driving cycle, the first misfire exceedance in section (3.4.1)(A) below) provided the manufacturer submits data and/or an engineering evaluation which adequately demonstrate that catalyst damage would not occur due to unacceptably high catalyst temperatures before the interval has elapsed. The manufacturer shall submit in the certification documentation catalyst temperature data versus percent misfire over the full range of engine speed and load conditions. The data shall be obtained from a representative cross section of a manufacturer's engine offerings from small to large displacements. Up to three such engine evaluations shall be documented per manufacturer, though a manufacturer may submit more data if desired. An engineering evaluation shall be provided for establishing malfunction criteria for the remainder of engine families in the manufacturer's product line. The Executive Officer shall waive the evaluation requirement each year if, in the judgment of the Executive Officer, technological changes do not affect the previously determined malfunction criteria;
(B) The percent misfire evaluated in 1000 revolution increments which would cause emissions from a durability demonstration vehicle to exceed 1.5 times any of the applicable FTP standards if the degree of misfire were present from the beginning of the test. Subject to Executive Officer approval, a manufacturer may employ other revolution increments if the manufacturer adequately demonstrates that the strategy is equally effective and timely in detecting misfire. For the purpose of establishing the percent misfire, the manufacturer shall conduct the demonstration test(s) with misfire events occurring at equally spaced complete engine cycle intervals, across randomly selected cylinders throughout each 1000 revolution increment. However, the percent misfire established shall be applicable for any misfire condition (e.g. random, continuous, equally spaced, etc.) for the purpose of identifying a malfunction. This criterion may be used for all vehicles with engines containing the same number of cylinders as the demonstration vehicle. The number of misfires in 1000 revolution increments which was determined for the durability demonstration vehicle malfunction criterion may be used to establish the corresponding percent misfire malfunction criteria for engines with other numbers of cylinders. The malfunction criteria for a manufacturer's product line shall be updated when a new durability demonstration vehicle is tested which indicates more stringent criteria are necessary than previously established to remain within the above emission limit;
(3.3) Monitoring Conditions:
(3.3.1) Pre-1997 Model Year Vehicles: misfire shall be monitored continuously during, at a minimum, positive torque operating conditions within the range of engine speed and load condition combinations encountered during an FTP test; nonetheless, subject to Executive Officer approval, manufacturers may employ higher misfire percentage malfunction criteria under specific conditions within the range of operating conditions encountered during an FTP test if the manufacturer provides data and/or an engineering evaluation which adequately demonstrate that the detection of lower levels of misfire would not be reliable for the vehicle model in question when such conditions are encountered without making fundamental engine of control unit design modifications. If the manufacturer can so demonstrate that even the detection of a higher misfire percentages is not feasible under specific FTP operating conditions, the manufacturer may request Executive Officer approval to disable the monitoring system when such conditions are encountered.
(3.3.2) 1997 and Later Model Year Vehicles: Manufacturers shall phase in expanded misfire monitoring conditions beginning with the 1997 model year. The phase in percentages (based on the manufacturer's projected sales volume for all vehicles and engines) shall equal or exceed 50 percent in the 1997 through 1999 model years, 75 percent in the 2000 model year, 90 percent in the 2001 model year, with 100 percent implementation for the 2002 model year. Alternate phase-in schedules that provide for equivalent emission reduction and timeliness overall shall be accepted. Small volume manufacturers shall not be required to meet the phase-in percentages; however, 100 percent implementation of these monitoring conditions shall be required beginning with the 2002 model year. On vehicles meeting these phase-in percentages, except as provided for in section (3.3.3) below, monitoring for misfire shall be continuous from engine starting (see section (n)) and under all positive torque engine speeds and load conditions. Vehicles not meeting the monitoring conditions of this section shall meet the monitoring conditions specified in section (b)(3.3.1) above.
(3.3.3) As an exception to monitoring misfire during all positive torque operating conditions, manufacturers may disable misfire monitoring in the engine operating region bound by the positive torque line (i.e., engine load with the transmission in neutral), and the two following engine operating points: an engine speed of 3000 rpm with the engine load at the positive torque line, and the redline engine speed (defined in section (n)(18.0)) with the engine's manifold vacuum at four inches of mercury lower than that at the positive torque line. Misfire detection systems unable to detect all misfire patterns under all required conditions shall be evaluated for compliance by the Executive Officer based on, but not limited to, 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 shall 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. Further, with Executive Officer approval, the manufacturer may disable misfire monitoring or employ higher malfunction criteria when misfire cannot be distinguished from other effects (e.g., rough roads, transmission shifts, etc.) when using the best available monitoring technology. The manufacturer shall present data and/or an engineering evaluation to the Executive Officer to justify the proposed action. Executive Officer approval shall be based on the extent to which monitoring is expected to be disabled in relation to the capabilities of the best available monitoring technologies as applied to other engines. However, through the 2000 model year, any such disablement occurring within the first 5 seconds after engine starting shall not require Executive Officer approval. Additionally, for engines with greater than eight cylinders, the Executive Officer shall waive the requirements of this section provided the manufacturer submits data and/or an engineering evaluation which adequately demonstrates 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, but under no circumstances shall acceptance be granted for misfire detection systems not meeting the requirements of section (b)(3.3.1) above.
Figure 10
(3.4) MIL Illumination with Fault Code Storage:
(3.4.1) Upon detection of the level of misfire specified in subsection (3.2)(A), the following criteria shall apply for MIL illumination and fault code storage:
(A) A temporary fault code shall be stored and the MIL shall blink once per second during actual misfire conditions no later than after the third exceedance of the specified misfire level when operating in the region bound by the maximum engine speed and load conditions encountered during the FTP cycle and no later than after the first exceedance of the specified misfire level when operating at any other engine speed and load condition during a single driving cycle. While a temporary fault code is stored, the MIL shall blink during every subsequent exceedance during the driving cycle but may remain extinguished when misfire is not present. If the level of misfire is exceeded again (a single exceedance) during the following driving cycle or the next driving cycle in which similar conditions are encountered (as defined in section (3.4.3) or while a temporary fault code for the level of misfire specified in subsection (3.2)(B) is present, the MIL shall blink as specified above, a fault code shall be stored, and the MIL shall remain continuously illuminated, even if the misfire ceases. The initial temporary code and stored conditions may be erased if misfire is not detected during the following driving cycle and similar conditions have been encountered without an exceedance of the specified misfire level. The code and conditions may also be erased if similar driving conditions are not encountered during 80 driving cycles subsequent to the initial detection of a malfunction.
(B) Notwithstanding, in vehicles which provide fuel shutoff and default fuel control to prevent overfueling during misfire conditions, the MIL need not blink. Instead, the MIL may illuminate continuously in accordance with the requirements for continuous MIL illumination in section (3.4.1)(A) above upon detection of misfire provided that the fuel shutoff and default control shall be activated as soon as misfire is detected. Fuel shutoff and default fuel control may be deactivated only to permit fueling outside of the misfire range.
(3.4.2) Upon detection of the misfire levels specified in subsection (3.2)(B), the following criteria shall apply for MIL illumination and fault code storage:
(A) A temporary fault code shall be stored no later than after the fourth exceedance of the specified misfire level during a single driving cycle and the MIL shall be illuminated and a fault code stored no later than the end of the following driving cycle or the next driving cycle in which similar conditions are encountered (as defined in section (3.4.3)) if the level of misfire is again exceeded four times. The initial temporary code and stored conditions may be erased if misfire is not detected during the following driving cycle and similar conditions have been encountered without an exceedance of the specified misfire level. The code and conditions may also be erased if similar driving conditions are not encountered during 80 driving cycles subsequent to the initial detection of a malfunction.
(B) Notwithstanding, a temporary fault code shall be stored no later than after the first exceedance of the specified misfire level during a single driving cycle if the exceedance occurs within the first 1000 revolutions from engine start (defined in section (n)(20.0)) during which misfire detection is active. The MIL shall be illuminated and a fault code stored no later than the end of any subsequent driving cycle if misfire is again detected in the first 1000 revolutions. If similar conditions are encountered during a subsequent driving cycle without an exceedance of the specified misfire level, the initial temporary code and stored conditions may be erased. Furthermore, if similar driving conditions are not encountered during 80 driving cycles subsequent to the initial detection of a malfunction, the initial temporary code and stored conditions may be erased.
(3.4.3) Upon detection of misfire, manufacturers shall store the engine speed, load, and warm-up status (i.e., cold or warmed-up) under which the first misfire event which resulted in the storage of a temporary fault code was detected. A driving cycle shall be considered to have similar conditions if the stored engine speed conditions are encountered within 375 rpm, load conditions within 20 percent, and the same warm-up status is present. With Executive Officer approval, other strategies for determining if similar conditions have been encountered may be employed. Approval shall be based on comparable timeliness and reliability in detecting similar conditions.
(3.5) MISFIRE MONITORING FOR DIESELS
(3.5.1) Requirement: Beginning with the 1998 model year, the diagnostic system on a diesel engine shall be capable of detecting the lack of combustion in one or more cylinders. To the extent possible without adding hardware for this specific purpose, the diagnostic system shall also identify the specific cylinder for which combustion cannot be detected. If the lack of combustion is present in more than one cylinder, a separate code shall indicate that multiple cylinders are malfunctioning (specifying the individual malfunctioning cylinders under this condition is optional; however, identifying one malfunctioning cylinder shall not occur when a multiple cylinder code is stored).
(3.5.2) Malfunction Criteria: A cylinder shall be considered malfunctioning when combustion cannot be detected.
(3.5.3) Monitoring Conditions: Manufacturers shall define appropriate operating conditions for monitoring, subject to the limitation that the monitoring conditions shall be encountered at least once during the first engine start portion of the applicable FTP test. The monitoring system shall operate at least once per driving cycle during which the manufacturer-defined monitoring conditions are met.
(3.5.4) MIL Illumination and Fault Code Storage: The MIL shall illuminate and a fault code shall be stored no later than the end of the next driving cycle during which monitoring occurs provided the malfunction is again present.
(4.0) EVAPORATIVE SYSTEM MONITORING
(4.1) Requirement:
(4.1.1) The diagnostic system shall verify air flow from the complete evaporative system. In addition, the diagnostic system shall also monitor the evaporative system for the loss of HC vapor into the atmosphere by performing a pressure or vacuum check of the complete evaporative system.
(4.1.2) Manufacturers may temporarily disable the evaporative purge system to perform a check.
(4.1.3) Manufacturers may request Executive Officer approval to abort an evaporative system check under specific conditions (e.g., when the fuel tank level is over 85 percent of nominal tank capacity) if data and/or an engineering evaluation are provided which adequately demonstrate that a reliable check cannot be made when these conditions exist.
(4.1.4) Subject to Executive Officer approval, other monitoring strategies may be used provided the manufacturer provides a description of the strategy and supporting data showing equivalent monitoring reliability and timeliness in detecting an evaporative system malfunction or leak.
(4.1.5) Implementation of this requirement is mandatory only for 1996 and later model year vehicles designed to comply with the requirements of Title 13, California Code of Regulations, Section 1976, "Standards and Test Procedures for Motor Vehicle Fuel Evaporative Emissions," for 1995 and subsequent model year vehicles.
(4.2) Malfunction Criteria:
(4.2.1) An evaporative system shall be considered malfunctioning when no air flow from the system can be detected, or when a system leak is detected that is greater than or equal in magnitude to a leak caused by a 0.040 inch diameter orifice in any portion of the evaporative system excluding the tubing and connections between the purge valve and the intake manifold.
(4.2.2) Beginning with the 2000 model year, manufacturers shall phase-in diagnostic strategies to detect system leaks greater than or equal in magnitude to a leak caused by a 0.020 inch diameter orifice. The phase-in percentages (based on the manufacturer's projected sales volume for all vehicles) shall equal or exceed 20 percent for the 2000 model year, 40 percent for the 2001 model year, 70 percent for the 2002 model year, and 100 percent implementation for the 2003 model year. Alternate phase-in schedules that provide for equivalent emission reduction and timeliness overall shall be accepted. Small volume manufacturers shall not be subject to the phase-in requirements; however, 100 percent implementation shall be required for the 2003 model year.
(4.2.3) On vehicles with fuel tank capacity greater than 25 gallons, the Executive Officer shall revise the size of the orifice if the most reliable monitoring method available cannot reliably detect a system leak of the magnitudes indicated above. Further, on vehicles with fuel tank capacity from 18 to 25 gallons, the Executive Officer may allow a larger size orifice (e.g., 0.050 inch diameter rather than 0.040 inch diameter) to be detected at low fuel levels (e.g., less than 50 percent of capacity) through the 1999 model year if the manufacturer demonstrates that it is necessary to avoid false MILs for a particular application due to a unique fuel tank configuration that would require hardware modifications to facilitate reliable monitoring.
(4.2.4) Upon request by the manufacturer and submission of data and/or engineering evaluation which adequately support the request, the Executive Officer shall revise the orifice size upward to exclude detection of leaks that cannot cause evaporative or running loss emissions to exceed 1.5 times the applicable standards.
(4.3) Monitoring Conditions: Manufacturers shall define appropriate operating conditions for monitoring, subject to the limitation that the monitoring conditions shall be encountered at least once during the first engine start portion of the applicable FTP test. The monitoring system shall operate at least once per driving cycle during which the manufacturer-defined monitoring conditions are met. However, monitoring conditions may be further limited with respect to detecting leaks equivalent to a 0.020 inch diameter orifice, subject to Executive Officer approval, on the basis that the monitoring conditions will be reasonably-occurring in-use, and provided that a check for leaks equal or greater in magnitude than a 0.040 inch orifice will continue to be conducted at least once per driving cycle as indicated above. Subject to Executive Officer approval, if performance of the check causes vehicles to exceed applicable emission standards when using the best available technology, manufacturers may perform evaporative system monitoring during a steady-speed condition, as defined in section (b)(1.3.2), between 20 and 50 mph.
(4.4) MIL Illumination and Fault Code Storage:
(4.4.1) Upon detection of an evaporative system malfunction or a malfunction that prevents completion of an evaporative system check, the MIL shall illuminate and a fault code shall be stored no later than the end of the next driving cycle during which monitoring occurs provided the malfunction is again present.
(4.4.2) If the diagnostic system is capable of discerning that a system leak is being caused by a missing or improperly secured fuel cap, the manufacturer may notify the vehicle operator through the use of an indicator light other than the MIL. The manufacturer is not required to store a fault code in this case. The indicator light shall conform to the requirements outlined in section (a)(1.1) for location and illumination. As another option, the manufacturer may extinguish the MIL, provided no other malfunctions have been detected, and may erase the fault code corresponding to the problem once the on-board diagnostic system has verified that the fuel cap specifically has been securely fastened. Other equivalent strategies shall be considered by the Executive Officer.
(5.0) SECONDARY AIR SYSTEM MONITORING
(5.1) Requirement: Any vehicle equipped with any form of secondary air delivery system shall have the diagnostic system monitor the proper functioning of (a) the secondary air delivery system and (b) any air switching valve.
(5.2) Malfunction Criteria:
(5.2.1) The diagnostic system shall indicate secondary air delivery system malfunction when the flow rate falls below the manufacturer's specified low flow limit such that a vehicle would exceed 1.5 times any of the applicable FTP emission standards.
(5.2.2) Manufacturers adequately demonstrating that deterioration of the flow distribution system is unlikely may request Executive Officer approval to perform only a functional check of the system. As part of this demonstration, manufacturers shall demonstrate that the materials used for the secondary air system (e.g., air hoses, and tubing) are inherently resistant to corrosion or other deterioration. If a functional check is approved, the diagnostic system shall indicate a malfunction when some degree of secondary airflow is not detectable in the exhaust system during a check.
(5.3) Monitoring Conditions: Manufacturers shall define appropriate operating conditions for monitoring of the secondary air system, subject to the limitation that the monitoring conditions shall be encountered at least once during the first engine start portion of the applicable FTP test. The monitoring system shall operate at least once per driving cycle during which the manufacturer-defined monitoring conditions are met.
(5.4) MIL Illumination and Fault Code Storage: The diagnostic system shall store a fault code and the MIL shall illuminate no later than the end of the next driving cycle during which monitoring occurs provided the malfunction is again present.
(6.0) AIR CONDITIONING SYSTEM REFRIGERANT MONITORING
(6.1) Requirement:
(6.1.1) The diagnostic system shall monitor air conditioning systems for loss of refrigerants which would harm the stratospheric ozone layer or are reactive in forming atmospheric ozone. Any sensor used for such monitoring shall itself be monitored for proper circuit continuity and proper range of operation. A provision for ensuring that a leak has been corrected before extinguishing the MIL shall be provided.
(6.1.2) Manufacturers of a model vehicle which will phase out the use of chlorofluorocarbons in its air conditioning systems by the 1996 model-year or which will use federally-approved refrigerants with substantially less atmospheric ozone depleting potential than CFC-12 need not comply with this requirement for that model.
(6.2) Malfunction Criteria: Manufacturers shall provide a monitoring strategy for approval by the Executive Officer for monitoring a refrigerant leak. The approval shall be based on timeliness and reliability in detecting a leak.
(6.3) Monitoring Conditions: Manufacturers shall define appropriate operating conditions for monitoring, subject to the limitation that the monitoring conditions shall be encountered at least once during the first engine start portion of the applicable FTP test. The monitoring system shall operate at least once per driving cycle during which the manufacturer-defined monitoring conditions are met.
(6.4) MIL Illumination and Fault Code Storage: The diagnostic system shall store a fault code and the MIL shall illuminate no later than the end of the next driving cycle during which monitoring occurs provided the malfunction is again present. The diagnostic system shall not clear a fault code and the MIL shall not turn off unless the leak has been corrected.
(7.0) FUEL SYSTEM MONITORING
(7.1) Requirement: The diagnostic system shall monitor the fuel delivery system for its ability to provide compliance with emission standards. For diesel vehiclesand engines, the manufacturer shall monitor the performance of all electronic fuel system components to the extent feasible with respect to the malfunction criteria specified in section (7.2) below. (continued)