California Code of Regulations › Title 13 - Motor Vehicles › Division 3 - Air Resources Board › Chapter 1 - Motor Vehicle Pollution Control Devices › Article 2 - Approval of Motor Vehicle Pollution Control Devices (New Vehicles) › Section 1968.1 - Malfunction and Diagnostic System Requirements-1994 and Subsequent Model-Year Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and Engines

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(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.