Tests W/Codes: Self-Diagnosis
When systems related to the emission controls malfunction during normal operation, a related trouble code will be stored in control unit memory.
- California - When a system fault occurs on California models, "CHECK ENGINE" light on dash will illuminate to inform driver a problem exists. Light will remain on until fault goes away or system is serviced. If fault goes away (system parameter returns to normal operation) before it is serviced, "CHECK ENGINE" light will go out; however, the related fault code will still remain in control unit memory until cleared. Stored codes may later be accessed and identified by counting flashes of the "CHECK ENGINE" light.
- Federal - As long as system fault is present, related code will be stored in control unit memory, even when ignition is turned off. Stored codes may later be accessed and identified by counting flashes of the "CHECK ENGINE" light. See Fig 1 . If fault goes away (system parameter returns to normal operation) before it is accessed or serviced, it will be erased from control unit memory.