Check Engine Light

All vehicles are equipped with a CHECK ENGINE light, located on instrument panel. Light comes on, as a bulb check, when ignition switch is turned to ON position and engine is not running. Light should not flash at this time and should go out when engine is started.

If CHECK ENGINE light remains on or flashes with engine running, self-diagnostic system has detected a problem. If problem goes away, light will go out after 10 seconds, but a fault code will be stored in ECM memory.

All trouble codes except for Code 41 (Ignition Signal Circuit) are stored in ECM memory. Code 41 is erased from memory as soon as ignition is turned off. In order to detect an active Code 41, connect a scan tester to ALDL diagnostic connector. Crank engine for 3 seconds, and leave ignition switch in ON position. If ignition switch is turned to OFF position, a present Code 41 will be lost.