Service Engine Soon Light

As a bulb and system check, SERVICE ENGINE SOON light will glow when ignition switch is turned to ON position and engine is not running. When engine is started, light should go out. If light does not go out, a malfunction has been detected in the computerized engine control system or SERVICE ENGINE SOON light circuit is faulty. Light may be used on some models to display stored trouble codes. To access codes using "scan" or "non-scan" methods, see appropriate TESTS W/CODES article in this section.