Service Engine Soon Light

As a bulb and system check, SERVICE ENGINE SOON light glows 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 operate as described, malfunction has been detected in computerized engine control system or SERVICE ENGINE SOON light circuit is faulty.

To verify proper operation of SERVICE ENGINE SOON light on gasoline models, see DIAGNOSTIC CIRCUIT CHECK in BASIC TESTING article in this section. To verify proper operation of SERVICE ENGINE SOON light and retrieve trouble codes on diesel models, see DIAGNOSTIC SYSTEM CHECK chart under DIAGNOSTIC CHARTS in G - DIESEL TESTS W/ CODES article in this section.