Engine Control Module Diagnostic Ability

This portion of the basic inspection confirms that the ECM diagnostic system is functional and able to identify faults in the cruise control system. Turn ignition on. Place cruise control switch in ON position and ensure CRUISE indicator light on instrument cluster illuminates. Place cruise control switch in OFF position and ensure CRUISE indicator light on instrument cluster goes out. If CRUISE indicator light operates as described, perform Preliminary Diagnostic Trouble Code Check. See PRELIMINARY DIAGNOSTIC TROUBLE CODE CHECK . If CRUISE indicator light does not operate as described, diagnose CRUISE indicator light. See SYMPTOM INDEX  table under SYSTEM TESTS.