Flow of Diagnosis

1. Verify the customer's concern by operating the ignition switch to duplicate the condition.
2. Inspect to determine if one of the following mechanical or electrical concerns apply:
Mechanical
^ Damaged multi-function switch.
^ Damaged ignition switch.
Electrical
^ Circuitry open/shorted.
^ Open Fuse Junction Panel: Fuse 1 (15A) and Fuse 16 (15A), Circuit breaker 12 (18A) Power Distribution Box Fuse E (40A) and Fuse C (50A).

3. If inspection reveals an obvious concern that is readily serviced, correct the concern before continuing with Inspection and Verification.
4. If the concern remains after inspection, connect the Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent scan tool to the data link connector (DLC) located beneath the instrument panel to perform DATA LINK DIAGNOSTICS test. If the scan tool responds with NO RESPONSE/NOT EQUIPPED for the lighting control module, go to Pinpoint Test A. Test A: No Communication With Lighting Control Module
If the DATA LINK DIAGNOSTICS test is passed for the lighting control module(s), retrieve continuous DTCs and execute Self Test Diagnostics for the lighting control module(s) to retrieve current DTCs.
5. If self test is passed and no DTCs are retrieved, go to the Symptom Chart to continue diagnostics. Symptom Related Diagnostic Procedures
6. If DTCs are retrieved, go to the Lighting Control Module Diagnostic Trouble Code (DTC) Index to continue diagnostics. Testing and Inspection
7. If the lighting control module cannot be accessed by the scan tool, go to Pinpoint Test A. Test A: No Communication With Lighting Control Module