Flow of Diagnosis

1. Verify the customer's concern by operating the turn signal/hazard flasher lamps to duplicate the condition.
2. Inspect to determine if one of the following mechanical or electrical concerns apply:

VISUAL INSPECTION CHART

Mechanical
- Damaged multi-function switch.

Electrical
- Circuitry open/shorted.
- Fuse junction panel fuses:
- 1 (10A)
- 3 (10A)
- 7 (15A)
- 13 (15A)
- 19 (10A)
- 20 (10A)
- 25 (10A)
- 31 (15A)
- Power distribution box Fuse 16 (20A)
- Bulb open.

3. If inspection reveals an obvious concern that is readily serviced, correct the concern before continuing with Inspection and Verification.
4. If a concern remains after the inspection, connect the Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent to the Data Link Connector (DLC) located beneath the instrument panel to perform DATA LINK DIAGNOSTICS test. If the NGS responds with NO RESPONSE/NOT EQUIPPED for the lighting control module, GO to Pinpoint Test CA. Test CA : No Communication With Lighting Control Module

If the DATA LINK DIAGNOSTICS test is passed for the lighting control module, retrieve continuous DTCs and execute Self Test Diagnostics for the lighting control module 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 (LCM) Diagnostic Trouble Code (DTC) Index to continue diagnostics.
7. If the lighting control module cannot be accessed by the NGS, go to Pinpoint Test CA. Test CA : No Communication With Lighting Control Module

Rotunda Service Bay Diagnostic System (SBDS (R)) 001-00001 may also be used to diagnose this system.