Flow of Diagnosis

1. Verify the customer's concern by operating the interior lamps (13776) to duplicate the condition.
2. Inspect to determine if one of the following electrical concerns apply:

VISUAL INSPECTION CHART

Electrical
^ Open fuse function panel Fuses 4 (10 A) and 15 (15 A): open Circuit breaker 12 (18 A).
^ Damaged miniature bulbs.
^ Circuitry open/shorted.
^ Connectors damaged/corroded.
^ Damaged interior lamps.
^ Damaged switches.
^ Stuck switches.

3. If the inspection reveals obvious concerns that can be readily serviced, correct the concern before continuing with Inspection and Verification.
4. If the concern(s) remains after the inspection, use Rotunda New Generation (NGS) Tester 007-00500 or equivalent connected to the data link connector (DLC) to retrieve continuous Diagnostic Trouble Codes (DTCs) and to execute Self Test Diagnostics for the lighting control module.
5. If self test is passed and no DTCs are retrieved, go to the Symptom Chart to continue diagnosis. Symptom Related Diagnostic Procedures
6. If DTCs are retrieved, go to Lighting Control Module (LCM) Diagnostic Trouble Code (DTC) Index to continue diagnosis. Diagnostic Trouble Code Tests and Associated Procedures
7. If the lighting control module cannot be accessed by the NGS, go to Pinpoint Test AA. AA No Comm With Lighting Control Module

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