Inspection and Verification (Start Testing Here)

1. Verify the customer's concern by operating the headlamp/autolamp system to duplicate the condition.
2. Inspect to determine if one of the following electrical concerns apply:

VISUAL INSPECTION CHART

Electrical
- Power distribution box
- Fuse 16 (20A)
- Fuse 12 (40A)
- Fuse junction panel
- Fuse 3 (10A)
- Fuse 4 (10A)
- Fuse 5 (10A)
- Fuse 19 (10A)
- Fuse 20 (10A)
- Fuse 25 (10A)
- Loose connections.
- Corroded connections.
- Loose battery terminals.
- Corroded battery terminals.
- Discharged battery.
- Open lamp bulbs.
- Circuit concerns.
- Frayed wires
- Improper routing

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 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 AA. AA 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 Chart(s)
6. If DTCs are retrieved, go to the Lighting Control Module (LCM) Diagnostic Trouble Code (DTC) Index to continue diagnostics. LCM Diagnostic Trouble Code Index
7. If the lighting control module cannot be accessed by the New Generation Star (NGS) Tester, go to Pinpoint Test AA. AA No Communication With Lighting Control Module

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