Flow of Diagnosis

1. Verify the customer's concern by operating the headlamp/autolamp system to duplicate the condition.

NOTE: If the headlamp switch loses power, the steering column/ignition/lighting control module will automatically default to the autolamp mode. With the ignition switch in RUN, the autolamp function will turn on the exterior lamps and the instrument panel lighting depending on the input of the light sensor amplifier as in normal operation, however the exist delay will be defaulted to the full three minutes.

2. Inspect to determine if one of the following electrical concerns apply:

VISUAL INSPECTION CHART

Electrical
- Circuitry open/shorted.
- Damaged light sensor amplifier.
- Damaged power distribution box Fuse 2 (15A), fuse junction panel Fuse 19 (10A), 26 (15A), 1 (10A), 25 (10A), 13 (15A), 7 (15A), 12 (15A) and 31 (10A).
- Damaged headlamp switch.
- Burned-out bulb.

3. If the inspection reveals obvious concern(s) that can be readily identified, service as required.
4. If the concern remains after inspection, connect the Rotunda New Generation Star (NGS) Tester to the Data Link Connector (DLC) located beneath the instrument panel to perform DATA LINK DIAGNOSTIC TEST. If the New Generation Star (NGS) Tester responds with NO RESPONSE/NOT EQUIPPED for Steering Column/Ignition/Lighting Control Module, go to Pinpoint Test AB. AB No Communication W/SCIL Control Module

If the DATA LINK DIAGNOSTIC TEST is passed for the Steering Column/Ignition/Lighting Control Module, retrieve continuous diagnostic trouble codes (DTCs) and execute Self Test Diagnostics for Steering Column/Ignition/Lighting Control Module.
5. If self test is passed and no diagnostic trouble codes are retrieved, go to the Symptom Chart to continue diagnostics. Symptom Chart(s)
6. If diagnostic trouble codes are retrieved, go to the Steering Column/Ignition/Lighting Control Module Diagnostic Trouble Code Index to continue diagnostics. SCIL Diagnostic Trouble Code (DTC) Index
7. If the Steering Column/Ignition/Lighting Control Module cannot be accessed by the New Generation Star tester, go to Pinpoint Test AB. AB No Communication W/SCIL Control Module