Initial Inspection and Diagnostic Overview

1. The interior lighting system is a Generic Electronic Module (GEM)/Central Timer Module (CTM) controlled system. Refer to Multifunction Electronic Control Module for additional information regarding GEM/CTM diagnostic strategies.
2. Verify the customer concern by operating the interior lamps.







VISUAL INSPECTION CHART

3. Visually inspect for obvious signs of mechanical and electrical damage.
4. If the concern remains after the inspection, connect the scan tool to the Data Link Connector (DLC) located beneath the instrument panel, and select the vehicle to be tested from the scan tool menu. If the scan tool does not communicate with the vehicle:
^ check that the program card is correctly installed.
^ check the connections to the vehicle.
^ check the ignition switch position.

5. If the scan tool still does not communicate with the vehicle, refer to the scan tool manufacturers manual.
6. Carry out the DATA LINK DIAGNOSTIC TEST. Pinpoint Test PC (Precheck)
If scan tool responds with:
^ CKT9I4, CKT9I5 or CKT7O = ALLECUS NO RESP/NOT EQUIP, refer to Module Communications Network(Information Bus).
^ NO RESP/NOT EQUIP for GEM/CTM, go to Pinpoint Test J. Test J: No Communication With the Module - GEM/CTM
^ NO RESP/NOT EQUIP for RAP, go to Pinpoint Test K. Test K: No Communication w/Remote Anti-Theft Personality Module
^ SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and perform self-test diagnostics for the GEM/CTM and the remote anti-theft personality (RAP) module.

7. If the DTCs retrieved are related to the concern, go to the GEM/CTM or RAP Module Diagnostic Trouble Code (DTC) Index. GEM/CTM Diagnostic Trouble Code (DTC) Index
8. If no DTCs related to the concern are retrieved, proceed to Symptom Chart - GEM/CTM. Symptom Related Diagnostic Procedures