Initial Inspection and Diagnostic Overview

1. Verify the customer's concern by operating the system.
2. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart:

3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
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. Carry out the DATA LINK DIAGNOSTICS test using the scan tool. Pinpoint Test PC (Precheck) If the scan tool responds with:
^ CKT 914, CKT 915 or CKT 70 = ALL ECUS NO RESP/NOT EQUIP, refer to Module Communications Network (Information Bus).
^ NO RESP/NOT EQUIP for GEM, go to Multifunction Electronic Control Module (General Module).
^ System passed, retrieve and record the continuous Diagnostic Trouble Codes (DTCs), erase the continuous DTCs and carry out self test diagnostics for the GEM.
6. If the DTCs retrieved are related to the concern, go to GEM Diagnostic Trouble Code (DTC) Index. Diagnostic Trouble Code Tests and Associated Procedures
7. If no DTCs related to the concern are retrieved, go to the Symptom Chart to continue the diagnostics. Symptom Related Diagnostic Procedures