Initial Inspection and Diagnostic Overview

1. Verify the customer concern by duplicating the condition.
2. Visually inspect for obvious signs of mechanical and electrical damage.

Visual Inspection Chart:

3. If the concern remains after the inspection, connect 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 properly installed.
^ check the connections to the vehicle.
^ check the ignition switch position.
4. If scan tool still does not communicate with the vehicle, refer to the scan tool manual.
5. Carry out the DATA LINK DIAGNOSTIC TEST.
Pinpoint Test PC (Precheck)

If the scan tool responds with:
^ CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to Module Communications Network (Information Bus).
^ NO RESP/NOT EQUIP for PATS module, go to Pinpoint Test A. Test A: No Communication With Module
^ SYSTEM PASSED, retrieve and record the continuous DTCs, erase the continuous Diagnostic Trouble Codes (DTCs) and carry out self-test diagnostics for the PATS module.
6. If the DTCs retrieved are related to the concern, go to PATS DTC Index to continue diagnostics. PATS Diagnostic Trouble Code (DTC) Index
7. If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics. Symptom Related Diagnostic Procedures