Initial Inspection and Diagnostic Overview

Inspection and Verification

CAUTION: Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not guarantee confirmation of a fault and may also cause additional faults in the vehicle being checked and/or the donor vehicle.

NOTE:
Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.
1 Verify the customer concern.
2 Visually inspect for obvious signs of mechanical or electrical faults.





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 Use the approved diagnostic system or a scan tool to retrieve any diagnostic trouble codes (DTCs) before moving onto the symptom chart or DTC index.
- Because the DTCs are stored in more than one module, a complete vehicle read is recommended
- Make sure that all DTCs are cleared following rectification

DTC index
For a complete list of all diagnostic trouble codes that could be logged on this vehicle, please refer to Vehicle / A L L Diagnostic Trouble Codes ( DTC ). For additional information, refer to Diagnostic Trouble Code (DTC) Index - DTC: Central Junction Box (BCM) Testing and Inspection