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 damage.





3 If an obvious cause for an observed or reported condition is found, correct the cause (if possible) before proceeding to the symptom chart.
4 If the cause is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.

DTC Index
For a list of Diagnostic Trouble Codes (DTCs) that could be logged on this vehicle, please refer to A L L Diagnostic Trouble Codes ( DTC ). For additional information, refer to Diagnostic Trouble Code (DTC) Index - DTC: Engine Control Module 5.0L (PCM) Testing and Inspection