Diagnostic Process Overview

NOTE: During diagnosis, if the power supply is interrupted to the Powertrain Control Module (except PCM or vehicle battery disconnect) a PCM and Keep Alive Memory reset will occur. Refer to Powertrain Control Module (PCM) Reset, for additional information.

1. Understand and verify complaint.
2. Perform an audio, visual and manual inspection.
3. Perform normal maintenance as required. Verify production parts, or equivalent, were used for any maintenance.
4. Check for Technical Service Bulletins.
5. Localize the problem to the vehicle subsystem causing the symptom by using the Diagnostic Routines (Diagnosis by Symptom) flowcharts.
6. Isolate the root cause by following the pinpoint test steps in Computers and Control Systems.
7. Repair root cause.
8. Erase Diagnostic Trouble Codes (PCM reset) and reset Keep Alive Memory as instructed.
9. Verify that the vehicle is operating properly and the original complaint is eliminated.