Early Models

Flow of Diagnosis:

1. Get accurate description of complaint. Road test vehicle to verify. Perform underhood inspection.
VISUALLY CHECK:
Vacuum hoses for splits, kinks, and proper routing.
Ignition wiring for cracking, hardness, and proper connections at both the distributor and spark plugs.
All wiring for proper connections, pinches and cuts.
Wiring harness for proper routing.
Check for missing components.
2. Check TSB'S for manual updates, testing procedures, warranty and recall information.
3. Refer to ON-BOARD DIAGNOSTIC CHECK under TESTING PROCEDURES.
NOTE: The DRB II or an equivalent scan tool is required to extract fault codes.
4. Fault codes are codes that are stored by the ECU when a monitored circuit has a failure. Each code represents a problem or failure of a specific system, and is stored in the ECU memory so that they can be displayed to a technician for diagnosis. If, after performing On-Board Diagnosis, it has been determined that no codes have been stored and excessive emission levels still exist, then proceed to step 5.
5. See DIAGNOSIS BY SYMPTOM under TESTING PROCEDURES for symptom vehicle is exhibiting. Follow procedures as outlined for given symptom.