Flow of Diagnosis

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. The on-board diagnostic check may be performed using the "CHECK ENGINE" lamp to display fault codes. Cycle the ignition switch on, off, on, off, on within five seconds and any fault codes stored in the memory will be displayed in a series of flashes representing digits. Lamp pauses approximately 4 seconds between codes.
4. If "CHECK ENGINE" light is on, or codes other than code 55 are stored (code 55 is an end of message code), you must refer to Computerized Engine Controls section. This step also checks to see that the on-board diagnostics are working. If after correcting problem excessive emission levels exist proceed to step 4.
5. Code 55 is an end of message code. If this is the only code stored, no fault codes are stored in memory.
6. See Diagnosis By Symptom under Testing Procedures for symptom vehicle is exhibiting. Follow procedures as outlined for given symptom.