Operation CHARM: Car repair manuals for everyone.

- Flow of Diagnosis - Start Here




Flow Of Diagnosis:





1. Get an accurate description of the complaint. Include filling out the DRIVEABILITY WORKSHEET and REPAIR HISTORY, refer to INFO TYPE/TECHNICAL/MANAGEMENT SUPPORT.
Visually check:
a. Vacuum hoses for splits, kinks, and proper routing.
b. Ignition wires for cracking, hardness, and proper connections at both the distributor and spark plugs.
c. All wiring for proper connections, pinches, and cuts.
d. Wiring harness for proper routing.
e. Check for missing components.

2. Check TSBs for manual updates, testing procedures, warranty and recall information.

3. Refer to PROM I.D. for latest updates and replacements, refer to COMPUTERIZED ENGINE CONTROLS/PROM I.D.


4. This step verifies that the on-board diagnostics are working.

5. If no trouble codes are stored and diagnostics are OK, continue with FLOW OF DIAGNOSIS.

6. If trouble codes are stored or the "SERVICE ENGINE SOON" (SES) lamp is inoperative, refer to COMPUTERIZED ENGINE CONTROLS for a complete diagnostic check.

7. If the engine starts OK or an intermittent problem exists, refer to DIAGNOSIS BY SYMPTOM.

8. Perform an ignition and fuel system check, refer to DIAGNOSTIC CHARTS/NO START OR STALL AFTER START.