Strategy

Troubleshooting an electronically controlled automatic transmission is simplified by using the proven method of diagnosis. One of the most important things to remember is that there is a definite procedure to follow. Do not take short cuts or assume that critical checks or adjustments have already been made. Follow the procedures as written to avoid missing critical components or steps.
- Know and understand the customer's concern.
- Check the fluid level and condition.
- Verify the concern by operating the vehicle.
- Check for non-factory add-on items.
- Check shift linkages for proper adjustment.
- Check TSBs for the concern.
- Perform on-board diagnostic procedures (KOEO, KOER).
- Record all diagnostic trouble codes (DTCs).
- Repair all non-transmission codes FIRST.
- Repair all transmission codes SECOND.
- Erase all continuous codes and attempt to repeat them.
- Repair all continuous codes.
- If ONLY PASS codes are received, proceed to Diagnosis by Symptom Index. Diagnosis By Symptom Index

By following the diagnostic sequence, the technician will be able to diagnose and repair the concern the first time.