Diagnostic Strategy

Diagnostic Strategy

NOTE: Do not take short cuts or assume that critical adjustments have already been made.

Troubleshooting an electronically controlled automatic transaxle 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. Follow the procedures as written to avoid missing critical components or steps.

To correctly diagnose a concern, the technician should have the following publications available:
^ Computer and Control Systems
^ Technical Service Bulletins (TSBs)
^ Wiring Diagrams
^ Transmission Tester

These publications provide the information required when diagnosing transaxle concerns.

Use the Diagnostic Flow Chart as a guide and follow the steps indicated.

Preliminary Inspection
^ Know and understand the customer concern.
^ Verify the concern by operating the vehicle.
^ Check fluid level and condition.
^ Check non-factory add-on items.
^ Check shift linkages for correct adjustment.
^ Check TSBs for the concern.

Diagnostics
^ Carry out on-board diagnostic procedures; Key On/Engine Off (KOEO) and Key On/Engine Running (KOER).
^ Record all diagnostic trouble codes (DTCs).
^ Repair all non-transaxle codes, first.
^ Repair all transaxle codes second.
^ Erase all continuous codes and attempt to repeat them.
^ Repair all continuous codes.
^ If only pass codes, proceed to diagnosis by symptom charts for further information and diagnosis.

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