Diagnostic Strategy

DESCRIPTION
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. 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.

To properly diagnose a concern, the technician should refer to:
- Automatic Transaxle/Testing and Inspection
- Powertrain Management/Testing and Inspection
- Technical Service Bulletins (TSB's)
- Electrical Diagrams
These provide the information required when diagnosing transaxle concerns. Using the Diagnostic Flow Chart as a guide, follow the steps as indicated. Diagnostic Flow Chart

PRELIMINARY INSPECTION
- Know and understand the customer's concern.
- Verify the concern by operating the vehicle.
- Check the fluid level and condition.
- Check for non-factory add-on items.
- Check shift linkages for proper adjustment.
- Check TSB's for the concern.

DIAGNOSTICS
- 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 for further information and diagnosis. [1][2]AX4N
- By following the diagnostic sequence the service technician will be able to diagnose and repair the concern the first time.