Diagnostic Strategy

Troubleshooting an 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.

To properly diagnose a concern, the technician should have the following publications available:

• Service Manual
• Powertrain Control/Emissions Diagnosis (PC/ED) Manual
• OASIS messages
• Technical Service Bulletins
• Electrical/Vacuum and Troubleshooting Manual (EVTM)

These publications provide the information required when diagnosing transmission concerns.

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