Diagnostic Strategy: Notes
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.
NOTE:
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 correctly diagnose a concern, have the following publications available:
- INTRODUCTION - GASOLINE MODELS
- On-Line Automotive Service Information System (OASIS)
- TSBs
- SYSTEM WIRING DIAGRAMS - EXPEDITION , SYSTEM WIRING DIAGRAMS - EXPEDITION EL , SYSTEM WIRING DIAGRAMS - NAVIGATOR or SYSTEM WIRING DIAGRAMS - NAVIGATOR L article
These publications provide the information required when diagnosing transmission concerns.
Use the Diagnostic Flow Chart as a guide and follow the steps as indicated.