Diagnostic Strategy

Diagnostic Strategy

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.

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:
^ Computers and Control Systems
^ OASIS Messages
^ Technical Service Bulletins (TSBs)
^ Wiring Diagrams

These publications provide the information required when diagnosing transaxle concerns.

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

Preliminary Inspection
^ Know and understand the customer's concern.
^ Verify the concern by operating the vehicle.
^ Check the fluid levels and condition.
^ Check for non-factory-installed items and verify correct installation
^ Check shift linkages for correct adjustment.
^ Check TSBs and OASIS messages regarding the concern.
^ Carry out quick tests, both KOER and KOEO.
^ Record all codes.

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 are obtained, proceed to Diagnosis By Symptom, for further information and diagnosis. 6 Speed Automatic Transaxle

Follow the diagnostic sequence to diagnose and repair the concern the first time.