Diagnostics

Diagnostics





Diagnosing electronically controlled automatic transmissions is simplified using the following procedures. It is important to remember that there is a definite procedure to follow. Do not take shortcuts or assume that critical checks or adjustments have already been made. Follow the procedures as written to avoid missing critical components or steps. By following the diagnostic sequence, the technician will be able to diagnose and repair the concern the first time.


On-Board Diagnostics with Scan Tool

NOTE: For detailed instruction and other diagnostic methods using the scan tool, refer to the scan tool tester and Computers and Control Systems Information.

These self-tests should be used to diagnose the PCM and should be carried out in order.

- Self Test - Key ON Engine OFF (KOEO)
- Self Test - Continuous Memory
- Self Test - Key ON Engine Running (KOER)
- PCM Reset Mode
- Clearing DTCs
- On-Board Diagnostic (OBD) Drive Cycle

For further information on other diagnostic testing features, refer to Computers and Control Systems Information.