42RLE Automatic Transmission

P0604-INTERNAL CONTROL MODULE RAM

For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


Theory of Operation


After the controller is reset, the microprocessor checks the integrity of each RAM location by writing to it and reading back from it. The read value should be the same as the written value. MIL on after 10 seconds of vehicle operation and transmission will be placed in limp-in.


- When Monitored:

One time after the ignition key is turned to the run position.

- Set Condition:

The read value does not match the written value in any RAM location.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.



Diagnostic Test


1. PCM - INTERNAL ERROR

If there are no possible causes remaining, view repair.

Repair

- Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. Check for Service Information Tune-ups or Service Bulletins for any possible causes that may apply. If no problems are found, replace and program the PCM. With the scan tool, perform QUICK LEARN.
- Perform 42RLE TRANSMISSION VERIFICATION TEST. 42RLE Transmission Verification Test