P0604

P0604-INTERNAL CONTROL MODULE RAM

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.

Possible Causes
- PCM - INTERNAL ERROR

Always perform the 40/41TE Pre-Diagnostic Troubleshooting procedure before proceeding.

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.

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 the PCM. With the scan tool, perform QUICK LEARN.
Perform 40/41TE VERIFICATION TEST - VER 1 Transmission Verification Test