68RFE Automatic Transmission

P0604-INTERNAL CONTROL MODULE RAM

For a complete wiring diagram Refer to Diagrams/Electrical.

Theory of Operation


After the controller is reset (ignition turned to the RUN position), the microprocessor checks the integrity of each RAM location by writing to it and reading back from it. The read value should be same as value written.


- When Monitored:
One time after the controller is reset (ignition turned to the RUN position).

- Set Condition:
Whenever the Transmission Control Module (TCM) detects an internal controller problem.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 68RFE - Pre-Diagnostic Troubleshooting Procedure


Diagnostic Test


1. CHECK WIRING AND CONNECTORS FOR INTERMITTENT OPERATION
Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits.
Wiggle the wires while checking for shorted and open circuits.
Check for any Service Bulletins that may apply.
Were there any problems found?

Yes


- Repair the power and/or ground circuits to the TCM as necessary.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test


No


- Replace the TCM. With the scan tool, perform Quick Learn.
- Perform 68RFE TRANSMISSION VERIFICATION TEST. 68RFE Transmission Verification Test