545RFE 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 (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 Powertrain Control Module (PCM) detects an internal controller problem.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. 45RFE/545RFE Pre-Diagnostic Troubleshooting Procedure


Diagnostic Test


1. CHECK WIRING AND CONNECTORS FOR INTERMITTENT OPERATION

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.


NOTE: Due to the integration of the Powertrain and Transmission Control Modules, the transmission part of the PCM has it's own specific 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 PCM and Transmission Control Relay as necessary.
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. 45RFE/545RFE Transmission Verification Test

No

- Replace the PCM. With the scan tool, perform QUICK LEARN. 45RFE/545RFE Transmission Verification Test
- Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. 45RFE/545RFE Transmission Verification Test