Powertrain Control Module (PCM)

P0605-INTERNAL CONTROL MODULE ROM

For a complete wiring diagram, refer to the Wiring Information. Electrical Diagrams

Theory of Operation

After the controller is reset, the microprocessor checks the integrity of the program memory (ROM). A checksum is calculated by adding all used bytes in the program memory. The sum should be the same as a known constant stored in memory. 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:
If the ROM checksum does not match a known constant.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure
PCM - INTERNAL ERROR

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