P0605
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.
| Possible Causes |
| PCM – INTERNAL ERROR |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. PCM – INTERNAL ERROR
Using the schematics as a guide, inspect the wiring and connectors. Repair as necessary. Pay particular attention to all power and ground circuits.
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 per
the Service Information. With the scan tool, perform QUICK LEARN.
- Perform 42RLE TRANSMISSION VERIFICATION TEST.