P0605

P0605 INTERNAL CONTROL MODULE ROM

Theory of Operation
After the controller is reset (ignition turned to the RUN position) 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 the program memory

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.

Possible Causes
- POWER OR GROUND CIRCUIT
- POWERTRAIN CONTROL MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

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 as necessary
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST-VER 1. Transmission Verification Test
No >> Replace the PCM. With the scan tool, perform QUICK LEARN.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST-VER 1. Transmission Verification Test