Internal Control Module ROM Error

P0605 is an internal ROM (Read-Only Memory) checksum failure inside the PCM. This is typically a hard failure -- the PCM has lost its calibration. The fix is PCM replacement and programming at a dealer or with wiTECH. Before condemning the PCM, try a battery disconnect for 30 minutes. If the code immediately returns after keying on, the PCM is bad. Note: this module must be programmed to your VIN before the car will run. A generic parts search returns blank or donor units, so order it through a dealer or a rebuilder that programs to your VIN, or have a shop flash it after installation.

GM P0605 = 'Internal Control Module Read Only Memory Error.' Usually caused by a bad PCM flash or a failing PCM. Try reprogramming first with GM SPS if you have access. If reprogramming fails, replace the PCM and program it to the VIN. P0605 is NOT cleared by disconnecting the battery -- it requires programming intervention. Note: this module must be programmed to your VIN before the car will run. A generic parts search returns blank or donor units, so order it through a dealer or a rebuilder that programs to your VIN, or have a shop flash it after installation.

Ford P0605 indicates PCM ROM corruption. Most common cause is an interrupted FORScan or IDS flash. Try a full re-flash with FORScan Pro (requires a license) or visit a dealer. If the PCM won't take a flash after multiple attempts, the PCM is bricked and must be replaced. Motorcraft remanufactured PCMs come pre-flashed for your VIN if you provide it at order time. Note: this module must be programmed to your VIN before the car will run. A generic parts search returns blank or donor units, so order it through a dealer or a rebuilder that programs to your VIN, or have a shop flash it after installation.