P0604 OBD II Trouble Code Internal Control Module Random Access Memory (RAM) Error
How to diagnose, repair, and info on what causes a P0604 trouble code which pertains to an internal RAM error in the powertrain control module. Also includes links to relevant forum topics on the code.
Symptoms of P0604 OBD II Trouble Code
- No start condition
- Multiple drivability issues
- Harsh or erratic automatic transmission shifting
- Diminished fuel economy
- ? The engine may stall or run roughly (especially at idle)
Common Causes of P0604 OBD II Trouble Code
- PCM programming error
- New or incorrect PCM
- Aftermarket (high-performance) PCM program installed
- Blown ECM/PCM fuse
- Low battery voltage or complete battery discharge
- Bad ECM/PCM power supply relay
- A defective ECM/PCM
- Open or shorted wiring or connectors in the CAN harness
- Insecure control module ground strap or broken ground wire
Severity of P0604 OBD II Trouble Code
Other internal control module error trouble codes include: