P0604 – Internal Control Module Random Access Memory (RAM) Error
- System
- ECM
- Dashboard light
- Check engine light (MIL)
- Check-engine blink code
- —
- Applies to
- Generic OBD-II meaning. Not every code is used by this car.
- Description
- Internal Control Module Random Access Memory (RAM) Error
- Detection / symptoms
- 1.Check engine light on
- Possible causes
- 1.Possible causes for this code include 2.PCM programming error 3.New or incorrect PCM 4.Aftermarket (high-performance) PCM program installed 5.Blown ECM/PCM fuse 6.Low battery voltage or complete battery discharge 7.Bad ECM/PCM power supply relay
- What to check
- 1.Check all battery and ECM power and earth connections first 2.Read every stored code; an ECM fault is rare, wiring faults are common 3.Have a specialist confirm before replacing the ECM
- Confidence
- medium (generic OBD-II definition, not checked against the factory manual for this car)
Generic OBD-II meaning (obd-codes.com), not checked against this car's factory manual. Clear the code and test-drive to confirm it returns. Search all fault codes · Common problems · Warning lights