P0604 - Internal Control Module Random Access Memory Error
- Low battery charge
- ECM power supply circuit is open or shorted
- ECM Programing
- Faulty ECM
- Engine may not start
The ECM continuously monitors its own internal memory status, internal circuits, and output signals transmitted to the throttle actuator. This self-check insures that the ECM is functioning properly. If any malfunction is detected, the will ECM will set the code and illuminate the engine light.