P0603 Internal Control Module Keep Alive Memory (KAM) Error
The engine computer lost its keep-alive memory.
Common causes
- Battery disconnected recently
- Poor battery or ground connection
- Internal module fault
Symptoms
- Check engine light
- Rough idle while adaptations relearn
What to check
- Check battery and grounds
- Clear and see if it returns
- Check for updates
Manufacturers may add their own detail to generic codes. If your vehicle shows a different description for P0603, follow the service information for that make and model.