What P0601 means
Internal Control Module Memory Check Sum Error
How to diagnose
- Read freeze frame data. When P0601 set, your ECU snapshotted every sensor at that moment. This tells you what the car was doing when the fault triggered — RPM, load, coolant temp, throttle position, fuel trims. Almost always enough info to figure out the cause without further testing.
- Check for related codes. If you have P0601 plus other codes, fix the earliest one in the chain first — a single root cause often triggers multiple codes.
- Cheap fixes first. For most codes, the order is: inspect connectors + wiring (free), check for vacuum leaks (cheap), replace sensor (moderate), replace mechanical part (expensive). Follow that ladder before dropping money on parts.
Manufacturer-specific descriptions
Different manufacturers use P0601 for slightly different failure modes:
| AUDI | Lack of proper voltage to the PCM, Defective PCM memory module, Defective PCM ground circuit(s), Defective PCM controlled output devices |
| BMW | Internal Control Module Memory Check Sum Error |
| DODGE | Internal PCM Controller Failure |
| FIAT | EEPROM memory, |
| FORD | Internal Control Module Memory Check Sum Error |
| MITSUBISHI | Internal Control Module Memory Check Sum Error |
| NISSAN | Internal Control Module Memory Check Sum Error |
| VOLKSWAGEN | Control Module Read Only Memory (ROM) |
Read P0601 on your own car
DIY Fix My Car reads P0601 plus 25,000+ other DTC codes with manufacturer-specific descriptions. Includes freeze frame data, likely fix parts, and AI mechanic chat. Download free.