P0601 Internal Control Module Memory Checksum Error
The OBD-II code P0601 is defined as the error of the control sum of the internal control module memory
The PCM or Power Train control module performs many important functions in a modern vehicle, such as fuel system management, ignition system, transmission, anti-lock braking system and traction control system. PCM regularly runs the self-diagnosis function, in which it performs normal mathematical calculations, and if the results of these calculations are not in line with expectations, a code such as the P0601 code will be set.
The P0601 code means that the PCM memory total test will fail. This is a routine self-test performed periodically throughout the day. This is crucial because the PCM memory modules store all the PCM operating system software as well as its short-term operational calculations. If this part of the PCM function is unreliable, the main drive unit computer can not be trusted to do exactly its job and may need to be replaced.
The most common reasons for the P0601 code are:
- ECU fault or malfunction
- Low voltage reaching the ECU
- Damaged wires
- Can be disturbed on the Can bus by other control modules
