P0601 Internal Control Module Memory Check Sum Error

P0601 points to an internal control module memory checksum error. The module has detected a problem validating stored memory data.

Code details

Generic OBD-II · P0

System: Computer
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace the PCM or ECM before proving the power, ground, voltage, and programming environment are correct.

Symptoms of P0601

Check-engine light, sometimes with several unrelated codes at once.
Warning lights, a no-start, or intermittent electrical faults.
Communication or module-reset problems on a scan tool.

Common causes of P0601

Low battery voltage, poor grounds, corroded connectors, or blown fuses.
Wiring or network (CAN bus) faults between modules.
A module software/programming issue, or rarely a failed controller.

Useful checks before replacing parts

Check battery condition, system voltage stability, grounds, power feeds, and module connectors before condemning the controller.
Review programming history, water intrusion, aftermarket electronics, and service bulletins for the vehicle.
Confirm the code returns after voltage and connector checks because controller replacement or reprogramming can be expensive.

Related OBD-II codes

These nearby computer entries can help compare wording and pin down the fault area.