What causes a P0631 code?

P0631 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a P0631 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0631 active.

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

OBD-II

P0631

P0631 VIN Not Programmed or Mismatch - TCM

What it means

The Transmission Control Module (TCM) does not have a programmed Vehicle Identification Number (VIN) or the stored VIN does not match the Engine Control Module (ECM) data.