P0631 Fault Code

VIN Not Programmed or Mismatch - TCM

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0631 fault code signifies that the Transmission Control Module (TCM) has detected a VIN (Vehicle Identification Number) that either is not programmed or does not match the VIN stored within the module. This can lead to issues such as improper transmission operation or failure to recognize the vehicle's identity within the system.

What are the symptoms of the P0631 code?

Symptoms that may accompany this fault code include:

• Transmission shifting irregularities.
• Warning lights on the dashboard (such as check engine light).
• Loss of power to the engine due to transmission issues.
• Difficulty in engaging gears or transmission failure.

What causes the P0631 code?

Common causes of the P0631 code include:

• A newly installed TCM without proper programming.
• Corrupted data in the TCM from a previous fault or software update.
• A mismatch due to replacing components with used or unprogrammed parts.
• Faulty wiring or connections that affect communication between the TCM and other modules.

How to fix P0631?

To resolve the P0631 fault code, consider the following steps:

• Use a compatible scan tool to access the TCM and check for additional codes.
• Reprogram the TCM with the correct VIN using manufacturer-specific software.
• Inspect wiring and connectors for damage or short circuits.
• If necessary, replace the TCM with a new part and ensure it is programmed correctly.