Chevrolet P1631: Theft Deterrent Start Enable Signal Not Correct

What Does The Chevrolet P1631 Code Mean?

This test checks for mismatched passwords between the body control module (BCM) and powertrain control module (PCM).

 

What Are The Symptoms Of The Chevrolet P1631 Code?

• The engine starts and then stalls immediately.
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The malfunction indicator light (MIL) will not illuminate.
• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

What Are The Potential Causes Of The Chevrolet P1631 Code?

• The PCM detects a wrong password from the BCM
• Fuel disable lockout is set
• The system has received an incorrect fuel continue password
• A faulty ignition switch
• The BCM was replaced

How Can You Fix The Chevrolet P1631 Code?

Inspect the engine harness for any damaged wires along the harness and repair if necessary.

Whenever replacing the BCM, PCM, follow the theft learn procedure in order for the system to learn the new password.

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Reference Sources

• GM, 2012, Service Bullettin – Malfunction Indicator Lamp (MIL) On, Various DTCs Set, IPC Inoperative, Display and/or BCM Fuse Blown.
• GM, 2013, Service Bullettin – Prior To Any Circuit Testing.
• GM, 2013, Service Bullettin – Malfunction Indicator Lamp (MIL) On, Various DTCs Set, IPC Inoperative, Display and/or BCM Fuse Blown.