GM Automotive Error Code P1631: How to Fix It

Q: Can I drive my GM vehicle with P1631 error code?

No, P1631 prevents the engine from starting as it's a theft deterrent system fault. The vehicle will not start until this issue is resolved.

Q: How much does it cost to fix GM P1631 error code?

Repair costs vary from $100-200 for simple fixes like relearn procedures or wiring repairs, up to $800-1500 if BCM or PCM replacement is needed.

Q: Will disconnecting the battery fix P1631?

Disconnecting the battery may temporarily clear the code, but it won't fix the underlying issue. The code will return if the root cause isn't addressed.

Q: How long does the theft deterrent relearn take?

The complete relearn procedure typically takes 30-45 minutes, with each ON cycle requiring 10-15 minutes for the security light to turn off.

Q: Can a dead key fob battery cause P1631?

While a dead key fob battery can cause starting issues, P1631 specifically relates to communication between vehicle modules rather than the remote key fob system.

Abstract

GM error code P1631 indicates that your vehicle's theft deterrent system is receiving an incorrect start enable signal, preventing the engine from starting. This critical security-related fault typically involves communication issues between the body control module (BCM) and powertrain control module (PCM). The good news is that many P1631 issues can be resolved through proper diagnostic procedures and targeted repairs.