The powertrain control module (PCM) controls the fuel injector operation and the starter operation based on a vehicle theft deterrent (VTD) password from the instrument panel cluster (IPC). When the ignition is first turned ON, the IPC sends a programmed theft deterrent password to the PCM. The PCM acknowledges the password and responds to the IPC that normal fuel injector and starter operation will continue. If the PCM detects an incorrect password, a theft deterrent system failure, or an attempted vehicle theft, DTC 1631 will set. The engine will not start or crank as long as the condition is present.

The ignition is ON.

DTC P1631 indicates that the vehicle theft deterrent password that the PCM has learned does not agree with the password received from the VTD system. This condition can occur if an incorrect key is used when attempting to start the vehicle, or if the IPC has been replaced and the PCM Password Learn function has not been enabled. If the IPC has been replaced, the password must be relearned.

The numbers below refer to the step numbers on the diagnostic table.

2. Verifies if the condition for setting DTC B2710 or B2711 is current.

3. To set this code, the password that the PCM has learned does not agree with the password being received from the Body Control Module(BCM). This condition can occur if the VTD module has been replaced and the programming theft deterrent system compontent procedure has not been performed.