Vehicle Theft Deterrent (VTD) Description and Operation: Notes

WARNING: This page is about a different car, the 2003 Buick Regal and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

The personal automotive security system (PASS-Key(R)) is an internal function of the Body Control Module (BCM). The PASS-Key(R) system is designed to prevent vehicle theft by disabling the starting and fuel delivery systems unless an ignition key with a specific electrical resistance is used to start the vehicle.

There are 15 different ignition key resistance values. Of the 15 different resistance values, or key codes available, only one will work with each Body Control Module (BCM). Once the key code is programmed into the BCM, the code is stored in non-volatile memory.

The Powertrain Control Module (PCM) enables engine starting when the PASS-Key(R) system detects a valid coded key is being used to start the vehicle

If the wrong resistance value is sensed when the ignition switch is in the ON position, the PCM will disable the starting and fuel delivery systems for approximately 3 minutes. The security indicator will be illuminated until the 3 minute timer has expired.

IMPORTANT: If the PASS-Key(R) system detects an open or short to ground when the ignition switch is in the ON position, the BCM will default to fail enable mode. The vehicle will not stall or stop running. If the BCM is in fail enable state when the ignition is turned OFF, it will remain fail enable until the next time the vehicle is started. If the BCM is fail enable the PASS-Key(R) system is NOT active and the vehicle will start. The PASS-Key(R) system includes the following components:

Ignition key
Ignition cylinder
Body Control Module (BCM)
Crank relay
Powertrain Control Module (PCM)
SECURITY indicator