Body Control Module

WARNING: This page is about a different car, the 2004 Saturn L300. However, it is still accessible from the selected car via links, so may be relevant.

The BCM contains the theft deterrent system logic. The BCM reads the Passlock™ data from the Passlock™ sensor. If the Passlock™ data is correct, the BCM will pass theft. The BCM will then transmit the code password to the VCM/PCM.

During the tamper mode the vehicle may start. The vehicle will then stall. If the BCM receives the wrong Passlock™ data, the VTD will immediately go into the tamper mode. The tamper mode will lock-out the vehicle fuel injectors for 10 minutes. The SECURITY indicator will flash while the VTD is in the tamper mode.

If the Passlock™ sensor sends a correct password to the BCM when the ignition is in the ON position, the BCM will send a fuel enable signal to the VCM/PCM. The VCM/PCM will not disable the fuel due to any BCM message for the remainder of the ignition cycle.