Body Control Module (BCM)

The Passlock (TM) logic is contained within the Body Control Module (BCM). When the ignition lock cylinder is turned to the CRANK position, the BCM monitors the Passlock (TM) data from the Passlock (TM) sensor. The Passlock (TM) sensor sends an analog voltage to the BCM. The BCM determines the validity of the voltage and sends a class 2 serial data password to the Powertrain Control Module (PCM)/vehicle control module (VCM). If the password received by the PCM/VCM is not the same password as the last learned password, the PCM/VCM will not allow the vehicle to start. This condition causes the fuel injectors to turn OFF and the security telltale to turn ON. The BCM continually inspects the operation of the Passlock (TM) system during the vehicle's operation. If the Passlock (TM) system telltale turns ON continuously during the vehicle's operation, refer to the Passlock (TM) System Check.