The Passlock™ system is designed to prevent the vehicle from starting if the correct ignition key is not used in order to start the vehicle. The ignition key, in normal operation, allows the ignition lock cylinder to turn. When the ignition lock cylinder turns, the Passlock™ sensor sends an analog voltage to the body control module (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). When the PCM/VCM receives the correct password from the BCM, the PCM/VCM allows the fuel injectors to operate.