Passlock sensor data is supplied to the body control module (BCM) by circuit 1836.

The Passlock sensor data supplied to the BCM is in the form of V-codes or voltage codes. When the proper ignition key is turned in the ignition switch, the correct V-code is supplied to the BCM. The BCM responds by sending a serial data password to the engine controller allowing the engine to run.

The security resistor is bypassed under a tamper condition, a possible external magnet applied to the sensor. In this mode, a specific V-code is supplied to the BCM. The vehicle will not start in this mode.