Body Control System Description and Operation: Key-In-Ignition

When the ignition key is seated and rotated in the ignition switch, the key-in-ignition switch contacts close grounding circuit 80. The body control module (BCM) monitors the state of the key-in-ignition switch, the state of the ignition switch (OFF, ACC or RUN), and the drivers door to control the key-in-ignition chime.