GM Service Manual Online
For 1990-2009 cars only

Door Ajar

The audio amplifier activates the door ajar audible warning as requested by the body control module (BCM). The BCM sends a serial data message to the radio indicating the chime frequency of a medium rate and continuous duration. The door ajar warning sounds and the door ajar indicator illuminates when the following occurs:

    • The BCM determines that the driver door is open and the signal circuit is low. The instrument panel cluster (IPC) also receives a serial data message from the BCM requesting illumination of the door ajar indicator.
    • The vehicle is not in PARK. The BCM receives a serial data message from the ECM or BCM indicating the gear position.

Trunk Ajar

The body control module (BCM) monitors the trunk ajar switch circuit. The trunk ajar switch is normally open when the trunk is fully closed. When the trunk is open, the trunk ajar switch contact closes providing a path to ground. The BCM detects the drop in voltage and sends a signal to the driver information center (DIC) which displays the trunk ajar message.