Door/Trunk Ajar Indicator/Lamp: Description and Operation

Door Ajar Indicator Description and Operation

Door Ajar Indicator System Components

The door ajar indicator system consists of the following components:

* The body control module (BCM)

* The instrument panel cluster

* The driver door latch

* The passenger door latch

* The left rear door latch

* The right rear door latch

* The liftgate actuator/ajar switch

Driver and Passenger Door Ajar Operation

When the ignition is ON, the body control module (BCM) supplies a 12V signal to the signal circuit of the driver jamb switch and a shared signal circuit of the passenger, left rear and right rear ajar signal circuit. The ajar switches are normally open when the doors are completely closed. When a door is open or ajar, the ajar switch will close providing a ground path for the ajar signal circuit. The BCM will detect the voltage drop in the ajar signal circuit and will then send a serial data message to the instrument panel cluster to display the door open indicator:

Gate Ajar Operation

The body control module (BCM) also supplies a 12V signal to the signal circuit of the liftgate ajar signal circuit. The ajar switch is normally open when the liftgate is completely closed. When the liftgate is open or ajar, the ajar switch will close providing a ground path for the ajar signal circuit. The BCM will detect the voltage drop in the ajar signal circuit and will then send a serial data message to the instrument panel cluster to display the gate ajar indicator: