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 (IPC)

* The driver door latch

* The passenger door latch

* The left rear door latch

* The right rear door latch

* The rear compartment lid latch

Driver and Passenger Door Ajar Operation

The body control module (BCM) supplies a 12 V signal to the driver door latch and to the passenger, left rear and right rear door latches. When a door is open, the switch within the door latch closes providing a ground path for the ajar signal which causes to voltage to drop to 0 V The BCM will detect the voltage drop and then communicates this status to the instrument panel cluster (IPC) via a serial data message. The IPC, upon receipt of this serial data message, will illuminate the ajar icon.

Trunk Ajar Operation

The BCM also supplies a 12 V signal to the ajar switch within the rear compartment lid latch, this switch is closed then the trunk lid is closed and the switch is open when the trunk lid is open or ajar. The normal voltage state with in the ajar signal circuit is 0 V when the trunk is closed and firmly latched. When the trunk is opened, the ajar switch will open causing the voltage to rise to 12 V and will then function the same as when a door is ajar or open, the BCM will send a serial data message to the IPC to command the ajar icon to illuminate