Circuit/System Description

WARNING: This page is about a different car, the 2015 Chevrolet Trax and 2015 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.

If the vehicle is equipped with power windows without the express features or with manual crank windows, the body control module (BCM) will provide a 12 V signal to each door ajar switch via the door ajar switch signal circuit. The door ajar switches are normally open when the door is fully closed. When a door is opened, the door ajar switch contacts close providing a path to ground. The instrument cluster receives a serial data message from the BCM indicating the door ajar status, the instrument cluster will then display the door ajar icon.

If the vehicle is equipped with express power windows, the window motors or the window switches each provide a 12 V signal to their respective door ajar switch signal circuits. The door ajar switches are integral to each door latch assembly. When a door is opened, the normally open door ajar switch closes. With the door ajar switch closed, ground is provided to the door ajar switch signal circuit and the voltage within the signal circuit drops. The window motor or the window switch will detect the voltage drop and will send a serial data message to the body control module which will then send a message to the instrument cluster to command the door ajar icon.