Circuit/System Description
The body control module provides a 12 V signal to the driver door open switch signal circuits. The door open switches and the door ajar switches are integral to each door latch.
The door open switch and the door ajar switch contacts will be open with the door is fully closed, the door switches within the door latch are designed so that the when the door is ajar, the contact in the door ajar switch closes, the voltage is pulled low and the window motor will then send a serial data message to the body control module indicating that the door is ajar. When the door is opened further, the contact in the door open switch will then close providing a ground for the door open signal circuit, the driver window motor will then detect that the door is open.