Circuit/System Verification
WARNING: This page is about a different car, the 2007 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
Ignition ON, observe the scan tool Door Ajar Switch parameter in the Driver Door Switch data list, Passenger Door Switch data list or the BCM Doors data list (rear doors only) while opening and closing the suspect door. The door ajar switch parameter should change between Active/Inactive or Door Ajar/Door Closed.