Theory Of Operation
WARNING: This page is about a different car, the 2016 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.
The purpose of the diagnostic is to monitor if the hard-wired ignition signal state is equal to the ignition signal state received on the Controller Area Network (CAN) BUS. The CAN message is sent by the Body Control Module (BCM) to the Transmission Control Module (TCM).