Theory of Operation
WARNING: This page is about a different car, the 2011 Jeep Patriot and 2011 Jeep Compass. However, it is still accessible from the selected car via links, so may be relevant.
The Controller Area Network (CAN) is a high speed serial communication line for multiplex communication between multiple controllers that reside on the network. The Transmission Control Module monitors the transmit and receive message from the CAN BUS.