Theory Of Operation
WARNING: This page is about a different car, the 2015 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.
The Body Control Module (BCM) is the Local Interface Network (LIN) master for the Power Top Control Module. The Power Top Control Module performs a series of self-diagnostics as well as monitoring the Power Top Motor and Power Top Switch. As the LIN master, the BCM receives a set of required messages from the Power Top Control Module indicating the status of the components monitored by the Power Top Control Module.