Theory Of Operation
WARNING: This page is about a different car, the 2010 Dodge Avenger and 2010 Chrysler Sebring. However, it is still accessible from the selected car via links, so may be relevant.
The Transmission Control Module (TCM) communicates over the CAN C bus and continuously monitors bus activity. An implausible signal (data) failure condition is when the communication network is intact but one or more signal elements within the bus message are invalid. The TCM is still able to communicate with other modules over the bus when this Diagnostic Trouble Code (DTC) is active.