What is the Dodge Cummins Communication Module? It is an additional Bus expansion port for the Smarty Touch. What does it do? When installed to Smarty Touch’s under-dash controller, it allows the communication with the ECM over two distinct CAN Bus channels at the same time. The usual OBD II plug / bus and a secondary under hood service bus used by Cummins for the communication with external modules such as the VGT turbo, Oxygen sensors, etc. Why is it needed? 1) The Smarty Touch uses the under hood service bus for real time On The Fly (OTF) tuning for all years from 1998.5 to present *. 2) The Smarty Touch uses the under hood service bus to unlock the 2013 ECM’s. Why additional hardware? During the development of the Smarty Touch we could not anticipate that we would have needed a third CAN Bus port to communicate with an ECM. When the 2013 trucks hit the market it became clear that to unlock and communicate with those ECM’s a whole new strategy was needed.