Module, Transmission Control: Description: M40MTA

WARNING: This page is about a different car, the 2015 RAM ProMaster 3500, 2015 RAM ProMaster 2500, and 2015 RAM ProMaster 1500. However, it is still accessible from the selected car via links, so may be relevant.

The Transmission Control Module (TCM) and mounting bracket is mounted under the left side dash panel.

The electronic control system consists of various components providing inputs to the TCM. The TCM monitors transmission sensors, shifter assembly, and bus messages to determine transmission shift strategy. After shift strategies are determined, the TCM controls the actuation of transmission solenoids by moving a sequence of four valves to make a shift occur.

The system performs its functions based on continuous real-time sensor feedback information. In addition the TCM receives information from the rest of the vehicle over the CAN C bus. The CAN C bus is a high-speed communication bus that allows real time control capability between various controllers. Most messages are sent every 20 milliseconds. This means critical information can be shared between the transmission, engine, and ABS controllers. The CAN C bus is a two wire bus with a CAN C Bus (+) circuit and a CAN C Bus (-) circuit. These circuits are twisted pairs in the harness to reduce the potential of radio and noise interference.

The transmission control system automatically adapts to changes in engine performance, vehicle speed, and transmission temperature variations to provide consistent shift quality. The control system ensures that clutch operation during up-shifting and downshifting is more responsive without increased harshness. The TCM activates the solenoid valves to manage the position of the clutch and manage gear selection and engagement.