The transmission control module (TCM) is an essential component that makes sure your vehicle switches gears as smoothly as possible. The TCM synchronizes with the powertrain control module (PCM), so your transmission can shift in the best way for the engine's load.
Input and output parametersA modern TCM utilizes signals from engine sensors, automatic transmission sensors, and from other electronic components that decide when to shift. Some designs get data from an input to the ECU, whereas older models would have their system and sensors on the engine parts. New transmission control units are tricky because they have many factors and there are numerous shifting behaviors.
As for the output parameter, the newer TCU transmits signals to shift solenoids, pressure control solenoids, and other electronic parts. The shift solenoids in new automatic transmissions are engaged to change gears. Older models of the automatic transmission were made to only utilize a single line pressure control solenoid, which adjusts the pressure of the engine transmission.
Common problems with a faulty transmission control moduleA faulty transmission control module can lead to erratic shifting, stuck on the same gear, and poor fuel efficiency.