What is a TCM Module?
By JEREMY PROOME on Jul 14, 2025A Transmission Control Module (TCM) is the unit that controls the gears and transmission operations of a vehicle. It can also be referred to as a Gearbox Control Unit (GCU).
The TCM unit received a variety of signals from the car’s sensors, and adjusts the shifting timing and speed of a vehicle in order to achieve better performance.
The goal of the TCM is also to ensure that gear changes are smooth in order to avoid damaging your gearbox and causing a lack of power.
TCMs have become more popular in vehicles in recent years due to the increase in automatic cars and the focus on making transmissions as efficient and environmentally friendly as possible.
If a TCM is not working properly, it can cause a few problems with your car, including poor engine performance, worse fuel economy, erratic gear shifting, and even a complete transmission failure.
Of course, the more electronics in a vehicle, the more things can go wrong, and TCMs can inevitably complicate a car’s functionality. Having a faulty or non-working TCM checked by professionals is a way to find out if you need a TCM repair or replacement.
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