What Is A Powertrain Control Module (PCM) In Cars?

The PCM or Powertrain Control Module of your car is a critical automotive component or rather a combined control unit. Like human brain, which controls and coordinates the different functions and activities of human body, PCM acts as the brain of your car, and it controls and coordinates the functions of the different sub-systems of your car.

The PCM, in normal cases, consists of two sub-systems; Engine control Units (ECU) and Transmission control units (TCU). The function of the Engine control Module or unit is to ensure the optimum Engine performance by controlling a set of actuators on the internal combustion engine of your cars. The TCU or Transmission control module takes inputs from the engine sensors or TCU to change the gears for the optimum engine performance and fuel efficiency of your cars.

The PCM gets inputs from the sensors which are spread around the car and which gives information related to Engine management and performance. The other subsystems controlled by PCM include the Fuel Injection, Fuel emission, Automatic transmission and Anti-lock brake systems and so on.

As already stated earlier, since the Powertrain module controls the different sub-units of your car, whenever there is an issue with a subsystem or auto car part, it is the responsibility of the PCM to alert the driver. The driver will understand the signal and will take necessary corrective action to rectify the problem.