An electronic control unit (ECU), also known as an electronic control module (ECM), is an embedded system in automotive electronics that controls one or more of the electrical systems or subsystems in a car or other motor vehicle.
The electronic control module is an onboard computer responsible for keeping your engine running at its best and alerting you when something is wrong.
The Powertrain Control Module (PCM) is an essential part of your vehicle’s electronic management system. Often considered the vehicle’s brain, the PCM is a multifunctional controller that oversees and manages both the Engine Control Module (ECM) and the Transmission Control Module (TCM).