An important part of the car's electronic system is the engine control unit (ECU) in a Volkswagen. The Engine Management Unit (ECU), also referred to as the Engine Control Module (ECM), is in charge of managing and regulating a number of engine performance factors, such as fuel injection, ignition timing, and emissions management.

The ECU is often a compact computer unit that collects input from different sensors dispersed throughout modern automobiles, including Volkswagen models. These sensors keep an eye on things like exhaust oxygen levels, engine speed, throttle position, airflow, and coolant temperature. Based on this information, the ECU adjusts engine performance, fuel economy, and emissions in real-time.