Engine Control Units (ECUs) are digital computer systems integral to modern engine management. Located within the vehicle’s engine compartment, ECUs receive inputs from numerous sensors monitoring engine and vehicle parameters – including temperature, airflow, and throttle position. Utilizing pre-programmed maps and algorithms, the ECU calculates optimal ignition timing, fuel injection duration, and variable valve timing. Outputs control corresponding actuators, ensuring efficient combustion, emissions control, and overall engine performance. Advanced ECUs increasingly incorporate diagnostic capabilities, facilitating fault code reporting and system monitoring via standardized protocols.