What function does the ECU perform to maintain engine speed under varying loads?

The function of maintaining engine speed under varying loads primarily falls under speed control, which is essential for ensuring that the engine operates efficiently regardless of changes in demand. The engine control unit (ECU) continuously monitors various parameters such as engine speed, load, and environmental conditions. Through this monitoring, the ECU adjusts the throttle position, fuel injection, and ignition timing as necessary to keep the engine at the desired speed.

While throttle adjustment, fuel modulation, and ignition timing are all important aspects of engine management, speed control specifically focuses on the overall regulation of engine RPM in response to different operational demands. This is achieved through a combination of the aforementioned adjustments, but the overarching goal is to stabilize engine speed. For example, when an increased load is detected (such as when climbing a hill), the ECU will increase fuel delivery and adjust the throttle accordingly to prevent a drop in RPM, thus exemplifying speed control in action.