What are the main functions of a car ECU?
2 Answers
The main function of a car ECU is to compute, process, and judge various information input by engine sensors based on its stored programs, then output commands to control relevant actuators, achieving the goal of fast, accurate, and automatic control of engine operation. The working process of a car ECU: when the engine starts, the electronic control unit enters the working state, certain programs and steps are retrieved from the ROM and enter the CPU. Under the control of the CPU, each instruction is executed in a cycle one by one. The engine information required during the execution of the program comes from various sensors, and the signals from the sensors first enter the input circuit for processing.
After repairing cars for twenty years, I believe the ECU is the brain of a vehicle. It controls core functions like ignition timing and fuel injection, ensuring the perfect air-fuel mixture. Last time I encountered a car with poor acceleration, the diagnostic tool showed abnormal ECU data from the oxygen sensor – replacing it fixed the issue. It also manages turbocharger pressure and automatically increases idle speed when the AC is on in summer. Nowadays, even auto start-stop and transmission shift logic fall under its control. Without checking fault codes, repairing modern cars is practically impossible.
