Modern cars are more like computers on wheels and central to that is the ECU. If the engine is the heart of the car, the Electronic Control Unit or ECU is its brain. Your car may develop a fault that you think is mechanical but actually the real culprit could be the electronics, caused by a malfunctioning ECU or one of its sensors.
The ECU is now such a crucial and integral part of our cars that I think it’s worth understanding exactly what it does.