Also known as the engine control unit (ECU), the ECM is essentially the brain of the car's engine, constantly monitoring and adjusting various parameters to ensure optimal operation. One of the primary functions of the ECM is to manage the fuel injection system, controlling the amount of fuel that is delivered to the engine based on factors such as engine speed, load, and temperature. This helps to maximize fuel efficiency and reduce emissions, making the Prius one of the most environmentally...