Engine power supply system and grounding
The power supply system of the engine mainly includes the controller ECU power supply, sensor power supply, starter power supply and battery charging.
ECU power supply ECU (Engine Control Unit) is an engine control unit. Its function is to collect the input information of each sensor, perform calculation, processing, and judgment, and then output commands to control the work of the actuator, so that the engine is in the best working state. The “brain” of the engine. In order to ensure the reliability of the ECU’s work, the power supply circuit of the ECU should be controlled as little as possible to ensure that even if the engine or other parts of the vehicle circuit fail, the ECU can be guaranteed to be uninterrupted. Therefore, the ECU generally supplies 24 V power directly from the battery (called constant power), and is not controlled by the main power switch and other switches of the vehicle.
Sensor power supply The sensors currently used are basically powered by 5 V, which are all generated inside the ECU. The power supply line is directly from the ECU to the corresponding pins of the sensor, without external access.