Idle switch function, circuit diagram, detection, know the speed! ! ! !

When idling, the cross-sectional area of idle air passage is changed according to the temperature and load of the engine, so that the engine has the best idle speed under different working conditions. Idle motor is mainly used to bear the idle speed of the car, and its purpose is to adjust the idle speed according to the engine load when idling. Idle stepper motor is installed on the throttle body and used by the engine controller to control the idle speed of the engine. When the engine speed deviates from the idle speed, it is adjusted by the throttle valve to control the amount of air entering the intake manifold, which is mechanically operated by the accelerator pedal wire rope. The throttle body has a bypass air passage to provide air when the engine is idling (when the throttle is closed). The pivot of the automatic idle motor extends into the bypass air channel, through which the air flow is adjusted. According to the input signals of various sensors, the engine controller adjusts the engine idle speed by moving the pivot of the automatic idle motor into and out of the bypass air passage. When the ignition key is turned to the on position, the automatic idle motor starts to work. The switch signal is input to ECU to detect whether the engine is idling. At the same time, the instantaneous position of motor is fed back to ECU through motor position sensor. Generally, four wires, two signal wires and two power wires are idle. The extension length of the motor, that is, the number of steps, is determined by the duty cycle signal of the engine.