What is the function of idle speed control system?

The function of the idle speed control system is to realize the stable operation of the engine at the target speed, the rapid warm-up after the engine is started and the idle speed adjustment after the air conditioner is turned on, so that the engine can meet the requirements of different idle working conditions. The structure of idle speed control system consists of three parts: sensor, ECU and actuator. The actuator of the idle speed control system is the idle speed control valve (ISCV). The basic principle of idle speed control system is the function of engine control system to maintain normal idle speed, that is, idle speed control function. The traditional idle speed control is the original manual control or mechanical control, and the modern new automobile idle speed generally adopts ECU intelligent control. The ROM of the engine control module ECU stores the optimal idle speed (target speed) in various idle states. When the engine is idling, the ECU determines the target speed according to the engine state parameters detected by the sensor, calculates the difference between the target speed and the actual speed, determines the control quantity, drives the idling control device, makes the actual speed close to the target speed, and changes the intake air.