What does ISC mean in cars?

[StFaith]

ISC stands for Idle-Speed-Control, which refers to idle speed control. Idle speed control means the regulation of idle air volume. In addition to stabilizing the basic idle speed, its functions also include integrating various features that previously required additional devices, thereby simplifying the intake system. When the engine is idling, the throttle is fully closed, meaning the amount of air entering the engine is no longer adjusted by the throttle. The essence of idle speed control is to regulate the intake air volume through the idle speed actuator, while coordinating with fuel injection and ignition timing adjustments, to alter the power output from fuel consumption during idle conditions, thereby stabilizing or changing the idle speed. The Idle-Speed-Control (ISC) system is one of the engine auxiliary control systems. Its function is to regulate the engine's intake air volume via the idle speed actuator during idle conditions, based on signals such as engine coolant temperature, air conditioning compressor operation, and transmission gear position, ensuring the engine runs stably at the optimal idle speed. Idle speed refers to the condition where the accelerator pedal is fully released, the throttle is closed, the engine has no external power output, and maintains stable operation at the lowest speed.