The Full Form of ICV is‍ Idle Control Valve.

The idle control valve, also commonly referred to as the idle air control valve, is an engine management component that is found in one form or another on the majority of road going vehicles. Its purpose is to control and regulate the engine idle speed, increasing and decreasing it as necessary to keep up with operating conditions.

Most idle control valves come in the form of a motorized valve or motor that is mounted somewhere on the vehicle’s intake manifold. The valve or motor is controlled by the engine control module, which will adjust the idle speed according to parameters such as engine temperature and electrical system load.

When the idle control valve fails it can cause all sorts of issues with the vehicle, and in some cases may even render it undrivable. Usually a bad or failing idle control valve will produce a few symptoms that can alert the driver of a potential issue.