The idle speed control is an electronically operated valve that controls the air flow into the engine. Symptoms of a failing idle speed control include stalling at idle, difficulty starting the engine, or an abnormally high idle speed. The idle speed control valve's integrated motor is electronically controlled by the car's engine management system. When the idle speed control fails, you can change it out for a new one.
Locate the idle speed control. The exact location will vary depending on your vehicle make and model, but it is normally located next to or behind the throttle body. In most cases it is physically bolted to the throttle body. If you have difficulty locating it, consult a repair or service manual specific to your vehicle.
Unscrew the idle speed control valve from the throttle body using a screwdriver. Some vehicles may use small bolts instead of screws. In that case, use a wrench to remove them. Disconnect the wiring harness and pull off the valve. If the valve is out of reach, unbolt the throttle body from the intake manifold and pull it off to gain access to the valve.
Install the replacement valve. Seat it on the throttle body and tighten each screw or bolt firmly. Replace the wire harness. Bolt the throttle body back on the manifold if you had to remove it.
