I had to clean my IAC , because they get carbon on them.
A IAC (Idle Air Control) lets air in to raise your idle. it's a controled air leak around the butterfly. Usaully it makes your motor idle high, it will only go to close, not below normal idle, unless you have the base idle set to low.

Codes are for emissons & sensers. The IAC is actuator not a senser. You can check them with a 5v battery, to hear it switch, if it switch's it's good. remove & clean the inside with carb cleaner first, then test it off the motor.

Pat