Idle Air Control
PURPOSEMaintains the proper idle speeds during warm-up and with different engine loads.
OPERATION
When the engine is cold, the A/C compressor is on, the transmission in gear (A/T only) or the alternator is charging, the Engine Control Module (ECM) controls current to the Idle Air Control (IAC) valve to maintain correct idle speed by introducing more air into the intake manifold.