2009-2012 Honda MUV700 Big Red Service Manual, Page 57Get this manual
TECHNICAL FEATURES IACV (Idle Air Control Valve)
The IACV consists of step motor and slide valve, and controls the amount of air bypassed around the closed thronle valveWith the ignition switch ON, the amount of idle air is determined by the PCM from information detected by various sensorsDuring engine start-up or while maintaining idle (throttle valve closed)the amount of inlet air is continuously adjusted according to various sensors' informationThis system eliminates the need for manual idle speed adjustment and high altitude adjustment settings
THROTTLE BODY
AIR BYPASS
OPERAnON
The PCM controls the lAC during engine idling only, so the PCM stops controlling the IACV and leaves it in the closed position when the PCM detects the followi ng: Throttle valve open Gear position switch is in gear position (except neutral) During engine idling and warm up, from the time the ignition switch is turned ON, the PCM controls the lAC step motor as follows: With the ignition switch ON When the ignition switch is turned ON, the IACV Is initialized and the step motor will operate: The slide valve goes from the open position, to the closed, and again to the open positionEngine starting and warm up While the throttle valve is closed, the bypass opening is optimized by the IACV, and the correct amount of inlet air passes through allowing proper engine starting After the engine has started, the PCM controls the IACV step motor to adjust the slide valve position by processing various sensors' information This results in reduced amount of bypassed air compared to the amount during engine start-up, and initiates engine warm-up for several minutesU