Idle Up Control Valve: Description and Operation

Idle-Up/Fuel Pressure-up Vacuum Switching Valve Systems:

Whenever the ECU senses an electrical load from the neutral start switch, starter relay, tail light relay or defogger relay, the Idle-up VSV is activated to increase base idle speed. The Idle-up VSV is a calibrated air bleed around the throttle valve and feeds air to the engine through vacuum hoses. The Idle-up VSV inputs the ECU through terminal V-ISC.