Idle Up Control Valve: Description and Operation

A/C Idle-Up Vacuum Switching Valve (VSV):

Whenever the ECU senses activation of the air conditioning compressor, the A/C Idle-up VSV is activated to increase base idle speed. The A/C Idle-up VSV is a calibrated air bleed around the throttle valve and feeds air to the engine through vacuum hoses. The A/C Idle-up VSV inputs the ECU through terminal ISCV.