Idle Control System

Idle Control System:

DESCRIPTION AND OPERATION
The Idle speed of the Engine is controlled by the Idle Air Control (IAC) Valve.

The Valve changes the amount of air bypassing into the Intake Manifold in response to electric current controlled by the Engine Control Module (ECM). When the Idle Air Control (IAC) Valve is activated, the Valve opens to maintain the proper idle speed.

Idle Speed (rpm):

After the Engine starts, the IAC Valve opens for a certain time. The amount of air is increased to raise the idle speed about 150-300 rpm.

When the coolant temperature is low, the IAC Valve is opened to obtain the proper fast idle speed. The amount of bypassed air is thus controlled in relation to the Engine Coolant Temperature.