Corrado V6-2792cc 2.8L DOHC (1992)
Digital Idle Stabilizer: Description and Operation
Idle Air Control Valve
PURPOSE
The idle air control (IAC) valve maintains proper idle speed under various engine load conditions.
CONSTRUCTION
The idle control valve consists of windings, an armature, a return spring, and a rotary slide.
OPERATION
The Engine control module regulates idle speed by controlling the amount of time the winding is energized. The amount of bypass air is
determined by the position of the rotary slide.
The Engine Control Module compares actual engine speed with programmed speed. By varying the time the winding is energized, the opposing
forces on the armature against the return spring cause it to take a fixed position, allowing the correct amount of bypass air to maintain the correct
idle speed.
The ECM monitors the IAC circuit for open and short circuits. If a malfunction occurs, idle speed defaults to a fixed "warm idle" speed.
