Idle Speed/Throttle Actuator - Electronic: Description and Operation

Mounted on the front of the intake manifold, this component adjusts and maintains idle speed as required. The regulator contains an electric motor which positions the valve between the fully open and fully closed positions. The valve consists of two coils fed by battery voltage through the fuel pump relay and grounded by ECU control. With the ignition On and the engine not running, the ECU grounds one coil, opening the valve and allowing maximum air bypass to occur. The valve also remains open during engine cranking. When engine speed increases above the predetermined limit programmed into the ECU, the ECU will ground the second coil while opening the circuit to the first coil. By alternating the ground control of the two coils as required, the ECU can adjust the air bypass flow rate to maintain proper idle speed at all times.