Theory Of Operation
The Intake Swirl Valve (ISV) Actuator is located under the Intake Manifold. The ISV Actuator is not accessible without removing the Intake Manifold. There is a short jumper harness from the ISV Actuator that can be accessed for performing checks of the main (Actuator) wiring harness. The ISV Actuator is used to simultaneously position two flap shafts (one for each engine bank). Each ISV flap shaft has three valves (one for each cylinder). The ISV Actuator is supplied with 12 Volts by the ASD circuit and is controlled by the Powertrain Control Module (PCM) using the Swirl Valve Control circuit which is Pulse Width Modulated (PWM). There are also two ISV Position Sensors which are separate from the ISV Actuator. They are mounted at opposing ends of the Bank 1 and Bank 2 ISV flap shafts. These Position Sensors are monitored by the PCM over the ISV Position Sensor 1 and ISV Position Sensor 2 circuits. The Intake Swirl Valves are used to create turbulence in the air entering the combustion chamber which helps to reduce emissions.