Auxiliary Intake Air Control Solenoid Inspection with Scan Tool

The auxiliary intake air control solenoid is operated by the powertrain control module (PCM). The PCM supplies a ground path to the solenoid control circuit using an internal solid state device called a driver. When the PCM commands the solenoid ON, the voltage on the control circuit should be near zero or low. When the PCM commands the solenoid OFF, the voltage on the control circuit should be near battery voltage or high. When the solenoid is energized, manifold vacuum is applied to the vacuum motor and the auxiliary inlet air duct door is closed.