Secondary Throttle Valve: Description and Operation

Intake Plenum Switchover Valve




Variable air induction tuning is used in order to achieve maximum performance and efficiency over the entire operating range of the engine. The intake manifold contains the Intake Plenum Switchover Valve. This vacuum operated valve is essentially a moveable divider that changes the airflow characteristics of the intake manifold. The vacuum of the valve is controlled by an ECM controlled solenoid valve. The solenoid valve is supplied power via the engine control power relay (Switched B+). The ECM controls the valve by grounding the control circuit via an internal solid state driver. When the ECM is commanding the component on, the voltage of the control circuit should be low (near 0 volts), and when the ECM is commanding the control circuit off, the voltage potential of the circuit should be high (near battery voltage).