Variable Induction Control Actuator: Description and Operation

High Speed Inlet Air (HSIA) Control Solenoid:

The High Speed Inlet Air (HSIA) solenoid controls the vacuum apply to the inlet air shutter valve actuator. The solenoid is controlled by an output signal from the PCM. The HSIA solenoid allows vacuum to close the shutter valve at low rpm. Above 5000 rpm, the solenoid vents actuator vacuum to atmosphere, allowing the shutter valve to open.