VERACRUZ(EN) >2013 > G 3.8 DOHC > Fuel System > Engine Control System > Variable Intake Solenoid (VIS) Valve>Description and Operation  
Description
Variable Intake Solenoid (VIS) Valve is installed on the intake manifold and is used to improve intake efficiency.
1.
Low/Middle Speed: VIS Valve Close → Resonation Effect → Improving Intake Efficiency
2.
High Speed: VIS Valve Open → Improving Intake Inertia Effect → Improving Intake Efficiency