Variable Intake manifold Solenoid (VIS) valve is installed on the intake manifold. The VIS valve controls the vacuum modulator which activates a valve in the intake manifold. The ECM opens or closes this valve according to engine condition (Refer to below table).
Engine condition | VIS valve | Operation |
Medium speed | Closed | Increasing engine performance in low engine speed by reducing intake interference among cylinders |
Low / High speed | Open | Minimizing intake resistance by shortening intake manifold length and increasing area of air entrance |
