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
|
