Description And Operation: Operation

Engine condition	VIS valve	Operation
Medium speed	OFF	Increasing engine performance in low engine speed by reducing intake interference among cylinders
Low/High speed	ON	Minimizing intake resistance by shortening intake manifold length and increasing area of air entrance

Fig 1: Variable Intake Manifold Solenoid (VIS) Valve Flow Diagram

Courtesy of KIA MOTORS AMERICA, INC.