Description and Operation: Description

The 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 the following table).

Fig 1: Identifying Variable Intake Manifold Solenoid (VIS) Valve

Courtesy of KIA MOTORS AMERICA, INC.

ENGINE CONDITION AND VIS VALVE OPERATION CHART

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

Fig 2: Identifying VIS Valve Operation At Low/High Speed & Medium Speed

Courtesy of KIA MOTORS AMERICA, INC.