Description and Operation: Description

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).

Fig 1: Variable Intake Solenoid

Courtesy of HYUNDAI MOTOR AMERICA

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: Variable Intake Solenoid Operation Diagram

Courtesy of HYUNDAI MOTOR AMERICA