Variable Intake Solenoid (VIS) Valve
WARNING: This page is about a different car, the 2021 Hyundai Kona. However, it is still accessible from the selected car via links, so may be relevant.
VIS (Variable Intake System) is a device which varies the length of intake manifold to generate maximum power at certain RPM. VIS lengthens intake manifold to improve the torque at low RPM when vehicle speed is low while it shortens Intake Manifold to raise torque at high RPM when vehicle speed is high. PCM controls VIS using RPM signal.