Vane Actuator VNT-15/VNT-17 (A4 ALH);

New VNT actuator, or vane actuator, for the VNT-15 (stock turbocharger for 90HP ALH TDIs) and VNT-17. Actuators can stick or fail, often because of corrosion. VNT vanes will not adjust properly if the actuator malfunctions, causing limp mode, low power, check engine lights, smoke, and low fuel mileage. Replacing the actuator is a good alternative to buying a new turbocharger, the only option in the past.