The vanes are operated by vacuum. Check the vacuum lines, they are in the passanger side of the engine compartment by the radiator bottle. There's a small filter that looks like a gas line filter that is a maintence. The plastic control valve is there also. It's all there by the radiator bottle. On VW tdi's with about the same garrett turbo they can stick and all that's needed is to reach down and operate the linkage by hand to free it up. Without more checking don't jump the gun and suspect the turbo
