I have a Tiguan 2.0 TSI.
Is this the vacuum pump check valve? It's on the large pipe that goes from the vacuum pump to brake booster:
Or this? It's on the small pipe that goes from vacuum pump to somewhere at front of engine:
EDIT: After further scouring the parts catalogue I think the bottom is the N75 valve. Is the top photo the check valve?
There's also this right on the pump port: