This fault usually logs when you have a loss of vacuum in the vac circuit.
A quick indication of loss of vac is to switch the engine off while observing the manifold flap, if it crawls into the closed position or doesn't work at all you have a loss of vacuum.
Mityvac reading should be 20"hg or thereabouts at idle (off memory).
If you have a live reading for the Air Mass on your scanner, with the engine warm - attach the Mityvac to the EGR Valve, apply vac to the EGR - (it should hold vacuum) the air mass reading should drop to 250 mg/st from 400 at idle when the egr is opened.

I have only seen one VAG egr inop due to a faulty valve, have seen plenty of them inoperative due to loss of vac.

Jon.