a4 2.5 tdi faults - intake man flap & motor

[chris-p]

hello, having some issues with our 2.5TDI A4. today the car started loosing power, stuttering badly, where it was barely able to hold 30 mph, the CEL came on, so after reading it, were supplied with the following codes:

01282 - intake manifold flap change over valve (n239) intermittent

19559 - motor for intake manifold flap (v157) malfunction intermittent

Have had a look over the parts and there is nothing obvious, any pointers to start the fault finding?

Thanks