V157 motor for intake manifold flap

[T!M]

Audi A4 Avant 2.0 tdi 2006 B7 BRE

I've spent a few days trawling through the forums but can't find a definitive answer for my car.
The EML has come on, OBD codes P2100, P2102 and P2108.
These all point to a fault with the anti shudder valve.
When I clear the codes the EML goes off and remains off until the engine is turned off and re-started, then the EML comes back on and the same codes are generated.

I've removed the valve cleaned and inspected it (part number 03G 128 063 C)
The electronics compartment was full of oil and I've cleared this using carb cleaner.
There are no broken teeth on any of the gear wheels and no sign of overheating or any other damage.
The flap moves freely over it's full range and springs back to the open position.
I've also used a multimeter to check fuses F1 (air conditioning), F4 (radiator fan), F6 (air conditioning) and F25 (heater blower) and all are ok.

I've read that other members have replaced the valve and this has not solved the problem.
Before I go down that route I'd like to carry out voltage checks at the four pin connector and continuity checks back to the ECU connectors but haven't been able to find any wiring diagrams or information about the power supply or signal lines.

Any help would be much appreciated.

[philipharmes]

Did you take out the drive motor when you had the plastic electronics cover off ?

The motor commutator & brushes all get covered with the semi-conductive oil & need washing off with solvent.

I think you would have a different code if it was a wiring fault.

[T!M]

I didn’t but I’ll give it a try tomorrow, thanks for the advice