Unable to read error P0401 Mondeo Mk3 2.0TDCi

[ppahl]

Hello!

First of all excuse my scary english , I'm german native.
I'm driving a Mondeo Mk3 2.0 TDCi DPF build in 11/2006. Because of repeating trouble with the egr I decided to mount a blind plate for deactivating the egr - worked fine.
But every 2 years the car must be checked by the TÜV, and this month it was time to do so.
So i removed the blind plate, waited until the MIL didn't light up any more and drove to the TÜV. Bad luck, still P0401 in memory, so check was failed.
I already planned to buy an elm327 adaptor and to test forscan, so this was the time to do so (installed latest version 2.2.5 beta). But forscan didn't found any error?
OK, my thought was that the error was erased by itself in the meanwhile, so I drove to the TÜV again -> still error P0401 in memory!?!
Back at home (10min and 10km to drive) I've connected my elm327 again -> no error at all!

Any idea whats going wrong here?
The attachments show some screenshots, I think forscan recognizes all relevant modules? I even tried to read the injector values and compared them with the sticker on the engine -> absolutely correct, so it looks like forscan gereally is able to read the datas. Except of error P0401...

[FORScan]

waited until the MIL didn't light up any more

The only explanation we have is that this vehicle is OBDII compliant and the error code is stored by OBDII system (even if MIL is OFF, the code may be stored in memory). The only problem is that according to what we know, this type of PCM is not OBDII compliant, and FORScan doesn't find OBDII module on the board.

We would like to do some specific checks with your vehicle, can you please check your PM?