Audi a4 b8 2.0tdi turbo actuator problem

[Speedkg]

Hello,
Im having a problem with turbo actuator for nearly 2 months.
Problem is: when glowplugs light(coil) start to flash car lose power and after a while mil icon apears aswell.
Is happenas randomly, even on start and in the middle of driving.
Diagnostics shows turbo actuator low input as i rember well.
So turbo was removed cleaned and changed full cathridge. So basicliy new turbo,and was tested on machine with old actuator and results are great.
Turbo was back on car and same error...
My mechanic told it has some bad circuit 5v to the actuator, electic mechanic messed with some pins on some connector near car computer(some white conector) suggesting that there starts bad connection to voltage problems on actuator. And again same error. Glowplug light still flashes. Pls if some1 had problem and fix pls write it.
Thanks.

[VAG-Abound]

Does that mean that the electrician thought he'd identified a problem with the 5V line, but didn't fix it? Or he did try to fix that but the problem remains?

It does sound like it could be a fractured wire, where the signal is lost briefly causing the ECU to go into limp mode. Can you get a reading of stored errors using VCDS or similar?

What is the engine code - something like CAGX?

[Speedkg]

Hello,
Thnx for replying
He did fix "something" some loose contacts, wire was tested and is ok, its not broken.
Problem still remains, it was bad conduct thro the wire on the actuator,and that fixing of conectors solved problem with 5v. That is what he told me...

[VAG-Abound]

If that fix did nothing and you still have the same problem than perhaps it was never a problem in the first place, although it might have looked corroded.

Code reads may give a clue what is happening.

[Speedkg]

Il read codes again tomorrow, had one code and is related for actuator.

[Speedkg]

Still dodnt fix it. Code is P256400

[Crasher]

You need to have the setup checked using a vacuum pump and measuring blocks display