Intermittent lack of boost pressure, 1.8T AUM

Good evening, everyone.

Here's the translation:

"This is about a VW Golf 4 GTI 1.8T with the AUM engine."

I'm experiencing a problem where I sometimes have no power or boost pressure. When I then turn off the engine and restart it, it has full power again.
I have the following error codes in the engine control unit's memory:

• Pressure drop at the loader - throttle valve.
• Engine control unit (ECU) locked, intermittent.

Could the problem be related to the N75 boost pressure control valve?
How can I measure that?
Because the boom on the loader should actually be working again if it restarts and functions properly.

Best regards,

Hello!

It's been a few years, but I had a similar problem with a friend's car back then.
I can only say that it was an Audi A4, also with a 1.8 T engine.

I can't remember the exact symptoms anymore; it's been too long, but back then I had to replace the turbo.
The wave, which operates the spark plug valve, was completely dislodged from its housing. Really extreme.

Take a look at this as well.