Error code P0234 = boost pressure exceeded

[cit-rotti]

Error code P0234 = boost pressure exceeded.
Temporary fault - occurred 2 times in quick succession in trailer mode about 1900 kg at approx. 171000 km.
Vehicle: C5 R/2007/2,2 HDI/175PS/ VF7**************[VIN obfuscated, can be read by forum staff]
Now to my problem. I know that this error can have dozens of causes, but maybe with the error code and the following description a narrowing down is possible.
The vehicle goes into emergency mode and can therefore hardly be driven in trailer mode.
Of course, a diagnostic device to clear the fault was not included.
After stopping, disconnecting/connecting the battery (negative terminal) and the obligatory minutes of silence, the box worked again.
Questions:
The model has 4 solenoid valves and lots of vacuum hoses for the turbo control - is there any sign of damage in the turbo control or was it just a coincidence?
Or even a turbo damage with a jammed adjustment or or...?
Thank you for any information and help.
Greetings Wolfgang

[GiveMeABreak]

Hi Wolfgang

If this fault is present, then official guidance is to replace the turbocharger pressure regulation electrovalve (1).

I believe that is part: 1618X2.

[cit-rotti]

thanks for the quick information

Greeting Wolgang

[xantia_v6]

Also check that the filter on the atmospheric port of the valve is not blocked or obstructed.