N75, N18 & N239 open or short to ground

Hi there

I have a vw polo se tdi, 1.4l . 2002.
Became bit reluctant to start and reduced power. Diagnostic says N75, N18 and N39 open or short to ground. Replaced boost pressure regulation valve but fuse that governs it keeps blowing. Any ideas?

Thanks for reading

Helen

If you can find a circuit breaker for that fuse, put that in. Otherwise get a bunch of fuses and disconnect each of them one at a time and see if the fuse blows. If one of them reliably blows the fuse, you have a short in the solenoid.

When does the fuse blow? Is it as soon as you put it in? Or do you have to drive it?