Right above the starter motor, it was wire number 5 that was broken. In the two Passat 35i TDI cars I had cable breaks in years ago, there were also error entries, but here there are absolutely no entries.
The VAG 1551 is an old device that VW dealerships also used. It displays various information, although some of it isn't presented clearly but rather as error codes. However, it always shows something if there's an issue.
I use it because it's robust and ready to use as soon as you plug it in.
Sommer: A4 B5 Avant 2,5 TDI Quattro Facelift (AKN silber)
Wartet auf H Kennzeichen: A4 B5 Avant 1.9 TDI Quattro (AFN Schwarz)