Hello Ralf,
I also have a Passat AJM, manufactured in 1999 (2000 model year).
85KW PD.
The beeping is also annoying me, and unfortunately, it seems like it can't be turned off.
But resetting works perfectly according to the instructions, I've done it several times before, I don't currently have the exact sequence in mind, but as far as I remember, the pen must be at the display of the instrument panel when the !! is switched off. Turn the ignition on.
...it has been perfectly fine 3 or 4 times already...
'I'm more troubled by the performance issues and the excessive diesel consumption.'
Hoping you can understand this statement.
See you later
Thorsten
P.S.: If you have any questions about the type, just email me. It might take a while, but I'm also happy if someone who drives the same model can answer. (By the way: Our Passat also has the same technology package!)