replacement of data bus control unit

[surfatwork]

Hi,

This forum has a wealth of info - thanks to you for your time and patience!! I recently bought a used 2005 B6 passat (1.9 TDI S) with a FSH. It worked fine for the first couple of weeks, but then a number of warning lights lit up.
The steering light warning lamp lit up yellow and flashed red. stayed lit.
The ESP light went on. went off after some time in some cases. In some cases, it went off after the car had been switched off and on.
The parking brake light went yellow, with a message that there was a parking brake fault.
The oil indicator flashed, with a warning to STOP, with a message "oil pressure engine stopped"
The rev meter needle went crazy
The engine temp guage went to 0

Most things, except the steering light, went off if the car was switched off and back on again.
I took it to a VW dealer, who did a diagnostic check, reset the faults, asked me to drive around until the symptoms appeared again, did a diag check again and stated that the "Data Bus Control Unit" had to be replaced at a cost of ~220quid (parts and labour).
Has anybody experienced anything like this? ANy idea what the problem might be? and what might be getting replaced? I asked the dealer for the exact part name and they said that was the VW term for the part being replaced.
many thanks,