A4 B5 Quattro Instrument Cluster

Hello everyone,
While it's a gasoline engine, I don't think that's a major issue in this case.
My acquaintance bought the vehicle, knowing that the AI (artificial intelligence) system was defective.
"The indicator lights occasionally illuminate without a clear reason. The mileage reading changes randomly; he received a note from Audi stating that the error was read from the memory."
Control unit: 8 y 919 03 y
Encoding 00063.
Workshop code: WSC 65543.

65535 - Control unit defective.
00-00 - -

That's what it says on the note.

It makes me a bit suspicious, as I suspect it might also be a mileage counter.
Is it really true that his STG (Steuergerät) is defective, or is there still a chance to fix it?
Happy Friday!
Greetings.
Thilo.

EDIT: It's a 1994 model, but it has been modified with facelift parts. Presumably, the instrument cluster (KI) has also been replaced.
"Or was the larger BC already available in the year 1994?"

When it comes to used cars, there are always obvious issues, and in the end, many people sing the familiar song...

The part number in the log doesn't match, so it's possible that the memory content is corrupted. However, it's best to simply read the data again from scratch and see. The control unit doesn't store the entry with the value 65535 for no reason, and sometimes it might be possible to recover something. However, whether it's worth it given the vehicle's age is a different question.