Hi
If it is a ECU from a A8, my understanding is it wont have the manual coding on it.
I was able to switch coding on my S8 ECU from Auto to Manual with no log-in required, because coding is already on the chip.
There are ways around it without coding, Tozo in the USA did it, let me see if I can find his post.
So you converted your A8 to manual gearbox?
Here is his A8 thread, not sure how much info you can get from it.
http://forums.audiworld.com/showthread.php?p=15541794
The other option is to pay someone to flash it with custom code to ignore the TCU then you can remove and junk that thing.