Audi A6 C5 Allroad transmission conversion: from Multitronic automatic to manual

Hello everyone, here's a problem:
The conversion from automatic to manual transmission is already complete, but I'm stuck because I have two errors stored in the brake control unit: [Error 1] and [Error 2].
Data bus, drive system: No communication with the transmission control unit.
Control unit incorrectly programmed.
The engine control unit cannot be reprogrammed, even though the other control units and vehicle configuration data are correctly coded, and the drive system is already properly configured.
Regarding the car: Audi A6 C5 Allroad, year 2002, 2.7 bi-turbo.

Hi.
Then you'll probably have to find a suitable engine control unit (ECU) from a manual transmission version... assuming that version even existed.

Thank you for the quick response. Yes, it already existed as a manual switch.

I also have a control unit in my A4 Quattro that cannot be reprogrammed, for whatever reason.