almost got it sorted just cannot access 13 Auto Dist Reg in VCDS the controller is not responding
followed these instructions all of it worked but cannot access STG 13
Coding applies to Audi A6 C8
STG 19 > Installation List > "69 - Trailer/Anhänger" - Activate
STG 01 > Coding > Byte 5 > Bit 4 "Trailer installed" - Activate
STG 09 > Coding > Byte 13 > Bit 4 "Hitch ECU,installed" Activate
STG 13 > Coding > Byte 3 > Bit 3 Activate
STG 17 > Coding > Byte 14 > Bit 5 "Trailer, YES" Activate
STG 46 > Coding > Byte 14 > Bit 6 "Trailer control unit, 0=not installed / 1=installed" Activate
STG 6D > Coding > Byte 01 > Bit 7 "Trailer Recognition installed" - Activate
STG A5 > Coding > Byte 14 > Bit 1 "FW_AAG,installed" Activate