in 01 add tow hitch think its byte 5 bit 4
In 03 abs go to adaptation add trailer stability
In 05 go to adaptation add vip tow hitch
In 09 security access 31347 go to adaptations add tow hitch
In 10 add tow hitch
In 13 add tow hitch(aag)
In 3c add tow hitch(aag)