Getr.Emergency program….Let read out and nods broken?

Hello guys, I need your help for my brother-in-law. So… I have an e38 735ia bj 96 with 230tkm and he only drives in the transmission emergency program… When I was reading out I was now at 4 different workshops, Auto Plus (they have no idea), then with a friend, who said fixed brake speed monitoring, the service mobile from BMW and also ZF Magdeburg have the same result. At ZF he was to check today. They then checked the fixed brake speed monitoring and d it’s probably fine. So the gearbox is probably not defective, but it doesn’t get into the control unit. In his opinion, it could have 2 reasons: 1: control unit in ***** or 2: wire harness defective…. you have more idea…. what should I start with… how should I proceed?? In a workshop, a mechanic had already measured the wheel running sensors and refilled the gearing oil (no idea if he had guessed) but didn’t do anything! today the emergency program comes now without the “back” and somehow also later…. if I switch to D after the start and go from the brake because he also rolls off like a healthy car by himself (you know what I mean) and if I give gas he stutters a little and because comes the message drivenot program… He always wants to switch but somehow can not properly mfg