Oh ich kann mir selber helfen. Der Dank geht an eak aus dem jeepcherookeeclub.com.
How to access Dealer menu?
All the 3 buttons at the same time. UP DOWN temp control driver side AND Windshield defrost for about 7 sec
Also there is a engineering menu.
Driver AND passenger temperature buttons up and down pressed together for 7 sec (all 4 buttons at once)