it's bad news(especially if it seems more like a crossed B)... some comunication issue between the BCU and IDM(part of the interior fusebox) or internal fault of BCU... if you have no idea what i mean it would be quite hard for me to explain the whole story in english... what you can try as a trick is to disconnect all the plugs from the interior fusebox, check for corrosion/water ingress connect them back, put ignition on pos II, leave it so 5 minutes then see if it cured it... check for water ingress at the BCU too(behind glovebox) ...if no joy you need somebody who really knows D2 electrics with a tester cos you might need a new/known good BCU