Seems like there are various versions of the same theme. I have a 2006 X5, and have just been hit by the Trifecta.
I sent it to BMW, and they have indicated that it is a problem with the Transfer box. I have difficulty believing this (probably 'cause I dont want to).
First error message was "4x4 DSC disabled", now the msg is "check brake linings"
Could the problem really be the Trf Box?
But have had misdiagnosis in the past few months. My air con was slow to start working, so I sent it into an upmarket area dealer who told me the compressor was faulty and needed to be replaced. Not convinced I got a second dealer who told me it was the electric radiator fan. Two "reputable" diagnosis, both $1500 each to repair, had I followed the first I would have doubled my cost!
Hence my lack of faith in the diagnoistics of the local dealers.