Don't know but I got the same message today with my 2004 530i. Tried to start the car thnis morning and had trouble getting it to crank. It eventually started and a bunch of warning icons flashed through the little window in the dash. Then the transmission fault message appeared (gear with an exclamation point inside). I went to the idrive window and had two other control messages. One said I had a cruise control problem. The other said my car clock and calendar were wrong because my battery had been disconnected, which to my knowledge is incorrect. I'm waiting for a report from the dealer.