Another solution borrow from others in bimmerforum:
Ok so the same thing happened to me this morning. As some of you may know we've had a crazy amt of rain here in socal lately and I think that the moisture may be a culprit. Here are what my symptoms where and what I did to fix it:
Symptoms
* Speedo, Tach, Gas, Coolant Temp, MPG, Odo,
gauges not working
* None of the steering wheel buttons are working
* Turn signals not working
* Fan works but A/C does not
* Radio works
* ABS and Seat Belt lights work
* Instrument cluster lights up
How I fixed it:
Tried to perform the Instrument Cluster Self Test (hold down the trip button, turn key to position 1) but that didn't do anything. VERY IMPORTANT: I then left the key in position 1 then opened up the fuse box and checked fuses 10, 34, and 43 by taking them out and putting them back in. All the fuses were fine BUT when I took out the last fuse (43) and put it back in I heard this strange motor sound and then magically the instrument cluster started working.