Got a Strange Instrument Cluster Problem

[BimmerM3inGA]

OK, folks. I haven't posted in a while because, amazingly, my 2002 X5 4.6is has been behaving itself for the last several months. Well, all good things must come to an end…

A couple of weeks ago I was running errands when all of a sudden the instrument cluster just went crazy. The needles bounced up and down, lights when on and off, and so on. I did some quick research and learned that pulling fuses 1, 43, and 45 would reset it. So I pulled the fuses and it seemed to work. Note that the battery is fairly new, but this X5 is not my daily driver so it was possible that the battery could be low on juice. So this past weekend, I put it on a battery charger just to make sure the battery is okay. The alternator is also a relatively new OEM Bosch rebuilt unit.

I was about 20 minutes into my commute to work this morning, cruising on the interstate (minding my own business, I might add), when all of a sudden the cluster did the same thing again. The speedometer needle froze, the temp gauge pegged at full hot, and the various warning lights flashed and eventually it settled on what you see in the first attachment.

Since this area is heavily patrolled by the local law and state patrol, and I'm driving a bright red BMW, I didn't want to continue without knowing how fast I'm going. So I pulled into a rest area and shut it down and restarted. What you see in the second attachment is after restarting. So I pulled the fuses again. Again, it fixed the problem. But now I know the fix will only be temporary.

So, what's really going on here? How can I diagnose and permanently fix this problem? I don't even know where to start!