Electrical problem

On my sisters 99 xj the speedometer and the rpm gauge will suddenly stop working then they will come back to life. But while not working no bus (or no bu5) will pop up on the odometer. What does this mean?

Don't know about the code it's throwing, but my 91XJ did this when the speed sending unit went out. It's easy to fix and relatively inexpensive. Goes down by the transfer case, if I remember right, and only has one nut holding it in.
hth, dn