I'm having a similar problem, without the message light. Rear end squatted and wife drove it and it cut the inside of the tires.(ouch) I've checked both fuses 7.5 and 30 amp and also there is a relay inside the airpump housing, all checked out. I jumpered a paper clip after I removed the relay and pump came on.( so i know pump is good). I jacked up rear end and cleaned right rear sensor and put back together and started X5, everything came on and leveled out. All was well, or so I thought, next morning rear end squatting. I ordered new leveling sensors from ECS tuning.com, only problem was backordered, so I had to go to the dealer.(extra 20 bucks) They will be in this Monday and i'll install them on Wednesday, hope it works or next step will be leveling computer. Thanks for all the great info on this subject.