I have a 2004 X5 4.4i with the 2 axle air susp. system. I woke up one day and went out to find my trucks rear suspension completed inflated, one side a little more than the other. The front looks normal. So the first thing I did was check the fuses, 57 in the front and 79/87 in the rear, all good. Next, I took the spare tire out and inspected the rear system, all good connections, all dry in battery comp and in compressor comp. All lines looked good. When I opened the door or tried starting the truck the compressor does not come on or make any noise. So none of the shocks are damaged but the compressor has stopped with the rears inflated. Next I replaced the control unit, located behind the glove box, which I bought at a auto wrecker used, new one cost 700 min. Did not fix the problem so took the truck to a shop and when the tech put the scanner on it came up air susp. system not found or wording like that. Basically he said that his scanner was not able to check or correct anything because his scanner was not reading it. ANYBODY KNOW MAGIC>>>>