Getting back to your tpms malfunction, there should be a few threads related to that. I recall getting that error after about 6 years of ownership. The batteries in the sensor of each wheel just start to die so get a new set of compatible sensors in them. That's all I had to do.

How old is the car?

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'08 X5 3.0si - Alpine White / Saddle Brown interior
Specs: Sport Pkg, Premium Pkg, Tech Pkg, Comfort Access, Aero Kit, Style 433 staggered 20s on Conti DWS
Mods: Carbon 35 tint, LED angel eyes, GP Thunder 7500k fogs, H&R 20mm/25mm spacers, clear reflectors, gunsmoke-tinted taillights
Coded: Digital speedo, windows/sunroof/tailgate close via keyfob

X5 pics at Flickr