It may be the rear "Satellites" on top of the rear shocks. This is the "brain" that controls the level, airbags etc The assembly is one piece which includes the sats and shocks. Happened to me twice when I had mu 07 4.8i. The recommendation is to change both at the same time which I did. However, at the time there was only one available and the other had to be ordered. I ran for a month with only one replaced (the side that was causing the malfunction) and all was good. FWIW, I probably didn't need the second one replaced..

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2013 BMW X6M-current
2013 Audi S4-current
2007 BMW X5 4.8i (E70)-sold