Level Control Malfunction

[ozam]

My wife's 07 X5 4.8 (sport package with 3rd row) is the bane of my existence. If it wasn't for the remarkable support of my local BMW dealership it would have been gone a long time ago! I think I've counted something like 25 visits to the shop!

Unfortunately the car is no longer under warranty as six years have passed. Recently the car has been throwing off the level control malfunction warning (once every week or so). Normally I just turn off the car and turn it back on and it goes away. If on the rare occurrence that the car is listing to one side (usually) the right, I just take it for a drive and it seems to level out.

Any continuous compressor noise seems to be coming from near the front right tire and not the rear (but I rarely hear it).

So my question is whether there is a procedure to diagnose the issue, i.e. how to determine whether there is a switch, compressor, or airbag problem. The parts are expensive and I do not to start replacing things until I know what is wrong.

Any ideas would be appreciated!