BMW F10 air suspension compressor and level control faults
F10 Touring rear will not rise and a Level control failure message appears – what is wrong?
The most common causes are a blown 40 A compressor fuse (number 182), a faulty compressor relay or a stuck drain valve. Check the fuse and relay first. The relay is green and located at the rear. If a new fuse blows immediately, the cause is in the compressor or its connector.
How do I tell a compressor fault from an air spring leak?
If the compressor runs but the rear does not rise, the fault is in the compressor or the air line. If the rear rises after a short compressor run but sinks again over time, the springs are leaking. You can look for the leak with soapy water on the surface of the spring. Continuous running can also be caused by a hose that is not pushed all the way into its fitting.
What else can stop the compressor from working?
Moisture in the dryer granules or in the compressor connector can blow the fuse or freeze in cold weather. A stuck drain valve prevents the rear from rising, and replacing it is often the only lasting repair. Transport mode prevents the compressor from running; it is removed with BMW's diagnostic software while the battery voltage is sufficient.
When does the compressor have to be replaced?
If the rear rises slowly or a fault code reports too long a raising time, the compressor cannot produce enough pressure. Drying and cleaning may not be enough, and a new compressor fixes the fault. Check the air springs at the same time, because a leaking spring overloads the compressor and blows the fuse.