How do you get rid of this fault ? Thank you. 2006 XJ8 L

 

I am not sure, if my answer matches your question...
1. I was not aware that the XJ8 has air suspension - at least I do not think that my X308 has air suspension.
2. My '97 Ford Fairlane NL came from factory with auto-adjust suspension - which I think was some kind of self-regulating air-suspension. But this system was prone to failure and a previous owner already ditched it (=threw it out) by not connecting the compressor-connection anymore and pulling the fuse for the system.

 

Your car is a later series. The X308 series ended at 2003.

 

I'd ask in the right section, I think that'll be a x350.