Hi everyone,
This is my first post and I hope you find it relevant.
I currently have a 2006 vogue and I had the same problem.
This cure only applies to vin numbers 6A198057 Onwards (around the 2006 facelift time)
Range rover have recognised a problem with "suspension fault" coming up on the dash.
My problem was with the small metal muffler on the compressor getting blocked and not letting the air in or out quick enough. If the system does not detect sufficient movement within the correct time it displays "suspension fault" and switches off the ride height adjustment.
I am no mechanic but changed this in 10 minutes with an 8mm and a 13mm socket or spanner. It is clean and easy to do.
The Uk Part number is RQV500040 and cost me £18 from the main dealer.
This is how I did it:
Take out Spare wheel under boot floor,
You will see a large black container with pipes going into the front of it and wires at the back. This is just a protective cover so remove it by undoing the 4 x 8mm bolts (one in each corner). Give the cover a gentle sideways tap just to unseat it.
Under the cover you will see the compressor, at the LH front of the compressor you will see the muffler (looks like a gold cone shaped filter), undo this using a 13mm long socket or a spanner.
With the muffler removed, start the vehicle (you can leave the tailgate open, but shut all other doors) and try the ride height adjustment. If you have no faults showing then you should be on the right track.
The new mufflers have a 3mm hole drilled sideways through them to allow more air flow.
Replace new muffler in compressor, do not over tighten.
Range Rover also replace the compressor dryer when doing this under warranty, but I have been told it is not always necessary. Mine did not need it.
Then put the cover back on making sure you do not trap any wires or pipes.
Here is a link to the Land rover tech bulletin.
https://docs.google.com/file/d/0Bzf...NmEzLThiNmQtYjUwYTA3OWQxYzFk/edit?hl=en&pli=1
I hope this was helpful and sorry for the long post.