Land Rover Repair: Range Rover, airsprings, full tank

Question
I have a 2001 Range Rover and for the 3rd time the same problem has occurred.  While I am driving the car will give an error showing the car with an arrow pointing up.  then the car will lower itself and I cant drive more that 30 miles on it.  Last time it happened I got sick from all the bucking the car did.  all land Rover does is idle the car or open the doors over night and it goes back to normal.  They claim there is 120 things that can cause the car to do that but they keep tell me its the suspension.  I asked them to take care of this problem while it was on warranty and they did not.  Now the car is out of warranty and they tell me it could be a number of things but they don't know what.  

Please has this happened to anyone else and what is causing it.

Answer
This is very common, unfortunately most dealerships do not want to take the time to diagnose and repair the system, the just re-set the lockout and send you on your way, for it to fail again.

Most likely you have a combination of leaky airsprings and a worn out compressor.  the compressor is pumping slower because it's been doing extra duty to keep up with the leaks.  now it can't keep up with the leaks, so the suspension cannot maintain height, a fault is logged, the suspension is locked out (the go-kart ride) and you are forced in to the dealer again.  Leaving a door open with the engine running allows the compressor to fill the tank without filling the airsprings as well, so when you drive off you have a full tank of air, this is quickly used up by the leaks and the slow compressor cannot maintain so you get another fault.  The first step is to rebuild your air compressor, then test the rest of the system for leaks and either rebuild your valve block (if it's leaking), replace your airsprings (if they're leaking) or both.  

The air suspension is just like your brakes, when the fault light comes up on the dash it needs to be fixed, not just reset the light and hope it doesn't happen again.

The 120 things it could be is somewhat correct, there are 120 possible faults that the suspension ECU can log, they are all problems within the air suspension system, not across the whole truck.