So I took my 05 VDP in for service - a new fuel filter and install the undershield that was on back order. They did a complimentary 30 point inspection and it passed with everything fine.

I couldn't get to the dealer in time before service closed, but they left the keys with the front security desk so I picked up the car at 9pm. When I started it, for the first time ever I got an "Air Suspension Fault" warning message and a audible alarm. Also my parking sensors weren't working. I'm thinking what the...car was fine earlier this morning when I dropped it off.

So I put it into drive and I hear this loud crack from under the car. I then drive home (as nobody is at the dealership and I have no other way of getting home as I didn't bring my cell phone). I thought I would leave the car there and tell them to find out what they did and correct it, but nobody was there. So I drive it home and it is making odd noises and the suspension is bouncing around and it felt like driving on a trampoline. So I get home and get out to inspect it for collision damage and find none. However, the front end of the car is low - almost sitting on the wheels, and the trunk is high - perhaps it look so due to the front end being unnaturally low.

So I'm trying to think of what happened, and inspecting the car I notice the rear doors are frozen shut, as is the trunk lid/ The car looks cleaner than this morning, so I guess they washed it. It is -9C out (15F) so I think maybe the car is frozen if they sprayed it with water outside on this cold a day. I keep it in a heated garage and usually park it in a heated underground garage when shopping or at work. So perhaps being wet and outside for the afternoon in 15F weather has caused the suspension problem?

So I put it in the garage with the heat on for an hour, then start it up and the parking sensors are working. I get out and look at the front end and can hear the compressor running and the front end lifts up. Putting it into R and then D does not cause the Air Fault warning to come on. I just drove it around the block and it is handling normally with no fault message.

I should name the car Christine - it heals itself

Seriously though, perhaps the water froze and anchored the car in the snowy parking lot, so when I started it at the dealer's, the compressor met resistance trying to raise the front end so stopped trying? Then the loud crack was the ice anchoring the front end breaking the connection when I drove away, and the car did not try to level itself again. Then, after I heated the car, the compressor worked as normal again? I hope that is all it was and the fault will not reappear. It isn't used to being outside for hours in 15F temp after being sprayed with pressurized water.

 

Update: drove the car yesterday for a couple of hours - no fault messages and everything is working fine. I guess it doesn't like sitting in freezing temps for hours after being washed. Will advise dealer not to wash it outside until the temps go above freezing in the spring.

 

They don't like altitude, much, either. Across Arizona, Colorado, and Wyoming at various altitudes between 1500 and 3500 meters, I'd get air suspension faults, too. Always corrected itself on restart, but would report the failure almost immediately when higher up.

You could have had a partial ice blockage of the compressor intake, which would act just like the thin air I encountered.

Even an XJR is running a bit short of breath at 3500 meters.

 

Good diagnosis! The cold causes contraction in the struts and the front will drop as the air leaks (slowly) out of the air bags. When you start the car the compressor will attempt to pump up the front but if it cannot within a certain amount of time, about 90 secs. I think, it will give up and cause a fault. Usually this results in a very hard ride. As things warm up under the hood the leaks reseal but the compressor will not retry to lift the front until you restart the car.

As far as the parking sensors not working, maybe they were covered with a thin coating of ice. I know my cruise control won't work if its front sensor it covered with snow.

I agree, the car can be freaky. I get a kick out of how it "exhales" when you first unlock or open a door.

 

I too lived with this problem for a short time. Eventually went to dealer. Had to replace right front strut. All is working fine now.

 

Ummm... actually what happened was that when the car is in the lift (which they need to do at the dealer) the tires hang down and the sensors read as if the car was super high. Since the car has two rear height sensors and one front sensor the rear height is directly monitored but the front is calculated. When they put the car down the front goes down and the rear adjusts fast and stays up. After that you need to clear the faults with a Jag tool and drive the car a little bit and the car goes back to normal. I do this for every customer... But you said they were closed so I'm guessing they just finished in a rush to get home and just parked the car. I see this all the time. I even saw an XJ that when I lift it up in the lift the air suspension spring blew out (small heart attack )