I have read through a bunch of "Air Suspension Fault" threads and have not found my particular situation.

Today started 550 miles from home. About 25 miles into our trip the "Air Suspension Fault" came on the screen. I could hear the compressor running and the ride went incredibly stiff. Got out, and the right side of the car was "way high", probably 5-6" of clearance above the right rear tire. The front was elevated but not nearly as much. I assume the front was just compensating for the rear being so high.

Being that I had to be home before tomorrow I took the chance and continued on our journey, albeit with a significantly rougher ride. Being that I was traveling with a little girl, we stopped several times at rest areas for 5 or 10 minutes with no change. 250 miles into the trip I stopped for gas and potty break. I didn't notice, but the car had leveled out (during the fuel stop). I did notice that the "Air Suspension Fault" message had clear and didn't return. Along with the ride returning to "normal".

Strangely the fuel gauge took that moment to stop working. Even though I had just filled the car, about 2 minutes back on the road, the fuel gauge showed empty and the Nav unit was showing me Gas Stations. When stopping at the rest areas the fuel gauge would work for a couple of minutes upon restart and then go to empty.

For the last 300 miles, the suspension work fine, the ride was good and the car drove like it should. (other than the fuel gauge)

Literally as I pulled into my driveway the "Air Suspension Fault" error came back. As I exited the car the rear right was now in the "down" position. As if there was no air at all. The right front was a bit low, but i assume that is due to the rear being so low, similar to when the rear was extended high.

Again, as if somehow related, the fuel gauge now works. I took the car for a short trip to the quarter car wash to remove the bugs and road grime. The fuel gauge worked fine, I did get the "Air Suspension Fault", but it didn't complain about the car being to low.

Do I have a bad rear shock? Bad sensor? Could I have damaged the compressor by driving it? What the heck does any of this have to do with my fuel gauge?

If I did additional damage by driving the car, I will just have to suck that up, as I had to be home today, important business meeting tomorrow.

Thanks for any insight you can offer. I will be making the trip to the dealer, but since everything I know about my car I learned here, I want to arrive at the dealership armed with knowledge.

Thanks for any help you can offer.

Dave

 

Your problems could be caused by bad wiring loom connection(s) and/or bad earths (US=grounds).

For the suspension, you could also have a bad height sensor, or the connections to it are bad or failing, (see above). FWIW, the system controls each rear spring unit separately, and the two fronts together. Later cars only have one front height detector as Jaguar soon realised having two in this situation was pointless. One bad rear height sensor will result in the ASM trying to maintain a level car, so what you describe would not be unusual symptoms.

My Technical Notes also says: -

- Raising has priority over lowering
- rear axle rises before front axles
- front axle lowers before the rear

Hope this helps you a bit. You also need to read the codes to see what the system has detected.

 

It leveled out overnight on Sunday, was perfectly OK all day Monday, no error, and properly level. I will be driving it longer distance today. My appointment at the dealership isn't until Friday, so we will see how it goes.

 

In the days before fault codes, intermittent faults like yours were extremely diificult to sort out, and tended to disappear the moment a mechanic started to look at the car !!

So we have advanced a bit if the stored code gives a clue as to the component that seems to be in trouble, even though the car may now be behaving normally.

Anyway, us "fortunate" to own a classic car on 35 years old get our troubles too. Clutch slave cylinder failed on my MG Midget on Sunday and I only just managed to get home. Being recovered to the shop today.

 

Well the problem returned yesterday. I pulled the positive wire on the battery and let it sit overnight. We will see if that has any effect today. At least I am starting the day with the shocks where they belong.

 

Since the fuel gauge issues have gone away, I am assuming I need a rear height sensor. I see they retail for $110, what will it cost me to get installed?

 

Well, it shouldn't be too expensive in labour. The road wheel will probably need to come off. About 30 minutes, I'd say.

However make sure it really is a duff sensor. I saw a recent post where the wires were exposed into the connection, allowing salt and water in. Corrosion of connections puts a resistance into the circuit. There is also an earthing point in the boot by the spare wheel; is this secure ? It's just that a fuel gauge error, and a rear height sensor are in the same place and surely wouldn't fail simultaneously.

 

You were correct. Although I wish it were the sensor...one of the sunroof drains is broken and the water was running onto the connection by the wheel. They want $1100 in labor to fix it. They say replacing the plugs is the easy part, but they have to take the headliner out to replace the drain hose. Ouch.

 

Very sorry to hear of your travails. How on earth can a sunroof drain break, its not a moving part ! Sounds like somebody has been in that area and fiddled about before you got the car.

 

I'm not sure what "broken" means either. They called late on Friday night. I will call back monday AM and make sure they don't mean "clogged", which they should be able to clear without replacing the part.

 

I wonder if the attached TSB is relevant?

 

Sure seems relevant to me. I'll be printing this out and taking it with me.

Thank you so much.

Dave