Having my first issue with the air suspension after owning my '06 XJ for 3 years and nearly 30k miles. Came out to the car last night and the front end was low, drove home and about 10 minutes into the drive the Air Suspension Fault and orange light came on in the dash. Got home and the front end was low and by this morning the front end was pretty much bottomed out.

Scanned the car this morning and took it for a short drive. Driver's side front seems to be at normal height now, but passenger side front is low. Only drove about 5 minutes and did not get an error light. I think the 06+ cars only have one level sensor up front so odd that the passenger side would be lower, unless this means that strut is bad? If so no big deal, have been planning on replacing them at some point anyway.

Code I got is C2302 - "Leveling Plausibility Error"

I'm sure some of you guys have seen this issue before, figured I'd ask here before starting to replace parts.

 

It is likely to be the front height sensor
or check top of strut with soapy water for leaks

 

Thank you for the reply - Is there a good way to test the height sensor? After shutting the car off and leaving it for a few hours, the right front is by far the lowest, basically on the ground. The other corners have lowered quite a bit as well, but the right front seems to be the issue. I will check for air leaks and also check the front height sensor once I figure out how to do so. Thanks again.

 

Your code reader should be able to read live data, so see what it thinks the front height is. If you can't read live data, only DTCs, then you need a better code reader.

 

Reading live data would be the easiest way.
If you can't do yourself maybe take it to a mech to have it read
but examine the sensor for possible damage first.
When one of my front struts failed when I jacked a corner up
it emitted a weeeeeeeee sound.

 

Funny you mention that wheee sound...After parking the car the right front made that noise about 15-20 minutes after I shut it off. I haven't looked at the car since last week, but fairly certain the front right air bag went bad. That corner is by far the lowest right now, but they are all pretty low after sitting for almost a week.

I have a Foxwell scanner (forget which model) and it does read some live data, I'll see if it can read the level sensors. I doubt it, but worth a shot.

 

The air bag folds over itself depending on the height of the strut
and when you jack it up the leak is exposed and you get that sound
that's my theory anyway.
Sounds like you have found your leak!

 

Hi 87LC2,

C2302 is triggered when the air suspension air compressor fails to fully pressurize the system in the time alloted by the Air Suspension Control Module (ASM). By far, the most common cause is a worn piston ring/seal in the air compressor, though a large air leak can also trigger C2302.

Our member bagpipingandy manufactures a compressor piston seal replacement kit, and there has sometimes also been a kit available from Wabco, the company that manufactured the air suspension system (aside from the Bilstein air spring/damper units). Search ebay - Kirbie Engineering Solutions is the company that markets Andy's kit.

There are photos of the rebuild process at the link in my signature. You don't usually need to replace the desiccant beads, but it is a good idea to bake them in a 500 degree oven overnight, and to clean the leaf valves in the compressor, and the exhaust valve and pressure relief valve attached to the compressor.

Cheers,

Don

 

If the car is not being used and one air bad leaks, the car will try level the car in sleep mode by releasing air from the other airbags. So the fact that the others seem low after a few days doesn’t necessarily mean there is anything wrong with them.

 

Interesting and helpful, thank you. This leads me to believe the right front damper is the issue, especially since I've never had other issues that would lead me to believe its the compressor.

 

Thanks for the reply Don. I will look into that or a new compressor as well. As I said, pretty sure its the right front damper, I'll get under there this weekend to check it out. I'd like to keep the air so replacing the front shocks along with a compressor rebuild should get me back on the road.

 

Unfortunately, logic does not seem to prevail with this air suspension system. I had the issue of the car dropping down on all four wheels after standing for about 2 days. Logically, the compressor should have nothing to do with it as it releasing air if there is too much in the system. This is controlled by the computer and the solenoid valves. My compressor worked perfectly when the car was being driven and the ride height was correct. However, replacing the compressor based on a code that appeared has resolved the issue. It no longer drops down after 2 days. The mechanics also struggled to explain this or fully understand it. It sounded more like the solenoid valves were malfunctioning and letting the air out slowly. Thankfully it has been fixed. Good Luck.

 

Was any corner much lower than the others? In my case the right front is bottomed out while the others are still about halfway up, that's what's leading me to believe its the damper unit. I need to get under there and take a look, just haven't had the time yet. I wouldnt be shocked if it was the compressor and I should probably rebuild it regardless, but my situation leads me to think there is something going on with the corner that is much lower than the others.

 

No. All 4 wheels looked the same. Your problem sounds very different and seems to be pointing to one wheel.