About a year ago I serviced my air compressor utilising Bagpipe Andy's kit. This fixed the Fault alarm showing up until this week when the alert came back on. The car rides just fine and doesn't settle at all. The car is garaged all the time, and I only use it Sundays and car club runs. It has only been in the rain a couple of time so I cannot see that the desiccant beads can be wet.
I originally suspected a faulty height sensor, could this be the reason? The fault light is not on all of the time but tends to show mid-way through a drive, but not every drive. VERY FRUSTRATING.
Any help would be appreciated.

 

Bob,

Very frustrating. I'm no expert but have (and am again!) suffering from the same issue.

My experience was similar, presented with an amber dash light and air suspension fault on the dash. Plugged in the Jaguar diagnostic tool and saw that the tank pressure was low AND offside front sensor was either not moving with the rest while driving or going to an extreme position. My point being in 2 parts - the simple message on the dash describes very little and that the diagnostic tool can likely tell you everything you need to start focusing on your issue.

If you're near Darlington (UK!) I'm more than happy to plug the tool in and see what it tells us.

EDIT - apologies just saw you're on the other side of the world to me..!

 

Hi Bob,

I concur with TomX350. As there can be multiple fault sources, reading the fault codes would be the first step for a diagnosis. Hopefully you have access to a reader or, better yet, SDD.

Best regards,

Thomas

 

Without a scan and an actual code or list of codes from the Air Suspension Module, troubleshooting is pure guesswork, and possibly throwing money into unneeded parts in the hope that they are the problem. There are 5500 failures that could throw the message up on the screen, with that number being only a slight exaggeration. Symptoms alone will NOT define the source of the dash message.

 

Thank you gentlemen, for your responses. I do have an iCarsoft diagnostic unit (I should have thought of this to start with).
Of course the fault light is not showing now!!! however 2 "faults" are shown.
1. Reservoir plausibility error
2. Battery module out of range. ( I had a new battery put in 9 months ago )
I will check when the warning comes on again.
I will check for air leaks around the tank.

 

It's possible the battery module out of range is old. When starting, the best thing to do is clear all the codes and then work new ones as they appear.

Reservoir plausibility is a symptom more than a hardware cause. It simply means the pressure did not come up as expected, and the system gave up and shut off the compressor. Again, might have been an old message. Any number of causes for the error exist: poor compressor operation or leaks in air lines, bad valves or valves stuck in the wrong position.

 

Sometimes the cylinder needs to be replaced, not just the piston ring.
Saw a set up on the computer, but after replacing both my compressors.
Picked a couple sets up, rebuilt my old ones, & put them on the shelf.
Both should work when & if needed, as they still ran.
If not, no big loss of time or cash.

 

Continuing on my journey to saneness with my Jag the Air Suspension Fault pops up sporadically. My iCarsoft tells me It is the RESERVOIR PLAUSIBILTY ERROR. I have checked all the air connections around the tank and manifold with soapy water but no indications of an air leak.
What do I do next ?

 

That error is so vague as to be nearly useless. All it tells you is that pressure is not coming up as expected, but no indication of why. Bad compressor, a leak, bad valve somewhere, I don't know if there's a way to test the compressor outside the car, just to see how much pressure it can build into an attached tank, but it could well be simply a bad compressor. Replacing it and still having the problem because the cause is something else would be frustrating, and expensive.

You're at the point that I was when I said *BLEEP it* and ordered coilovers. The air system is nice, if it works, but it's O-L-D, and well past its design lifetime.

 

I am stubborn and would not ditch the system yet. I also do not agree to the statement that the system is past its design lifetime.

Unfortunately,same as the error code itself is vague, also the description and possible causes for the fault code are very vague in the manual:


So, I would suggest to widen the search for a leak to the parts that you have not checked yet.

Good luck!

Best regards,

Thomas

 

I used to have at the beginning of my ownership of the X350 the C2303 problem. After a long research plus try & error frustrating moments I found by case out that the upper earth point behind the right headlamp was the culprit. When I tried to clean the earthpoint, hardly touching it it snapped off. After having created a new point I've never seen the DTC again. It happened around 130 000 kilometers ago.
Good luck!
R.

 

Thank you Ramon, I will give that a go and let you know the result.

 

The desiccant beads get water logged from the compressor running and compressing air. ALL air compressors create moisture when running. It has nothing to do with rain or the weather. If you check yours I would bet they are soaking wet. The couple I have worked on were all this way.
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I did a full service on the compressor about a year ago and dried out the desiccant beads in the oven. The warning indicator was absent for a long time afterwards but eventually returned. Maybe I have to do it again but with new beads. I checked the earth connection behind the left headlamp but it was sound.

 

You seeing the limitations of the air system? I bet if you take it apart again it will be water logged. The system has little to no ability to exhaust all the water that's created by compressing air. The large over the road trucks do this with a shot of high pressure air every so often plus they use dedicated air dryers as the water problem is so bad. Everyone knows that sound from driving around trucks.

I wondered about new beads too? I also baked mine and thought getting new would be better but at that time I did not know where to get them?
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Previous post has the exact problem with these air suspension systems. There is no way to remove water once it gets in. The only effort to prevent water is the desiccant chamber in the compressor, and when the beads get saturated, water gets in. Valves rust, water collects in the pressure tank and the struts, and you can't remove it. Ever. So even fixing the desiccant with new or refreshed beads still leaves you with water circulating around inside. Seems so simple to simply use a dedicated, serviceable dryer on the compressor outlet, and a drain plug in the pressure tank. If you use air tools, your compressor has both, and the system lasts for decades.