Hello all,

The kit arrived (top quality!!) and the rebuild was completed. The compressor aluminium was in awful shape from corrosion, but it does look like the critical sealing faces were present. The pressure will happily get to 9-12 bar while driving around. Put back in and the error did not reappear.

For a while... (Maybe 10 minutes)

I would have expected the fault to come back after 2-3 minutes before the rebuild.

I can clear all DTC's and drive around for 10 minutes or so before the error reappears. (Code C2303)

10 days later and I have been driving around with a severely low rear offside. This was a result of inflating and deflating the rear axle with the SSD to see if the rear height sensors are responding and running out of laptop battery!

Tonight I had a bit of time so once again cleared all errors and logged the height sensors and pressure while driving.

I can see that all heights are moving around a few mm while driving, fronts both dip when braking etc - seems like 'real' readings. Apart from rear offside, which never moves and constantly sticks at -2mm, no matter what.
​When the rear offside was in the arch, -2mm. When it's also too high, again -2mm.

Time for a new height sensor I guess. However, I still have C2303 present as the only ASU code logged.

Could a bad ride height sensor do this? Or was the compressor rebuild an improvement but not enough?

What would be the next test you'd do to work it out?

Cheers!



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Yes and yes! Those plausibility errors are tough because so many things can cause them. They don't help in any way to troubleshoot the problem.
Since you have SDD are you familiar with the leveling calibrations?
I would change that sensor and then use SDD to set your ride heights. If you get sneaky you can even use this to lower the car by tricking it a bit.

If you want here is some factory training stuff for background?
Sorry it's too big and I can't upload it.
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Great, ok - as long as the answer wasn't a ln absolute no on the sensor I'll go ahead.

I'm comfortable with the calibration and certainly plan to bring it down a bit!!

Yes I'll certainly take the factory stuff, please!

 

It's about 10 MB so I can't upload to the forum?
I can send it somewhere?
Let me upload it to a temporary site?
Give this a try? It will be good for only 7 days.

Air Suspension Factory Training Guide
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​​​​​​Thank you - that's really informative.

Just trying to find a height sensor now... I also noted that the pressure sensor value would vary between 0.4 and 11 bar or so while driving around yesterday, however it does seem that it should always have a good pressure in the tank..

One thing at a time. Height sensor first then onward.

Cheers

 

Keep reading there is a lot to the system as you have found out.
I hope you can get it all fixed and working as Jaguar intended it to.
Post back if you can as we all still have a lot to learn!
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Hi
did you put in new heightsensors and did you resolve the problem.

 

Hm kind of, it now sits very evenly and very low and tells me that there is an air suspension fault (amber light) and that the vehicle is too low (red light). I reckon the sensor did need replacing however the compressor needs doing, too. That's on 'the list'...

 

How low? Ist the body reaching over the tires but you can get a finger in between tread and plastic liner? If that's the case you can drive carefully just around the block with 25 mph to get the compressor to start again and maybe raise the car.

The compressor gives in good confdition about 14 bar. The tank gets about 12 bar of it. The air struts have a retention one way valve to keep at leat some defined pressure in it so it does not sag competely and destroy inner components.

The airstrut is air bladder used as spring and shock absorber in the center with oil . Is there any residue on the outside on the aluminum part. Then there is the airline connector with an olive inside ( best not to take apart , breaks easely) but the seal can be replaced. Under neath is that one way retention valve . If you turn it out the rest of air will come out , exchange the seal o-ring .
next part on top is the electrical connection on top goes in only one way .two needles in it have a look at those if ok

 

Driving around to get the compressor to start does no good once a warning light appears. Once you get a yellow or red condition in the air system, it gives up and will NOT run the compressor or make any effort to correct the ride conditions until the car has been shut off and restarted. It will then try normally until it gets another code condition.

I see that you did the new ring in the compressor, but I don't see anything about getting down into the dryer cylinder. If the desiccant is saturated, you haven't fixed anything, as water is being pumped in every time the compressor runs, and there's no way to remove water from the system.

Beyond that, the most likely cause of C2303 is a leak. The system throws the code when the reservoir is not maintaining expected pressure for how long the compressor has been run. The leak could be an air line joint, one or more of the struts themselves, or even an internal leak like a solenoid not closing because of corrosion.

When I ordered the compressor kit and disassembled the compressor, I found that the desiccant chamber was actually a water tank, completely saturated beads and water sitting in the "dryer" chamber. Further down, all the springs, washers, and the vent solenoid were heavily corroded. I went ahead and installed the kit, new desiccant beads, and cleaned everything as best I could and reinstalled, but I had no change. The car would sag overnight, come up OK within a couple of minutes of startup, and then throw a C2303 within 5 or 10 minutes.

After seeing how much water had to be in the system, and knowing that in Florida, there's no avoiding humidity, I ordered a set of Arnott coilovers and never looked back. This is now the best, most comfortable car I've ever owned.

 

Update, fitted a new (pattern) compressor today, completely sorted after a recalibration.

For anyone else doing this, this is what I did:

Fit the new compressor
(on startup the red light and 'vehicle too low' error was gone, although it hadn't changed height)
Clear all DTC
Set to transport mode
Cycle ignition
Set to customer mode
Recalibrate suspension
Verify heights

This may be way wrong, but it worked.

Desiccant was bone dry, but that doesn't mean it's effective. I didn't change it.

Beautiful ride restored.

Thanks to all who helped, hopefully you won't be hearing from me for a while

 

Cool another Fault resolved