OK, I know this probably sounds like a silly question but I am at the end of my rope! I had a suspension warning and took my 2011 XJL supercharged to a local shop that came recommended for experience in MB, BMW and Jaguar. They replaced the the compressor (used an Arnott), the solenoid and the relay. All worked well for 2 weeks and then back comes the warning light. The shop decided they could not use an aftermarket solenoid and ordered a new Jag OEM solenoid (big red flag). They put that unit in and the warning still persisted. They then determined that the new compressor had water inside (the seal and in the desiccant) and that was causing a fault with the air release valve so they are replacing the compressor again. Then they asked me a very odd question. The tech stated the compressor is housed in a box in the trunk and he thought there should be material or a filter to help with the humidity? I assume there is space simply for airflow. I am loosing confidence with the shop and would really appreciate for guidance from anyone on this forum. I have and always will love Jags so i have to figure out how to get this issue sorted. Thanks to all in advance!

 

The compressor have "silica" dryer on it. Round part on top of the compressor. Compressor itself are located in the trunk, next to the battery. Check Service and repair manual from "Sticky" section, pages 386, 387 and 395.
Service/drying for "silica" element are done so that by SDD (factory tester) the system are unpressurized. Dryed air from resevoir dryes the element when escapes. The trunk shall be open (and sparewheel cover up) so the moist air are ventilated out. (made forced airflow if possible) Re-pressurize the system. (obiosly pick a dry day, frozen weather are the best, since there are not much moist in the air in frost temps)

Have the shop read the codes from car, or do they just change components in blind?

 

i thought they were reading the codes but now i am guessing they are not.

 

Funny, I am going through a somewhat similar scenario. Gotta pull codes. I had a permanent compressor error, and replaced it with an Arnott. It has been working well for a few months, but I am now getting a C1A13-64 (pressure soes not decrease when venting gallery). I have not really investigated it too much, but suggestions have been exhaust silencer restricted, or exhaust solenoid stuck closed, or pressure sensor fault. I am interested in what you find.

 

Yes I would be a bit suspicious of the shop too as no filter will help with humidity. That's why the compressor has the desiccate beads. Those will absorb moisture.
If you can post back with your codes. There are a bunch of them and they usually point to different things.

No much help to you but we are pretty lucky that this version of the XJ has very few air suspension problems as that was the number one failure point of the previous XJ model.
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Hi - I feel your pain and wanted to share a recent experience that may well solve your problem.

Short version: fully charge your battery. Completely fixed and you will see below my problem was real, repeatable and plainly observably with no test gear.
I am quite convinced the long periods of no driving due to COVID lockdowns created this situation

Longer version:
* I started getting Suspension Warning messages that would mostly disappear after a drive cycle (approx. 20 mins of driving)
* the fault would (mostly) recur next time I used the car
* after a week or so of this, fault worsened and became physically obvious. One side of the rear would be ridiculously high (max height) or be down on the bump stops (zero)
* booked the car into a Jaguar dealer for service
* COVID lockdown rules changed that week and I was not permitted to take the car for its repair
* plugged in scan tool, ride height sensors issues, suspension system faults, multiple module errors
* checked battery voltage: 12.40VDC at the under bonnet/hood jump points, 12.45VDC at the battery terminals. Basically a 'Good' battery reading
* no low battery warning from the vehicle or in the scan codes
* fully charged my AGM battery (remember to put the negative charger connection on the spare wheel clamp)
* once battery fully charged, take for a drive cycle (you can trigger a suspension reset by turning the steering wheel left / right etc . . .)
* problem resolved, no recurrences, completely normal vehicle operation in all suspension modes for the last four weeks

 

Never hurts to start with the battery for sure!! How old is your battery?

But he does have specific errors so that usually indicates deeper real problems.
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Yeah . . . the root of all time wasting is forgetting to deal with power issues first.
I have a good quality battery in the car but could not identify its build date. I did try; took photos, went to the manufacturers site but to no avail.
I have owned the car for less than one year so I cannot estimate its age.

Plan B: If there is any occurrence of this issue, I will have the battery professionally load tested, the charge system checked and battery changed if needed. Zero downside to this.
A final thought . . . I have a suspicion the Battery Management System was not properly in sync with the actual battery charge state.
I did read-up on the system and I can see it is designed to automatically re-baseline under certain conditions (without intervention) but that battery took a decent charge to get it back to a fully charged state.

Anyway . . . hope this helps and maybe provides another clue to the thread author @redell1

 

Thanks to all for the extremely helpful responses. The sop claims that it was simply a bad out of box Arnott compressor. I have my doubts but i guess we will see. I have had it back for a week and no faults so far. Last time the faults re-appeared after two weeks. I will post an update with the two week results. Still not convinced that i would have a bad out of box Arnott unit that failed to due moisture in the seals. .

 

I too would always consider a poor battery as a possible factor. My 3 year old XF began to not stop/start. As it was still (just) under warranty I took it to the dealer. They tested everything and put the battery on charge and declared that it was all OK. When I drove away it did Stop/Start - once, but that was it. It went back to the dealer who tested the battery and they had it overnight. They again said that the battery was fine, so I told them they had better fix the stop/start system under warranty then! At that they spoke to JLR who told them to change the battery. It's been perfect ever since. So my conclusion is that it's impossible to test if a battery is OK or not. The car itself seems to know best!

 

Can you explain how to do the suspension reset you mention? Will this level both sides or just get rid of codes. My car is running 2 cm lower on one side. Thanks

 

@Jonty Angle - for me, a simple drive cycle was all that was necessary. I do not know the exact criteria of a valid drive cycle for the x351 (other wise members will) but for me, this worked;
* drive the car for at least twenty minutes
* normal engine temperature needs to be achieved
* four or more Left and Right hand turns respectively
* normal brake
* drivers door opened and closed at least once

I believe it is also possible to trigger the automatic suspension re-calibration without a drive cycle by turning the wheel lock-to-lock in each direction four times (again, wiser members will correct me if I'm wrong)

Of course, there is an official calibration procedure available through Jaguars' SDD software. If you're up for a tech challenge . . . that would be an DIY adventure. :-)

Hope that helps.

 

Just wanted to post a quick update from my original experience: my Battery completely failed three (3) weeks ago. In the space of one night it was completely dead (I suspect a fatal internal issue).
Lessons (re)learned:
1. Open circuit measurements of batteries are only somewhat useful. You really need to load test your battery (a dedicated tool)
2. At the first sign of battery trouble in an X351, replace it. Clearly this car is heavily dependent on its power source