Hi all. I’ve been having issues with my rear air suspension on my X351. It started with the rear right that one day decided to lower itself. This resulted in a tilted drive. I scanned for codes and it showed a front right ride height sensor problem. I ordered one but it was non oem when I got it in the mail. Right now however, the ride has gotten so much worse. I basically have no rear right suspension and the ride is very harsh and bouncy. I live in a country where importing parts is a nightmare. I’m trying to find if the X351 shares any components with other jaguars or Land Rover products. I’m even considering swapping the rear airbags for springs if I can find any OEM springs that will match the dimensions and ignore the fault codes on the dash. All I’m interested in is a drive able car

 

Good luck on swapping to springs. That was never an option and I have never seen a kit either. The reason why is the rear air suspension is extremely reliable and has few problems. That was one change for the better compared to the previous generations of the XJ. On those forums you will find hundreds and hundreds of threads on failing air suspensions.
You can verify this yourself by searching the forum.

When asking for help you need to help us? What are the codes? Always post the numbers. What are you using for a scanner? Do you know about SDD? Do you have a working copy? And complete car information. Yes you have an X351 so thanks for that.

Without SDD your scanner most likely can't see deep enough into the car. Especially the air suspension stuff. Does the compressor work? Are there any block valve errors?
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CloseEnough351
Check this 2dn hand provider:
https://about.ovoko.com/
I think they deliver your area as well?

 

CloseEnough351, I feel your pain. I have endured a similar issue with my 2012 XJ. I would first start with trying to figure out what the codes are. Like has been said, you are going to need a copy of SDD or a shop that has it and pay them the $125 or so to have them read the codes. That is going to help us a lot (A LOT!!!!!)

In the mean time, I would try disconnecting the battery and leaving it unhooked for say 20 minutes and then come back and let the car relearn itself. This may be enough to get the suspension to play nice. I know mine went out after I jacked the car up too much on one corner and the computer did not like that (when I replaced the front right shock due to a failed solenoid for ride comfort). The loss of power and then restoration may be enough to get things to play well again.

If the codes simply come back as the computer is not happy (the point I got to), the way I corrected it was to get a copy of SDD and tell it to go into suspension height calibration. I measured my heights with a tape measure and all of them were right around 400mm. Unfortunately, the computer was looking for values in the 200mm range. So, the computer would not accept the values (so, not sure how the special Jaguar measuring tool measures things as it supposely measures from middle of the wheel to the top of the wheel arch). But, after doing this twice and exiting out, the car suddenly straightened up its act and it worked great for the next few years.

 

I had the same issue on my X351. I replaced the rear ride height sensors with inexpensive non OEM Chinese units and they work perfectly. These are simple Hall effect sensors and nothing Jaguar specific about them.

The air suspension system itself is straightforward and does not require OEM parts as long as the sensor signal is correct. A bad sensor can cause the ECU to dump air on that corner which matches the symptoms you are seeing.

I would replace any old sensors and check the rear air bags and compressor before considering a spring swap. You can make the car driveable without OEM parts or abandoning air suspension.

 

Listen to Thermo and don't load the parts cannon until you know what's wrong. Randomly replacing parts has little chance of working.
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here are the codes I’ve gotten from the initial scan.
c1A03-78
C1A03-26
C1A07-62
C1130-7a
U3000-55
U3000-05
but since I replaced the front left ride height sensor the first code became permanent.

 

For $50 a year, you can go to AllData and have access to a lot of diagnostic trouble shooting and service, wiring diagrams etc. Topix is another really good one but if I remember correctly it's quite expensive.

I had to do the same thing as Thermo described with my XJR after replacing the air compressor and chassis control module. For whatever reason, the suspension wouldn't act right. Adaptive Dynamic faults. Got my tool (not SSD), Went into height calibration mode and like the problem Thermo had my car also wouldn't let me enter any values as they were different than what the software wanted. Okay, whatever. Backed out, tried again. Fail. Backed out again in frustration and moved on down the road. Worked perfectly fine after that.

 

CloseEnough, let me look up the codes in my service manual and lets see if there is a common thing causing all of this madness. But, you have a mix of chassis and universal codes, so, this is making me ponder what is going on. Give me a little bit to figure this out.

 

Sounds like you have a leaky rear spring, and probably now a burned out compressor after it pumping it up daily for some time. Easy enough to verify compressor operation, should hear it running with the engine running and all doors closed. If not, check voltage to it. Once you know the compressor works, then check for leaks. Once you are sure no leaks, then you can check the height sensors, but as above throwing parts at it gets expensive quickly and is a rough way to go about it.

 

Still no car info?
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CloseEnough351, well, the U3000 codes pretty much sum it up. They are saying you lost your height calibration to the ride height computer. So, it is looking like you are going to have to find someone/some shop with SDD to program the heights of your car. Now, with this being said, the computer is not happy with your left front height sensor. It may be possible that it was simply disconnected and reattached and the computer does not like that.

I mention that the left front sensor may still be an issue as the C1A03-26/78 code is indicating that in short "the computer is not seeing that corner of the car responding to bumps in the road" (ie, rate of change of the signal below threshold) which could be caused by either a bent rod for the sensor or one end of the sensor not being connected to the suspension of the car. Then you have C1A07-62 which is saying that the cross-check with the right rear as compared to the right front/left rear heights is not matching either (which if the left front is off, this would make sense).

The C1130-7a code is essentially saying that the computer has attempted to change the ride height of the car, but it saw atleast 1 wheel not responding. This would go inline with the above mentioned codes indicating that the sensor is failed or has become disconnected from the suspension.

Hopefully this helps explain what you are seeing and it will take nothing more than a good calibration of the car and you will be back on the road with no issues. Granted, I would give all the ride height sensors a good look over to see if any are damaged/disconnected.

 

Before you start throwing cash at the problem, look for the simple fix.

I would take each wheel off in turn and check that the height sensor arms move and are intact, the electrical connections are sound and the wiring hasn't become lunch for a hungry mouse. A quick squirt of WD 40 on the articulating bits wouldn't do any harm.

After that, try dumping the pressure from both air springs and then see if the system will reset itself. You don't need SDD to run the height calibration, ICarsoft V2.0 (JLR) will do it.

wombat