2004 XJ8 new to me. Suspension is all way up all around. Battery was disconnected for 2 weeks and suspension stayed high. I loosened the Rt. Rear air hose on the valve block in trunk and both rear struts deflated. The previous owner replaced the solenoid valve block about 1 yr ago. What size rings are needed for the valve block and all 4 struts? Car has 1 yr old struts. Haven't found why the car rides all way up on all four wheels. I would appreciate any suggestions where to look. Any suggestions on how to electrically test the ride height sensors. Thanks in advance.

 

The first thing to do, and it is basically mandatory with these cars as they already have lots of electronics, is to get a specific code reader to see where the problem lies, or, better yet, to get SDD and related hardware, which is the official Jaguar diagnostic system.
If you don't find the fault, the car will always behave the same way, and deflating the air suspension "manually", like you did, will not help.

The suspension has to be calibrated via SDD.

Best regards,

Thomas

 

I agree with Thomas-S. If you plan to have a working air suspension you will need and use SDD intensively!
You can't just randomly replace parts and expect things to work.
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When you're deeply involved in the suspension system, you need to calibrate it, as others have mentioned; your car simply doesn't know its height. This is the first step, and it costs nothing except a cable, the SDD, and some training. If that doesn't help, you'll need to look further, but start there, or maybe someone locally has the equipment you need, because living with an old cat without the SDD doesn't make any sense, haha

 

THANKS Thomas, Clubairth1, and PeterX358. I bought a new TopDon ArtiDiag Pro scanner (bi directional). It has Suspension diagnoses and height reset chapter. I tried to reset however it was not successful. The scanner found several DTCs, C2780, (ECU in manufacturer sub-state), C2302 (Leveling Plausibility Error), B2139 (Data Mismatch), U1262 (SCP (J1850 Communication bus fault), B2162 RT. (Side Module Invalid Identification), P1582 (Flight Recorder Data is stored). Where and what SDD do I need? I'm not a Jag mechanic however I am an aircraft mechanic. Can anyone tell me how to verify the four height sensors are good. This car has four. The previous owner may have taken the car to shops that screwed much up. He did not want to drive 3 hours to Louisville, KY. and spend nights in a hotel and spend thousands so he sold the car. What is the proper size of ORings for the Valve block and 4 new Bilstein Struts air hose connection.The compressor is almost new. Car has 107,000 miles. Car was not driven for a year or so.

 

This is where I got the SDD: https://www.jaguarforum.com/threads/...ost_id=1101712

 

Let's start with SDD.
The versions that are most common for our car are V118.5, V125 and V131. It seems that alos newer versions work because they switch back to the older mode when they detect our cars, but I have no personal experience with this. There are various threads in the forum about SDD/WDS (that's the older name).

Additionally, you will need a Mongoose cable (or a clone) or a VCM, which is the interface used by Jaguar (and also ny Ford, Mercury, Lincoln and Mazda), plus a stabilized power supply capable of 50A at 13.8V. A normal charger will not work, as far as I know. The reason is that when using SDD, the car will "switch on" all electronic modules and using between 20A and 50A, and you can imagine that the car battery will not last long.
BTW, the car is extremely sensitive to battery voltage, in any case, so you always need to have a good battery in it, otherwise you will get lots of DTCs that seem unrelated to the battery, but in the end disappear when the voltage is right again.

You say that your code reader has a calibration feature, but I don't know whether it additionally has the capability of deflating and inflating the whole suspension system, as SDD has.

And that's where we come to your problem. I had a similar issue with my car last year, albeit only at the rear. During a trip to Italy, all of a sudden the car went to maximum height at the rear. As I could not return to base to get another one of my cars, I continued the journey, and the ride was not pleasant at all...


I had my iCarsoft code reader with me, as I always keep that one in the car, and in the beginning it only gave me the C2302 level plausibility error. Only after a few cycles of having the light on in the dash, reading and deleting the DTC (always C2302), finally an additional DTC, namely C1885 (Rear right height sensor - open circuit/short circuitto ground) came up.
So, faulty height sensors have specific DTCs, but it seems that they do not show up immediately. I have attached the list of DTCs for yore reference.

After replacing the faulty sensor, I wanted to calibrate the height of the suspension (I use SDD V125 most of the time), but failed miserably in the beginning because SDD told me that the car was out of range for the calibration process. Here the SDD capability of deflating/inflating the whole system (or parts therof) comes into play, because after using this feature (and not having to disconnect any lines at all) I could ,finally, successfully execute the calibration process.

I hope that this can help you.

Best regards,

Thomas

 

Thomas, My scanner does have the capability of inflating or deflating each individual air strut. I haven't successfully done that just yet however today I may. The previous owner told me he never had any suspension problems until he had a garage install 4 new Bilstein struts, and a rebuilt compressor. Now since my purchase I took the car and had 2 rear tires installed. The car was even higher in the rear after that was accomplished. My TopDon scanner allowed me to try and reset the ride height however it did not take. The scanner told me to push the reset button on lower left of the instrument panel and turn on the key within 3 seconds and then push the trip button on end of turn signal stalk and hit reset again, if I remember correctly, but the message center was suppose to state a message (reset available) or something like that, but never displayed any message. I went through the process measuring ride height from center of the wheels to the wheel arch, (twice). Nothing changed. I tried again later and when I measured the ride height the scanner would NOT accept my measurements, (out of range) I tried to falsely enter a lower height and the scanner would accept the lower value. Perhaps I should have tried to deflate as you did. I may try again but I expect I need that message to be displayed on the message center before my height reset will be successful. Thx again for your help.
By the way your car looks to be the same color as mine, however your front is lower. Ha Thanks for your interest in helping me. I appreciate your thoughts and information.

 

Again Thomas-S gave you great advice. Now lets make sure you understand SDD is a huge project in and of itself.
Here is a quick search I did and note it returned almost 400 threads!
SDD Threads

IF you want to do this and I think you do. Plan on getting a working setup. Topdon is a great line of scanners but many times SDD is the answer. All of us have multiple scanners and I admit to staying away from SDD unless it I just have to use it. My other devices are simpler and much quicker to use.

My suggestions after MANY hours of SDD use.

1. Dedicate a laptop JUST for SDD. If your like me you will need to wipe and reinstall this one or more times!

2. Don't use a VM BUT there are guy's that have got SDD working this way.

3. You will need to decide on the OS. I have used XP, Win7 Pro and now I am using Win10 Pro. So again with SDD there is not one way to do things. Many paths to success.

4. NEVER run SDD unless the laptop is plugged into AC power.

5. NEVER run SDD unless the car in on a low ripple DC power supply with at least 45 Amp rating and do note this is NOT a battery maintainer or charger regardless of the brand and the claims made for it. This I believe is the number one cause of all the SDD disasters as people just don't want to hear this. Well I did not either (at first!). My DC power supply has been measured as supplying over 30 amps for hours at a time when using SDD. I run an Iota-DLS-55 with 55 amps of CLEAN regulated DC power.

6. There is a ton of documents you will need to find and download to help you with SDD. My SDD folder after all these years is almost 20 GB. I am running the latest version which is free from Jaguar. V167.

I like to post this link to our friends across the pond on the UK Jaguar forum. That is another great Jaguar forum. The problem is they mainly have Diesel versions which were not imported to the US. So lot's of talk that does not apply to your car. BUT they have a great member called "The Mind Buddah" he has done a HUGE amount of work building "images" of many versions of SDD. Yes you will also need to decide on this and it's not real clear either. But with images wiping and reinstalling is a breeze compared to how I did my first SDD install from the multiple individual files.

SDD Images
Some can't find the download link because of how large that thread is so here is the direct link to all his files and it's probably worth downloading most if not all of the files.
SDD File Location

One last request and this is from the forum moderators. SDD is so huge that it's spread out all over the forum. They request that you add to the existing threads because there are so many of them out there already.
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As for the codes, the best thing to do with a car you just bough is to delete them. Just worry about the ones that come back, if any.

My car must have had 100 DTCs in it when I bought it, enough that I wondered for a second if it was safe to drive! Just cleared them all. A very few came back, of course the C2302 was one of those. I've ended up installing coilovers as when I disassembled the compressor for repairs, the desiccant chamber was actually a water tank, so I knew there was water throughout the system. The outlet valve in the compressor was rusted solid, so I simply threw in the towel and got steel springs. The car rides better than it ever did, and no worries about height. I never got SDD, I have a decent code reader but I can't do any programming to the car. Don't care. I do care that I can drive the car without waiting for it to un-sag every morning, and that it goes all day (instead of 15 minutes) without an air suspension fault message on the dash.

But like I said at first, clear the codes and don't worry about them work any that appear after that, because you know they're current. Stored codes may have been addressed 15 years ago, you just don't know.

 

I appreciate your info, whooshee and clubairth1. Frankly I hesitate to invest so much in equipment trying to solve this one problem. The code reader is saying there is a CAN error and lost communication with the suspension system. I don't really know how to tackle that problem and the code reader doesn't inform me. I don't have any other Jag except a 1987 XJS and have never needed a scanner for it. I've been taking every ground terminal I can find loose and cleaning and retightening. None have looked bad and none have helped. Thanks for any insight you may have.

 

Hi @swift ,
Congrats on your purchase. I normally don't advocate for replacing the air suspension, but in your case you might consider it. It will be a permanent solution to your issue, which will never trouble you again, and allow you to enjoy your wonderful car. It will also save you a lot of time and effort in troubleshooting the suspension components. However, it would also be a bit of a shame since it sounds like much of the components have been renewed.

-j

 

I have to agree with @Jacuar . There are several good versions of coilover replacements out there. Just get one with a module that cancels any resulting suspension codes. I used Motorcars LTD, Black Dog conversion many years ago on my 04 XJR and was completely satisfied. Wouldn't hesitate to do it again. I do have SDD, but since I have only used it one or two times, I'm afraid I might brick the car with it. That is a professional tool for a reason. Good luck either way.

 

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By the way your car looks to be the same color as mine, however your front is lower.
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Sorry for the late reply...
The colour of my car is Quartz.
Regarding the front, it actually was at the regular height, but with the rear suspension at full height when I had taken the picture it looked lower.

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Frankly I hesitate to invest so much in equipment trying to solve this one problem. The code reader is saying there is a CAN error and lost communication with the suspension system. I don't really know how to tackle that problem and the code reader doesn't inform me. I don't have any other Jag except a 1987 XJS and have never needed a scanner for it.
Unquote

If you plan to keep the car, in the long run you will be happy to invest into SDD, it will help you with different problems that might occur. My car appearanty also has some CAN errors. Interestingly enough, I have never noticed any problems while using thecar, everything normally just works.
A 1987 XJS is not comparable to an X350. Although the use of some electronic control modules started at the end of the 80's, and you could already read some basic fault codes with some pretty basic devices (you needed lamp and counted the number of "blinks"), the XJS basically is a 70"s car, and, although updated during the time of manufacturing, the electronics are a different world from an X350.
The use of scanners became serious by mid of the 90's...

Best regards,

Thomas

 

I calibrated my X350 some years ago with SDD. It was quite easy and worked on each run. You can also "lie" to the car to make it higher/lower, then default. (But I wouldn't recommend.)
SDD also allows to plot the measured height of all 3 or 4 sensors. (3/4 depends on car's age).
Does the reported height read correct values ?

Although air suspension (and adaptive dampers) can cause more trouble compared to coilovers, CATS is one part that makes riding the car unique. At higher speeds, it feels like riding the magic carpet.
I missed that feeling when testdriving a X351 pretty soon.