Hello all,

2006 Super V8


The car was put in a ditch (not by me). About a week or two after that the back went way, way up. That was a few weeks ago and I hadn't gotten to it yet. Just the other day the front went down and I got the “Vehicle Too Low - Air Suspension Fault.”


So now that it's not drivable it's time to get into it. Since the back was high I didn't think it was the compressor but here are the steps I took so far:


Let the air out of the back by loosening the L/R hoses on the Solenoid Valve Block and then re-tightening them.


Loosened both the L/R front hoses at the shocks to confirm it was holding air, it is and I re-tightened them.


Disconnected the battery in the hopes of rebooting the system like my computer or phone sometimes needs.


Asked for divine intervention and promised to be a good boy if the reboot was all that was needed.


Stated it up and nothing – so much for divine intervention. So now I have a low rider at all four corners. I'm thinking that the compressor failed when the front shocks when down and the reason the back stayed high is because the solenoid valve block acts as a one way valve not letting the air escape until receiving a signal from one or more of the sensors. (I don't know if that's true.)


So what are your thoughts? Is it the compressor, and if so is there a way to test it to confirm before I replace it? What caused the back to go up so much in the first place? (assuming that problem will persist if I fix the compressor.)


I've tried to read all the related posts on here regrading the Air Suspension system. And, no, coil shock replacement is not an option. I did notice a few discussions about fault codes and there being a scanner that would read specific Jaguar codes, something way beyond what Auto Zone or O'Reilly's can give you. Someone said it was expensive but didn't give any particulars. How much and where can I get one. Is it worth it?


Thanks for any thoughts you have.


Kevin

 

Not an S-Type, I suspect, so wrong forum.

 

I wonder if it went into jacking mode when it went into the ditch or possibly a height

sensor was damaged.

If possible try driving it around for up to 20 mins max.

 

Hi Kevin,

I have moved your post from the S-type forum to the forum for the X350, which is the Jaguar factory code for your 2006 Super V8. Here you will find owners of similar cars who will be happy to try to help.

The first question that comes to mind is: did both rear corners raise up equally, or did one side raise up higher than the other? I'm wondering if a height sensor was damaged in the accident and is telling the Air Suspension Control Module (ASM or ASCM) that one or both rear corners needs more air when in fact it doesn't.

It is possible that the valve block in the trunk was damaged or that one of its electrical connectors was slightly dislodged, so it would be worth disconnecting both connectors, cleaning them with zero-residue electrical contact cleaner and allowing them to dry then securely reconnecting them.

The front end lowering could be due to an air leak in one of the air shock bladders, perhaps due to the impact the car suffered.

My first reaction is that your issues don't sound like a compressor problem, but you can test the air compressor by jumping the appropriate terminals in the socket for the Air Suspension Relay, which is Relay 1 in the Front Power Distribution Fuse Box. Glancing at the schematic, it looks like jumping terminals 3 and 5 in the socket should make the compressor run.

It would definitely be helpful to interrogate the system for any stored Diagnostic Fault Codes (DTCs), which does require either a dealer-level system such as SDD, or a high-end third-party scanning system such as Autoenginuity with the extra Jaguar module. Search the forum to see how many members have acquired SDD and set it up on a laptop.

Hopefully other members will offer some helpful suggestions.

Cheers,

Don

 

Don,

First, my apologies for posting to the wrong Forum. I saw Supercharged V8 and went from there...

Both rear shocks raised all the way up at the same time. Seemed unlikely to be an individual sensor or shock. Same thing with the front, both lowered at the same time.

It wasn't really much of an accident. Just far enough off the road and into the mud that it needed to be towed. The trunk, and all the components including the valve block and reservoir tank are pristine. I did disconnect the reconnect the two plugs on the valve block as a matter of course. Ninety percent of all electrical problems are bad connections!

Yesterday I checked every fuse and relay (engine compartment, cabin, and trunk), but I'll trace down that relay and see if I can get the compressor going.

Also, I'll look for that scanner now that I have a name.

Thanks for your input.

Kevin

 

I didn't have any success yet, I still have a low rider, but I did manage to identify the relay, confirmed again that it was working but I understand that the car has to be moving 18+ MPH for the compressor to kick in.

I jumped posts 3 and 5 (on a 4 post relay - go figure) and I could hear the compressor working. Several things I noticed, 1) nothing was happening with the height, 2) the jumper wire was getting awfully hot after about a minute and as an aside, 3) just starting the car required a foot on the brake. That is intermittent, sometimes you do and sometimes you don't, weird. Also, not that it matters now but does anyone know what those 9 relays are for in the engine compartment fuse block? I now know that R1 is for the Air Suspension System but I can't find a comprehensive list anywhere. I don't have a relay in R3 and the slot looks like it has always been empty. It would be nice to know what they are for.

Because the wire was getting so hot and I had read that it should only run for 2 min. max I let it cool off. Then it occurred to me that just because the compressor is making noise doesn't mean it's pumping air. Because it is much more accessible, I disconnected the supply air hose from the valve block in the trunk, jumped the relay again which ran the compressor and yep, getting air from the supply line. It is not a great deal either in volume or pressure but it is working.

I'm guessing my next step is to confirm that the valve block is letting the air into the reservoir. My only way to check that is to disconnect the hose at the reservoir or the same hose at the valve block. As I was disconnecting that it was pressurized so it was either new air the compressor had just put in there or left over air from when it was working. I thought I'd ask about the valve block before I empty it out. Is there a way to check the valve block both mechanically and electrically?

Much like tricking the system by jumping the relay, is there a way to bypass all the sensors and just put some air in the system and leave it that way without the constant adjustments by letting air out and putting it back in while on the road? I only ask that because I would like to use the car while I get to the bottom of this. I'm thinking if I do manage to get some air in the system and get all 4 corners up I could disconnect the plugs on the valve block and leave the relay out. Make it an isolated system. Any thoughts on that?

Thank you for any input you may have.

Kevin

 

Hi Kevin,

First, I think you will find the document at the following link to help you understand the design and operation of the air suspension system, which may answer some of your questions, including when the compressor will and will not run (you bypass those commands from the ASM when you jump the Air Suspension Relay, since battery voltage is always present at terminal 3 when the ignition is on). The document is the Air Suspension section from the '04 XJ New Model Dealer Training manual, which is the most complete system description I'm aware of:

http://www.mediafire.com/view/7rdkgg...on_Section.pdf


Second, the relays you asked about are all identifed in the X350 Electrical Guide. I think the Captain Jaguars link is still down, so send me a private message with your email address and I'll send you the manual in pdf form.

Third, it would be prudent for you to have the X350 Workshop Manual, which can be downloaded from this forum in six sections:

http://www.mediafire.com/download/md...f+contents.pdf
http://www.mediafire.com/download/aa...nformation.pdf
http://www.mediafire.com/download/n3...2.+Chassis.pdf
http://www.mediafire.com/download/9b...Powertrain.pdf
http://www.mediafire.com/download/0i...Electrical.pdf
http://www.mediafire.com/download/4j...+and+Paint.pdf


Regarding your question about pressurizing the suspension and then disconnecting the valve block and air suspension relay, I don't think that would work for long since the pressure of the air changes with ambient and operating temperatures, and some air loss is inevitable over time. However, if you could get the system pressurized you might be able to at least drive the car for awhile.

Since your compressor is providing at least some pressure, and the reservoir was pressurized when you disconnected its hose, I share your suspicions about your valve block. But since the problems may be mechanical or electrical, it's probably best to have the fault codes read before you start blindly replacing parts. And the Electrical Guide will help you know what you can test in terms of voltages at various points in the system.

Cheers,

Don

 

Good advice to get the fault codes read. My money is on a duff or displaced height sensor, maybe a fault with the connecting wires. The car always tries to keep itself level. The rear wheels are controlled individually one sensor per wheel, the fronts together one sensor only.

Has anybody examined the car up on a lift to assess if there's any damage underneath ?