I recently got a '04 XJ8 that had been involved in an accident, nothing seriuse, the major issue was the wire harness that run behind the passenger fender got nicked pretty bad and shorted out almost everything in the car.

So I got to work with my solder iron and shrink sleeves and repaired all 100 wires to perfection, and I mean that, perfection.

Now everything in the car is fine, have been driving it for over 300 miles since with only a few issues; one of them being a trouble code C1175 - LH Rear Wheel speed sensor, so I got me a new sensor and replace it, check engine light went away.

Only I had an issues with the replacing of the sensor, the bolt corroded so bad that it snapped and left a piece inside which I could not get out, I tried heating it and grabbing it with a vice grip. No luck. So i used some kind of epoxy and mounted it around the post that was sticking out and secured it down.

Fine, I got my traction control back, and the ABS light stayed on, but after driving at 3mph for a few seconds it went away as well. but after going of 20-30mph both traction and abs lights came back, but no check engine.

Now here is the real strange part, since I replaced the sensor, though I am not absolutely sure, both front suspensions went all the way up and would not come down. I checked the height level sensors and they are fine and in the right position, but for some reason the went up, as high up as they can.

Another thing I noticed was that the compressor would go on at speeds of 30-40 and when I'd slow down I would hear it release some pressure and stop operating.

Funny thing is that I do not think that there is any leaks in any of the bags.

So I went over the harness again and there is nothing there to suggest it is a short.

So my question is can the speed sensor be related? And is there some kind of air suspension reset in the car?

Thanks in advance for any help!

 

This is very difficult to say, especially given the accident. There are several sensors that feed the Air Suspension Module (ASM) - hieght sensors; accelerometers; Engine RPM; Speed sensors (which come from the wheel sensors); on and on. any one of a number of related sensors could have received a non-fatal blow from the accident, but might only be failing now.

Bottom line, the system is sophisticated and fragile and subject to failure under normal conditions. The accident exacerbates the situation. I probably couldn't get this one w/o a WDS. The wire harness concerns me the most.

Sorry, I know this isn't much help, except maybe to encourage you to have it diagnosed; otherwise, you're going to chase a lot of very expensive sensors and modules.

 

Thanks for the response, and yes, I figured that given the cars level of sophistication it would not be a simple problem and solution deal.

Though you have given me some more direction in where to look. First I bought a drillbit set to drill out and rethread the hub where the speed sensor mounts, so ill try to have that clamped down by tomorrow, and that would be one less area of concern.

But you mentioned a 'WDS', what is that?

 

Jaguar's computer diagnostic equipment, read about it here.

 

Above a certain speed, the air suspension is lowered by the suspension control. The input for this will come from a speed sensor somewhere, I assume the same one that drives the speedometer.

It sounds to me like your accident damaged more than just the wiring loom. Other thing is to not "cobble up" the speed sensor as you describe. You really need to restore the car to as-built state as far as possible.

 

That being 100mph!

On the X type code c1175 usually happens when the reluctor ring on the outer cv joint corrodes and falls off.
Im assuming its the same on the XJ and therefore the reluctor ring may be at fault meaning a new outer cv joint.I stand to be corrected though?

 

When I replaced the sensor I checked out the end of the axle and it all looked good, so I dont think that is the culprit.

One other thing I failed to mention is that there is no 'Air Suspension Fault' message in my speedo cluster! It only comes up when I driver for over a few minutes at high speed, and a simple shutoff and ignition makes it go away. Dont know how relevant that is.

 

Now here is the real strange part, since I replaced the sensor, though I am not absolutely sure, both front suspensions went all the way up and would not come down. I checked the height level sensors and they are fine and in the right position, but for some reason the went up, as high up as they can.



Hi,

Let me take another bite on this apple - regarding the front suspension extending to its fullest position, this can be caused by a couple of things I can think of in theory and I am trying to weave in the extenuating circumstances of the accident, small as it was but, nonetheless, damaging an electrical artery.

First, the front sensors are basically rheostats (variable resistors). When the ASM is in setup mode, the front suspension is set (toggled using the WDS) to the desired height, then the voltages from the 2 front sensors (on an 04) are read and stored as reference points by the ASM. Something has to be faulty with the stored reference values for the ASM to allow the suspension to reach full extension, possibly a corrupted code, because the ASM is no longer using the reference voltages, or they somehow got changed (as in a damaged and shorted out harness that possibly supplies the ASM). There is no condition I know of in any of the phases of ASM function where the FRONT suspension fully extends. Not the case with the rear. If the front end is lifted w/o the rear, and a functional suspension system, the rear will raise fully trying to match the front travel until it runs out of extension.

The second possibility is a faulty distribution block in the trunk, but then again, if a valve stuck in the distribution block, the ASM is going to constantly be trying to adjust the fully extended front suspension while the distribution block is stuck opened....Hmm....I'm changing my mind about this one because I don't think the compressor would have lasted this long in a constant struggle for up and down.

Regardless of any of this theory, something is going to have to recommand the ASM with the proper height voltages from the front sensors, and a WDS is the only way I know that can be done.

Can you tell me anything more about this single condition? Does the car aver relevel? Or, is the front suspension constantly fully extended?