That sounds exactly like dirty sensors, although it could be the solder joint in the abs module or a weak battery, too. Cleaning the sensors is the place to start. Maybe you can set the new speed record.

Actually, now that I think about it, it sounds more like a battery issue. It's happening right after you put a heavy load on the battery with the starter, and it's apparently not happening in the middle of a drive. Take the car to Autozone or someplace and have them load test the battery. The testing is free.

 

Thanks Sam. Will have it checked. What readings would warrant having it replaced? What's a good brand if I do?

Setting a new speed record, I can't say! Great tutorial!

 

I'm not sure about the reading on the battery. The auto parts store hooks up a special load tester to it and the load tester has a little needle that points to red, yellow, or green. At least that's how they worked back in the old days.

 

If the problem turns out not to be the battery, here's another possibility that fits the symptoms:

The ASC/Trac warning does not appear when you first start the car, correct?

OK, then you back out of the driveway and ... turn the steering wheel pretty hard to one side or the other ... and then you get the light? If this is the way it plays out, there's a known sensor wiring issue we can talk about.

This system sure is a PITA.

 

I'll watch it next few days.

 

Yes! This is when my warning lights go on... when backing up/turning is involved - just the scenario you describe. My sensors are now clean, and I've had my ABS module rebuilt. My mechanic is wondering if the wiring harness may be the culprit. I'd love to hear your thoughts, Dennis.

Walt

 

Walt,

It seems in some of our cars there is not enough slack in the wiring harnesses leading to the two front wheel sensors. So, when you turn the steering wheel a large amount, one of the harness connectors gets stressed and goes open-circuit temporarily.

Once the ASC light clears, the problem doesn't reappear until the next big steering wheel movement.

The fix is to cut the plastic tie in the wheelwell that secures the harness, wiggle things a bit to make some more slack, and then re-secure the harness.


The following stuff I lifted from my own post in another thread here. (Is there a way to reference a specific post? I'm missing it if so.) Note that if yours really is the "wiring harness slack" problem, you should get normal readings with the wheels pointed straight ahead, but you can probably see the fault with the wheels turned full left or full right.)

------------------------------------------------
If cleaning the sensors does not help, there is an easy way to distinguish between a "box" problem and a "wheel" problem and, if the latter, to figure out which wheel is in trouble. The first thing to do is open the big 25-pin connector at the ABS box and test resistance to the wheel sensors. The connector pins involved are these ("live" sensor pins first, sensor ground pins second).

RF: pins 3 & 4
RR: pins 6 & 7
LF: pins 17 & 18
LR: pins 21 & 22

There is a helpful picture of the connector layout on page 26 of the JTIS electrical guide (at least for MY '01). *** The image shown is of the male side of the connector. Picture its mirror image to "see" the female connector, which is where we measure. ***

Readings of ~ 1k ohm on each sensor are normal. If you get one wheel way off from the others, you have more than likely found the problem, or rather narrowed it down to the wiring and sensor for that wheel.
--------------------------------------------



Good luck and keep us posted,

 

THANK YOU, Dennis! Very helpful. I'll definitely check out your suggestions and report back. Really appreciate your generosity in presenting so much detail in your post.

Walt

 

Sam - Thank you very much for this DIY ! I've had the same ABS/DSC intermittent fault warning randomly for about the last month or so and was wondering about taking it in. I was able to get mine off/cleaned/reassembled in about 40 minutes or so. I didn't have to pull the wheels - fronts were easy to get at with the wheel turned fully to the side, the rears I could reach/feel thru the wheel & over the brake disc - now that (thanks to you !) I knew what to look/feel for.

I just drove around for a while, stopping/starting etc. and no faults !!! Yesterday I would have seen it 2 or 3 times. We will see as time goes by but I am pretty confident this did the trick, so thanks again !!!!

PS - you are also correct the rears were MUCH dirtier than the fronts.

Vinnie

 

Hi
This is really useful, and incidentally, your post is the reason I found this site at all.
Thanks for taking the time to do this.

Cheers Mike

 

To dennis, if you take your cursor to the # post (for instance #27 where you talked about the pins) that 'link' will actually be your individual post (not a thread, just your post). You can copy the link, just like any thread or internet address.

 

H20boy,

Aha! Thank you sir.

 

Very well done. I do not have an intermittent light, but it seems to be a very sensitive system, with the light coming on with very modest acceleration,crossing a manhole cover in the rain. Is this normal? I am waiting for any possible snow with trepidation, as an overprotective traction control can be worse than none at all, in my opinion. Your thoughts?

 

Yeah, it's a pretty fussy arrangement. Three common, distinct failure modes that I know of: an open solder joint in the electronics box, dirty sensors (though honestly I do not really understnd why this should matter) and wiring harness problems.

These lights you're getting ... just the momentary "ASC" rather than "ASC unavailable"? If so, I'd say sounds normal. There is a steep, sharp curve I travel often which sets it off more often than not.

 

Thanks Dennis, I just get the ASC light, no unavailable message. I had a Mazda minivan with TC, and I honestly found it more of a hindrance than a help, to be honest. I hope the Jag isn't the same.

 

Just an update...No further warnings or lights the past two weeks, and have been backing out and manuvering as in the past. Maybe it was the heat of late summer!

Bound to come on today for sure! haha

 

When this issue occurred I went to bed thinking about just how much money I had to put aside to repair this issue. It nagged me all night because taking a jag to the dealer is not cheep and it is the only place I will trust for major repair. When I bought this Jag money was not much of an issue but now every I have to make every dollar count. I am so glad I did some research before I called AAA to tow my baby to the dealer. So after about three hours of work, because I had to do the first wheel with great care because I did not know what to expect, I am a bit stiff today but my baby is running fine and I am so grateful to this thread as it saved me a lot of money in just diagnostic cost alone not to mention my time. This repair cost me three hours of my time and the purchase of a $10.00 ratchet.

https://www.jaguarforums.com/forum/s...ad.php?t=37434


resting now...

 

Ifexsa
Glad to hear everything went smoothly for you, don't give up on any other fixes most are doable. Just follow most of the directions for the fix, they are not that complicated. You would be surprised at the amount of money you can save.
Doug
2001 XKR Silverstone

 

I'm glad I was able to help, Ifexsa! This fix was without a doubt the simplest thing I've done on my Jag, and it got rid of that irritating DSC message. This forum is awesome, and you'll find lots of other helpful tips here. I hope you stick around. Go check out the "Off Topic" section.

(and by "Off Topic" section I mean the "girls on cars" thread.)

 

I am wondering if this is why I can never tell any difference with the Automatic Volume Control on my radio/CD player on, in that it is suppose to raise/lower volume according to speed. I'm going to clean mine and see if that makes a difference. However, I have not had any of the brake or traction warnings or clicking sounds. Hope to get to it by this weekend, if not sooner.