While I finally load some software to my laptop this week I thought I’d throw this rather omni-present issue out to all for a little mulling over.
I’ve driven this 2005 XK8 a little over 3K miles since Aug.



Initially it would occasionally show the dsc fault, maybe 30% of the time.
The dsc was on one day when I took the car in for some rear tires, when I picked it up the dsc fault was not present and it remained like that for @ 200 miles. Spurred on I pulled the rear wheels and inspected the speed sensors, they were clean and tested okay…didn’t measure the cable resistance/continuity. No change however, the dsc fault continued to show up now and then. Within the past 500 miles the dsc is always on.

abs fault+no cruise would always show up when I drove on moist surfaces (light rain would spur it to rear its head) and occasionally it would just show up.

I have a rear bearing going out and was wondering if the extra slop could be playing havoc with the speedsensor and leading to one or both of these issues.

It appears that the abs module was replaced at some point, but that certainly doesn’t preclude the possibility of it currently having an issue.
These cars sure are fun…I used to need several german cars to keep me occupied, now I find that only one Jag is more than I can handle.

wj

 

My ABS-DSC will sometimes come on when I reverse and make a sharp left turn. Probably a loose wire on one of my front sensors but it always clears and I've checked everything.

Little electrical issues like this are what drives me crazy with these cars!

 

Well, today it was 82 degrees(f) and the xk8 was asking to go for a run in the sun.
Of course I had my dsc warning but we're getting used to each other. I stopped at a stream and spoke with some folks out fishing. On my return to the car I hit the panic button on the remote by mistake, made a lot of noise, turned it off and casually (with red face) got in the car. WOW...no DCS fault warning! Drove 20 miles and shut it off. Came back a few minutes later and started it up...no DSC fault light! Just for the heck of it I shut it down once more and restarted...still no dsc fault.
Maybe it appreciated the nice weather today and rewarded me with no christmas lights. I don't expect the lack of dsc fault to last for long but who knows...this car just amazes and entertains me.

wj

 

Your wheel speed sensors may look clean but keep in mind they can be quite sensitive to any contamination. I would pull them and scrub them just to be sure. And while you're there, take a good look at their wiring harnesses. The rubber insulation boots tend to split and crack, allowing moisture inside the wiring. I carefully cleaned them up, then applied a liberal coating of neutral-cure silicone sealant and allowed everything to cure overnight before reassembling. That was in March 2013 and since then, my wife (it's her daily driver) has never reported another instance of the ABS/DSC warnings appearing on the dash. I continue to scrub all four wheel speed sensors at every oil & filter change / tire rotation (6,000-mile intervals) just for good measure, and I continue to apply more neutral-cure silicone sealant on the wiring harness boots as needed (maybe every 18 months or so)....

 

As you say, this is just a guessing game until you can run diags. I'd focus on getting that running.

 

Yes of course the most efficient way forward is via the software/reading
I look forward to what I find.

I just drove @ 90 miles today, in the rain. The dsc and abs warning lights never showed up. If this continues much longer I'm going to conclude that somehow the alarm going off and being reset yesterday forced some sort of reset of the logic.
The early Ford (circa 1996) engine controls would continually learn and adapt to different 'base' look up tables. If one bought a tuner it was possible to set some different thresholds which dictated when a fault was sensed. Who Knows! I really do like the car, it drives great and is so entertaining.

wj

 

The benefit of so-called wheel speed sensor "cleaning" probably has nothing to do with "cleaning" and everything to do with demating & remating the connector, which exercises the pins & sockets. The sensors work due to electromagnetic (EM) coupling between the sensor electronics and the rotating teeth on the hub. The EM coupling "sees" right through the plastic housing of the sensor and surely through any dirt, too. What matters is the distance between internal pickup and the teeth, which is the same whether clean or dirty. I had a sensor issue and swapped left to right. I "cleaned" them based on these forum postings, but they weren't dirty. I believe folks will find that simply demating and remating will provide all the benefit being credited to sensor cleaning.

 

These sensors do in fact get grimy and dirty over time. Whether causing them to function again is a result of the toothbrush scrubbing, the de-mating and re-mating of the sensor, or a combination of both, I will continue to perform my scrubbing ritual at every tire rotation....

 

+1 to Mark.

I found that the leads to the front sensors were too short and this was causing the fault to appear in reverse turns, as Jon89 described. I also would get occasional faults in the rain (exactly WHEN you need ABS! - lol). As Mark said this was from the connectors getting fouled.

To resolve these problems, I cut the tie-wraps and moved the front ABS leads closer to the wheels for a little more slack, I ever so slightly bent the pins in the connectors so as to promote better contact, and I filled the connectors with dielectric grease when I put it all back together. Haven't had an ABS or DSC fault in a two years.

BTW: As Mark said, when you take your sensors off to clean them, it could be that just the act of replugging the connector is what made your problem go away for a little while. That's what was happening to me until I "Broke-the-Code".

 

I had once client who changed new 17" tires to front, only.

Same symptoms. Was fixed after he installed also new rear tires.

car is clever enought to "think" there's slipping due different rotation speed of rear and front wheels..

 

Thanks for the alert about tire size effect on ABS. I changed tire size when replacing front tires based on availability (lower profile and wider, kept the overall height about the same). I didn't have a problem, but I'm going to remember to be careful about this point.

 

Occam's Razor - the simple solution is the most likely. How old is the battery? A lowish battery and a cold engine with consequent heavy cranking current draw will often prompt a DSC error as my 2005 XK8 often does. Warmed up with less viscous oil - no problem. Check this first before worrying about anything else and no, as a past owner of several BMW, Porsche's and Mercedes these are not more problematic despite the opinions in the popular press. YMMV.

 

Even easier, is to just wiggle your ABS sensor connections a little and see if anything changes. You don't even have to take the tires off. Just reach around. If anything changes (especially for the better), pursue that fix first.

 

If you have an intermittent ABS/TRAC fault, disconnect the main connector from the ABS module and check for shorts to ground on each pin. In some cases shorts may only occur under specific ambient conditions (extreme heat, cold, wet, snow, etc).