Hello to all you ABS experts!

After doing a search and reading and acting on all the posts on ABS/SC Fail, I've still got a problem. Let me outline what I've done:

About 3 months ago, my ABS/SC lights lit up on the dash. Never had it before. After reading some posts, I went to check out the speed sensors and the wire on the left front sensor had corroded and totally disconnected. Fixed it; checked all the other wires and for good measure, cleaned all the sensors as I went.
The light went out and stayed out for 3-4 days.

When they came back on, both the ABS and Stability Control Fail came on. Upon turning the ignition off for more than 10 minutes and starting her back up, only the ABS light came on and turned off after driving 50 yards.
Upon the next shut down and restart, no lights would come on. Sometimes there were no lights for 1-2 days. Then, either while stopped or driving, both lights would come on again. The cycle has been repeating itself this way ever since.

I took off the ABS module and re-soldered the 2 posts which appeared to need it. No lights for 3 days. Then they lit up at a stop sign and the pattern has been repeating itself as described above ever since.

I have had a multimeter that I never learned how to use, so I pulled it out, watched some YouTube videos on how to use it and went out and followed Gus's guidelines in his "Jaguar XK8 ABS 'Hard Fault' Check List".

I checked all the fuses and they were good.
Then I checked the resistance in all 4 wheel sensors at the ABS multiplug. Each one of them read between 1.07-1.09 kohms instead of 2.00-2.20 kohms (which is the recommended # given in the checklist). There was no one sensor that read lower than the others. Is this normal? Why would they read this low? I also find it interesting that my readings are exactly one half of what they should be.
Now I must admit, the probes of the multimeter would not fit into the pinholes on the ABS plug so I used a small bit of copper wire and stuck one end in the ABS module pinhole while holding the other end to the multimeter. Would this make a difference?
I realize that life would be easier with codes to read, but my code reader doesn't do ABS codes and Jaguar wants $125 just to pull the codes...so I differ to all of you ABS experts.
What's my next step?

Nick

 

Nick,

Your resistance measurements: sensors are surely OK, there is an MY difference with some years being ~ 2k ohms, some years ~ 1k ohms.

The static resistance test will often not pick up a common problem ... an intermittent connection to one or both front sensors. Two common causes for this ... stress on the connectors at the sensors, or a wire break within the last section of wire leading to a sensor. Often this shows up following a big steering input or large amount of front suspension travel.

Even without jacking the car you can open, clean and re-seat the connectors. If this buys you a temporary fix, I would then look into rearranging the wiring leading to the sensors. There are some plastic ties on the control arms you can cut, then move the wiring a bit to increase the slack, and apply new ties. I've gotten long-term fixes on two XK-8s this way.

Good luck!

Edit: forgot this ... after correcting a sensor problem, on the next start you should have no message like "ASC/Trac not available", but the yellow ABS icon may still be lit. It will go out after you drive a short distance.

 

Thanks for the info, Dennis.

After reading, literally, every thread on the subject in this forum, I've never heard this info. Makes sense. I will check it all out tomorrow.

Thanks again

Nick

 

This is easy, remove your module again, and re-solder again.

Remove all the old solder by using a solder removal siphon(I use a baby nose ball) after heating the solder to get it wet.

Then roughen the surface of the contact points up, then apply a lil flux and re-solder with a high quality solder.Most of us mess this up the first time, all the old solder needs to be gone before you apply yours for good contact AND SO DOES THAT CLEAR PROTECTIVE COATING ON THE BOARD.


Then OHM the speed sensors AT THE ABS MODULE CONNECTOR, use 2 pieces of wire or paperclips in the holes, that way you see what the module does at the face of it.
Use this chart to find the wheel speed sensor holes on the connector, VERY EASY, TOOK ME 3 MINS
http://www.jagrepair.com/images/Auto...heet%20XK8.pdf

 

+1 on removing the insulating coating and using a little flux. I have never had to remove the old solder completely, but it can't hurt.
Use a wet q tip to clean up the flux after soldering.

 

I use a trimmed down acid brush and ISO alcohol to clean the board before and after. Its not so much getting all the old solder off as it is getting all the oxidation off so the new solder will stick. And it has to be heated up enough that you actually see it flow and not just make a blob. The flux needs to be removed as it stays sticky and will attract dust an other impurities that can cause problems. And never use acid core solder on a pc board. Something like Kester 44 (60/40) flux core ir equivalent.


Dave

 

Nick,

You're quite welcome. I can't claim anything original here though. Learned this stuff from what are now some pretty old posts.

Yes, it's possible there's still a problem in the module, but based on your description, I'd guess front sensor connectivity instead. If reseating them makes for a fix, even temporarily, then you'll know.

 

Thanks to everyone for the info.

This weekend, if it isn't freezing, I'm going to start again and check out everything that may be involved and report back

Nick

 

WOW, I am a new member and I have had similar problems with my 2000 XK8. I constantly have the messages ASC not available and Trac not available. I have taken the Jag to several shops but without success. So I have driven for over a year with these 2 messages. The diagnostics shows P1111 which is a 'gas Cap not tight' error but does not give me any indication of this ASC/Trac not available issue. I will have to try these suggestions and see if it also solves my problem. Much thanks to the forum for being so detailed.
Mike

 

Welcome to the forum. Most Generic code readers will not read ABS codes, and the description for engine codes are often incorrect. P1111 means the ECM has declared the emission control system functioning properly.

If you have the codes read by a specialist shop or dealer they will be able to tell you exactly what is wrong. Throwing parts at it will cost more than the typical one hour diagnostic charge. But come back here with the codes and the forum will help. Don't let anyone tell you the module or the sensors must be replaced.

When you have time, visit the new member area and introduce yourself:

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

 

Thanks. I did the new member post. I hate going to the Jag dealer but may be my only option to get the diagnostic codes. Everyone else near here only uses the generic readers. Thanks for the offer to help.
Mike

 

use my diagram, find your solution, case closed/now you may have to drive the car a while to clear the system.

 

Many a time here folks have said check your battery, make sure it is at optimal strength, that is no can cause squirly things to happen on these cars.

 

Hey aode06

I went through the entire process again (except resoldering the ABS module points, although I may have to do it again) and still have the lights, although not as often.

My question to you is approx. how far do I need to drive the car for the system to clear? Is it straight long distance driving or is it over a period of time?

Nick

 

Mine would clear after the 3rd time I started it after a short drive each time.


Dave

 

So does mine, Dave, then it would be fine for the next 2 startups, then the ABS light only comes on for one startup, then both again on the next startup.

Nick

 

see if it is temp related do they lights not come on if its cold . cold weather will make a bad connection in the abs module connect till it gets warm enough under the hood to expand the mod and disconnect . i bought a swap on ebay from modulerepair pros and has worked perfectly since replacing .

 

Well folks, yesterday I pulled the ABS module for the third time, went out to Harbor Freight and bought some magnifying jeweler's loops, and went at those solder points again.

Here's the key: REMOVE ALL THE PLASTIC COATING ON THE SOLDER POINTS AND AROUND THE AREA!

After looking at it under magnification, I realized that I soldered right over the coating on the points the last time. I had thought that I cleaned the coating pretty well the last time but apparently I hadn't cleaned the actual tips. I removed all the previously applied solder, cleaned the area with alcohol, and used a needle to remove ALL the plastic coating and re-soldered the 2 points with a much finer solder tip than the last time.

Stay tuned and keep your fingers crossed. 10 starts and shut downs with no ABS/SCF lights yet.

Nick

P.S. Thanks for the info, wolfpck. I never noticed where a temp change would affect the ABS one way or the other. If this most recent "fix" doesn't resolve the situation, then out it goes to the pros

 

I think you have it now. The plastic coating is often overlooked and prevents proper wetting of the solder.

 

also if you crack it open they wont touch it