abs and traction control

Hi everyone,

I have an 01 windstar with about 156k miles on it. I have had recently, intermitently, the ABS light unit come on. Also for a number of years the traction control hasn't work right, in fact I never liked it, so I always turned it off. The dealer at the time it first started acting wacky claimed more than once that everything was fine. (it just seemed to engage even when going over a small bump, intermittently) I never like it anyway, so I just turned it off. This after warranty was up and I was willing to pay for a repair.

So recently I go to autozone and by that ABS testing unit ($200), plug it into my vehicle (which shows no regular OBD II scanner errors), error messages that say ALL 4 wheel sensors are bad, and a U1262, SCP bus fault error. Unfortunately with this scanner I can't erase the fault codes, so my plan right now is to unplug battery (and have headlights on for 15 minutes), hopefully those errors are cleared, and then retest after I drive a few times. It is wintertime here in buffalo and I can see how wheel speed sensors might get plugged up, etc, but I was quite surprised to see all 4 bad...

I will also get and look at the sensors, but my suspicion is that a single bad wheel sensor will kick on the ABS light? If so I'm probably screwed and looking at ABS module. Just thinking out loud.

I suppose I'm just looking for any thoughts on this, or previous experience. Thanks!

-Jerry

I am not familiar with the traction control....I don't have that.
However....I look at it as a "reverse ABS"......in that it pulses the brakes ON to a given wheel that is spinning faster than the other.

So....with that in mind.....both the ABS and traction control use the wheel sensors.
I also find it hard to believe that ALL 4 wheel sensor have gone bad.....possible over a long period of time......but again....still not likely.

Unless you have a garage to work in......trying to work on a vehicle in this weather is crazy unless it is a very basic and critical issue (won't start......NO brakes.....coolant gushing out....etc).

The pictures that the link in my signature takes you to show my front and rear brake jobs......and you can see the wheel sensors in a couple of pictures.
There is a big toothed gear on each wheel.....and a magnetic pickup mounted that has wires going to it.
When I inspect my brakes.....I spray them down with a liberal amount of brake cleaner....and ALSO clean the gear/pickup of brake dust.
Then....I inspect the position of the sensor relative to the teeth of the gear......it is common for one to get bumped during brake or other work in the area......
It should be maybe 1/4 inch away?.....but not close enough to rub the teeth.
Inspect the small cable that goes to the sensor.....to make sure that it is intact to the small clamps that get it into the body of the vehicle.

Once you have done this......and solved any problems you may have found....if the problem still is present.....it gets more involved....but I would STILL look at the wiring and connections to the various components (and associated fuses) before putting new expensive parts in.

Thanks Wiswind I really appreciate the comments!

The van is due I think for a tire rotation, have to check my records, so when I do that I can clean off those sensors and inspect them. I especially liked the idea about using brake cleaner too! I have repaired several items on my winny, both brakes, rotors, struts and shocks, and never really looked at the wheel sensors before - learn things the hard way I guess...

I do have the Ford service manuals (from Helm), and a garage to work in, although space is tight, but it beats being out in the weather this time of year here in buffalo. Unfortunately, most of my work always seems to be during winter as that is when things go bad ha ha. :mad:

-Jerry

It seems to me you have implied that the abs light came on only when the traction control was acting up. When the abs light comes on, will it go off when you turn off the traction control? It would seem to me if this is a sensor, exciter ring, wiring problem, you should be getting the abs light on with or without the traction control on. Does the abs light come on when the tc is off? If so, your tc programming is the problem. Have you found your abs to work as it should? Wear the abs codes you got for past, stored codes like all the sensors are not working, or is that one and others existing problems? The former would seem to be something that has come and gone, though you wonder why it happened at all. The ongoing codes would concern me the most. You may be onto something with the tc being the cause to all of those codes, but you need to be sure you actually have abs.

Hi all,

Thanks tripletdaddy for your thoughts. No the ABS will come on independent of the traction control I think. I routinely turn off traction control, and have for a few years, (always felt it engaged too easily, and control was taken away from me) but have just recently noted the ABS lighting up from time to time. Once the ABS light comes on, traction control is also disabled - I believe this is default because if the abs cannot function, the traction control cannot either because the systems are tied together. So as an update:

1) I successfully deleted all ABS codes by unplugging the battery. I am now driving around with my ABS code reader and every time I stop, I am checking for codes. I've driven to about 3 or 4 places, and have generated NO codes. Of course, the weather is much better here now, so I wouldn't be surprised that some of my codes were just from having snow and crap get shoved up into the wheel wells, etc. Only people who are used to driving in snow will understand what I mean here I think - it just can't be avoided sometimes. But time will tell. Especially if I stop once, and all 4 wheel sensors go bad!!!!
Yes I do have ABS, it has engaged like it should. (when the ABS indicator light is not lit of course) Sometimes it engaged just doing a routine stop, probably indicative of wheel sensor issues. (but not now that I have erased everything)

2) I am now leaving traction control working normally just to see what happens.

I will keep this thread updated for those interested,

-Jerry

Couldnt help but read this, I just had this start to happen to me with The ABS light comming on and then going out . I have found out that when it does come on for me i shut the vehicle off then start it back up right away..it goes off. I thought since i was due for brakes all around (front and back) this might be why. I decided to go to my local shop as i needed alot of work to pass my inspection so i had them replace drums, rotors, pads, shoes, wheel cylinders, brake lines, and tie rods on both ends....i return to pick my vehicle up as soon as i start it the ABS light comes on! I shut the van off and restart it went off...my mechanic tells me he cannot pull the code off if any when the light is off. I also live in BUFFALO....and yes i had alot of wet snow and ice and crap up in the wheels as well. If anyone can make any corrolation to the wet weather for sure that would be great.

... the nightmare lives on, and on, and on ...
.
http://www.automotiveforums.com/vbulletin/showthread.php?t=938570

Erikx, this may be an oversimplification of your problem, but these darn Windstars and their ABS and Brake warning lights are excessively sensitive (the float sensor in the brake fluid reservoir) to the slightest bit of drop below the MAX line. It may have originally come on because your brake pad and shoe wear were enough to lower the fluid level low enough to turn on the lights, or you had a leak. Since all of that is new except your calipers, abs pump, metal lines, and reservoir, you could just again have a smidge too little in the reservoir. One mine, I've found a hard brake or hard cornering will trip it when the level isn't quite low enough to turn the lights on all the time. Topping it off is fun as there is no head room with the cowl in the way. So, with a full bottle, a clever way to pour it in without spilling is to position the bottle mouth with its lid on over the reservoir opening and then open it till a little over max, then cap bottle while in place if necessary.

BTW, you don't have the infamous leaky brake pressure switch, which is screwed into the bottom of the master cylinder? They are prone to leak and cause LOTS of problems and will mess up the trans switch if it gets too wet from fluid dripping on it.

Yeah that quite possibly be it...also i took it back to the shop with the light on actually and they ran a diagnostic and the code came up with the LF sensor. He cleaned off the sensor that had a crapload of snow built up in the well and some lefdt over brake fluid and cleared the code hasnt come back on all day....so far. Now that brake deactivation switch i just looked at...there is some fluid just sitting in the rim on top of the sensor but no fluid is in the wires as of yet and are dry....so it looks like im going to replace that myself just in case...lol.

And just thought of this now....what if the master cylinder was overfilled??? same effects? as just by looking it may be so

To be honest with you....if it is the original switch.....for the price of the switch (no more than $20), I would replace it.

Several folks have reported it starting a fire.....and that is not something any of us want to see happen.

It appears light will still be on and off all the time now...but yes i am replacing the switch in the morning to see if that solves it....and it also said the sensor wasnt actually bad per se the tech said it appears to be missing! as in the magnet not picking up the signal sometimes....so all in all if the switch doesnt fix it i will replace the sensor in the wheel for about 40 bucks and go from there...i will keep ya posted as i make progress.


edit: ok i think i want to replace the abs sensor at the left front wheel anyways...does anyone here have pics of or know what is involved on a job like this? does appear all that difficult but would like some guidance if anyone knows for sure.

It appears light will still be on and off all the time now...but yes i am replacing the switch in the morning to see if that solves it....and it also said the sensor wasnt actually bad per se the tech said it appears to be missing! as in the magnet not picking up the signal sometimes....so all in all if the switch doesnt fix it i will replace the sensor in the wheel for about 40 bucks and go from there...i will keep ya posted as i make progress.


edit: ok i think i want to replace the abs sensor at the left front wheel anyways...does anyone here have pics of or know what is involved on a job like this? does appear all that difficult but would like some guidance if anyone knows for sure.

From what I recall, it is very simple and straight forward as it appears. There are one or two fasteners that hold the sensor at the axle, a fancy nylon clamp on the strut tube, and the actual electrical connector. Possibly one more wire holder. The most important thing is to carefully release the tabs on the clamp and the connector so they don't break but enough so that you don't pull the connectors and wiring apart when they don't seem to be releasing. That would be bad but fixable. Hopefully the replacement sensor wiring connector will come pre-lubed with electrical grease, but if not, you want to put some di-electric grease on it to avoid future problems.

Yeah that quite possibly be it...also i took it back to the shop with the light on actually and they ran a diagnostic and the code came up with the LF sensor. He cleaned off the sensor that had a crapload of snow built up in the well and some lefdt over brake fluid and cleared the code hasnt come back on all day....so far. Now that brake deactivation switch i just looked at...there is some fluid just sitting in the rim on top of the sensor but no fluid is in the wires as of yet and are dry....so it looks like im going to replace that myself just in case...lol.

And just thought of this now....what if the master cylinder was overfilled??? same effects? as just by looking it may be so

That fluid on the rim of the brake pressure sensor could be just from the brake work, refilling it, etc. When I have a spill there, I will spray it down with brake cleaner just to be sure it doesn't cause any problems with the electrical stuff, especially with it dripping on the trans switch. I don't know what years have that problem. I suppose a search would reveal that, but I wasn't willing to read more than the sticky on the Windstar home page.

Overfilling the master cylinder will cause the brakes to not be able to release if the fluid gets hot enough causing them to drag. Eventually the fluid will get hotter and hotter from the brakes getting hotter and hotter from the brakes dragging causing the fluid to expand. But there is no room for it in the overfilled master cylinder, so the pressure in it just will continue to spiral upward in a vicious cycle until the brakes lock or the master cylinder cap blows off or a weak brake line gives, etc. The expanding fluid is also why the fill cap has that rubber accordion boot inside it. I could be wrong, but I'm not aware of a high fluid pressure sensor for the brakes, but maybe the low pressure sensor is also checked by the ABS system for too high pressure too.