ABS weirdness

ABS weirdness

Postby Rockridge [OP] » September 19th 2020, 2:04am

Haven't driven the 01 AWD very much this summer. Did all new brakes last fall, calipers rotors, drums etc.

Today, when slowing I can feel that the rotors had some rust which I expected, so a little pulsing on the pedal and not smooth braking at first. Then when almost to a sop the ABS kicks in full force and I just about rear-ended a car. Continued like that to work at every stop (I planned ahead). Pumping the brake might have helped a little, hard to tell it's over so fast. Good braking until the last moment and then scary. I pulled the ABS fuse for the way home, no problems.

Am I looking at that ABS circuit board solder issue or does this sound more like a wheel sensor issue?

And yes, I spent a good 20 seconds searching the forum :). Sorry, no pics either.

Totally selling this van before winter.
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Firing on 8 Cylinders (L1)
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Re: ABS weirdness

Postby Wiley » September 19th 2020, 2:33am

Maybe you have air in your ABS unit, if it is that you want to find a dirt road and cruise around 30mph, and hit the brakes to get the air out.
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Re: ABS weirdness

Postby dchan51360 » September 19th 2020, 2:38am

My first inclination would be Most likely a bad wheel sensor.

https://testing-public.carmd.com/Tsb/Do ... 95/1748497

FYI there are times that the "cleaning" will not fix it and you will need to remove the speed sensor, clean the surfaces of rust, and replace the sensor with a new one. It has to do with the sensor failing or feeding incorrect data to the ABS module thinking that one of the wheels is loosing traction.

I had to have a hub replaced, and opted to get both replaced at the same time. The hubs come with new sensors so I was happy about that because I had not done these sensors on my current Safari. I did them on my Astro a couple times until I had to replace the hubs on that vehicle.
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Re: ABS weirdness

Postby dchan51360 » September 19th 2020, 3:17am

By the way, the specific symptom of this TSB is false activation of the ABS unit at low speeds. Specifically below 5mph.

On my first second van, it was bubbling and scaling under the mounting surface of the sensor causing an incorrect gap between the magnet and the sensor. I had to remove the sensor, dig out the cap of the sensor, grind off the scale and rust, to get it to seat correctly.

I gave that van up shortly after fixing this because the rust was getting to the point where I blew out a hard brake line while stopping. I decided I didn't want to replace all the brake lines just to keep the van going. Just too many other "rust" issues to consider it being safe any more.
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Re: ABS weirdness

Postby Leeann_93 » September 19th 2020, 5:09pm

dchan51360 wrote:My first inclination would be Most likely a bad wheel sensor.

https://testing-public.carmd.com/Tsb/Do ... 95/1748497

FYI there are times that the "cleaning" will not fix it and you will need to remove the speed sensor, clean the surfaces of rust, and replace the sensor with a new one. It has to do with the sensor failing or feeding incorrect data to the ABS module thinking that one of the wheels is loosing traction.

I had to have a hub replaced, and opted to get both replaced at the same time. The hubs come with new sensors so I was happy about that because I had not done these sensors on my current Safari. I did them on my Astro a couple times until I had to replace the hubs on that vehicle.



^ this. Was a problem on my '02 if anyone else drove it - and I never ended up replacing that hub (oops). What I found was, if you immediately lift your foot and apply the brakes again, it would brake normally. I never remembered to warn anyone else about that, though :doh:
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Re: ABS weirdness

Postby Rockridge [OP] » September 19th 2020, 10:41pm

That's exactly my scenario.

I found an easy fix... FOR SALE
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