It's not always the ABS module

Post by **Clemens** » 11 Jun 2021, 03:14

Even though we 96 upwards p80 owners know that the ABS/Tracs double orange means the module is faulty - it's not always the case, as I will photoproof here.

Interestingly, the lights were off in dry wearher and only came on in rauny condiruons, which made me suspect the wiring.

I guess a tiny rock got stuck in the ABS ring and slowly did grind off part of the sensor.

Post by **Clemens** » 12 Jun 2021, 14:09

But, the fantastic thing is: even though this should have been the issue, the double orange is back. I will measure the ohms between the pins of each single wheel sensor at the main connector one of these days

Post by **misha** » 12 Jun 2021, 15:50

I had abs sensor wiring problem this winter on driver's side front wheel.
It drove me nuts and the symptoms are almost just like bad solders in abs/tracs module except that it always triggered abs/tracs light on full right turn(it took a while before i discovered that).
Turn the car off(wheels are straightened),re-start...abs/tracs off as soon as i take off and i could drive whole day on freeway or anywhere before i make a full right lock(while parking or getting into a garage) and the lights come on again.

The wiring cracked inside the silicone insulation...no visible cracks on the outside and it looked like new on inspection.

Vol-Fcr was showing a code for intermittent fault and open or short circuit on left front wheel sensor(driver's side).
Sensor checked out ok...then i used a multimeter on module's connector for coresponding sensor and wiggled a wiring while watching values.
As soon as i wiggled a wiring where rubber grommet fits in a slot on a strut imitating a wheel turn...multimeter read open circuit and when i release the wiring to return to it's normal position...proper resistance showed again on multimeter.

Again...no visible damage on the outer silicone insulation and i decided to cut open that area carefully.
As soon as i removed outer insulation...one of the wires was broken.

24 years of moving the wheels from left to the right full lock broke one of the wires.

I repaired that section by crimping a little male and female crimp connectors on both ends on the section,insulated it with a heat shrink tube and insulating tape and few months later it's ok and abs/tracs module is happy.

If my repaired section fails....i will probably splice in the whole cable in the inner fender area.
As far as i could saw...it isn't a regular wire...it looks more like an o2 sensor wire and it seems like it is resistance sensitive.

Post by **Clemens** » 13 Jun 2021, 00:35

Thanks Misha, that is what I am suspecting, because sometimes it seems to be triggered by full lock steering qheel action, sometimes not. Really weird

Post by **hausmeister** » 13 Jun 2021, 11:14

Had to replace the rear abs wiring and sensor as well some years ago. (s70)
It helps If the car has obd2, with a reader you can check for wheel signals... at least I was able to do this.

Agree that blindly replacing or fixing abs module is not the way to go.

Post by **Clemens** » 13 Jun 2021, 12:48

hausmeister wrote: ↑13 Jun 2021, 11:14 Had to replace the rear abs wiring and sensor as well some years ago. (s70)
It helps If the car has obd2, with a reader you can check for wheel signals... at least I was able to do this.

Agree that blindly replacing or fixing abs module is not the way to go.

Well, good to know about the wore replacement. Since you are so close by maybe we should finally meet, it's been in the back of my head for a long time.

Post by **abscate** » 16 Jun 2021, 03:23

You guys should get together for a kangaroo BBQ.

I’ve never had any luck soldering those thin ABS wires in a way that lasted. In my maintenance record you will see I must have soldered them 4-5x. I finally realized the hours wasted were not worth the $50:cost of a new one

Post by **hausmeister** » 16 Jun 2021, 04:48

Clemens wrote: ↑13 Jun 2021, 12:48 Since you are so close by maybe we should finally meet, it's been in the back of my head for a long time.

I'm down with that. But don't expect much, my 850 has been through a lot and looks like it. Which is good as I don't need to worry about anything being pretty any more

Love those Kangaroo burgers

Post by **abscate** » 17 Jun 2021, 03:29

I have a business partner in Voralberg, and it used to crack him up at trade shows when I told people we were in Austria, land of kangaroos. Geography isn’t always a strong point in the US

Post by **Clemens** » 17 Jun 2021, 14:28

abscate wrote: ↑17 Jun 2021, 03:29 I have a business partner in Voralberg, and it used to crack him up at trade shows when I told people we were in Austria, land of kangaroos. Geography isn’t always a strong point in the US

Decades ago, I pulled up in a Burger King Drive through in Valley Springs, CA 95252, and the girl at the window asks me where I'm from. Said she could hear an accent, said I wasn't from the Valley (true). I replied "Austria". She said: Wow, I always wanted to go there. Is Crocodile Dundee like a national hero for you? I told her we have a monument for him in like every town. Then I took off with my 72 Continental...