Scorpio ABS sensor substitution

Scorpio / Scorpio Cosworth Discussions - Questions, problem resolution, general talk, technical tips and modifications.
Post Reply
brokencase
Level 4
Level 4
Posts: 360
Joined: Sun Dec 06, 2015 12:18 pm
Location: PA

Scorpio ABS sensor substitution

Post by brokencase » Mon Apr 15, 2019 7:22 pm

Does anybody have a spare front ABS sensor for a Scorpio on the shelf that they can measure for me?

I need the diameter and height of the "cylindrical portion" that goes into the hub.

I think I may have found an inexpensive substitute.

Ed Lijewski
Level 8
Posts: 7123
Joined: Thu Sep 04, 2003 5:53 pm
Location: The Belly of The Beast

Re: Scorpio ABS sensor substitution

Post by Ed Lijewski » Tue Apr 16, 2019 9:04 am

D= 17.8mm
H= 24.4mm (including O-ring groove).

YMMV
Descartes: "Cogito Ergo Sum"
Lijewski: "Sum Ergo Drive-O. Mucho!

brokencase
Level 4
Level 4
Posts: 360
Joined: Sun Dec 06, 2015 12:18 pm
Location: PA

Re: Scorpio ABS sensor substitution

Post by brokencase » Tue Apr 16, 2019 8:43 pm

Bingo! I think we have a winner...

Image

The height of the cylinder is a little longer at 27mm. But a 3mm spacer can easily be made to take care of this.

Ed, check the center to center distance. (Center of center of cylinder to center of mounting hole)

Next step is to install on car with some sort of rigged connection to see how it performs.
The problem is I don't have anywhere slippery to test!

If all goes well, I can cut/splice the connector side. It would really be nice if I could find the mating connector to
the one on this sensor.

The unit cost under $10. But i won't say where it came from until I test it out first.

Ed Lijewski
Level 8
Posts: 7123
Joined: Thu Sep 04, 2003 5:53 pm
Location: The Belly of The Beast

Re: Scorpio ABS sensor substitution

Post by Ed Lijewski » Wed Apr 17, 2019 7:18 am

I measured the sensor dimensions on the spare set in my stash; can't get the other measurements for now.

YMMV
Descartes: "Cogito Ergo Sum"
Lijewski: "Sum Ergo Drive-O. Mucho!

brokencase
Level 4
Level 4
Posts: 360
Joined: Sun Dec 06, 2015 12:18 pm
Location: PA

Re: Scorpio ABS sensor substitution

Post by brokencase » Thu Apr 18, 2019 12:30 pm

No problem. I'm going to try a test fit on the car tommorrow. I am optimistic the mounting bolt hole will be "close enough".

I found the following regarding testing. This is from "Debuging the Milano ABS" (Teves)

"Check the speed wheel clearance using a brass feeler since the pickup is magnetic and set it to factory specs.
The fronts should be 0.7 mm and the rears 1.1 mm. You can check the AC behaviour of the sensor
by lifting a wheel and spinning it. You can use an oscilloscope or a multi-meter and you should see
a small AC voltage being generated. At 1 rev/second you should see an AC voltage of between
0.15-0.7V."

So I will set clearance and spin the wheel and check with the o-scope. This subsitute sensor has a 1500 ohm resistance and the manual says 800-1400 ohms for original sensors. But I don't believe that to be a problem. If you are familiar with magnetic pickups on guitars the higher resistance only means more windings. If anything it means these will put out a stronger signal.

The only question is what to do about the connector? I could chop the connector off of the old wheel sensor and splice it on to this sensor....or I could 3d print the mate to the connector on this sensor and adapt on the vehicle harness side...

The downsides.. No groove for o-ring. A smear of silicone will address that. These are also all plastic construction.

brokencase
Level 4
Level 4
Posts: 360
Joined: Sun Dec 06, 2015 12:18 pm
Location: PA

Re: Scorpio ABS sensor substitution

Post by brokencase » Fri Apr 19, 2019 6:30 pm

Did the test fit today.. If it were not for the connector I would say that this sensor is practically a "drop in".

The cylinder lengths are very close. I can mount the new sensor in the hole and spin the hub and I don't detect any interference.
However, I measure the length from the base of the cylinder to the tip of the pole to be about 27.8mm on the original Scorpio sensor.
The "new alternate' sensor measures about 0.4 mm longer at 28.2mm I think it works out nice to put a thin gasket around the base since there
is no O-ring seal on the new sensor.

As you can see in the pics below - the original mounting bolt is too short and a longer replacement will be needed. I will look for some
stainless metric cap head bolts. The mounting hole lines up just fine!

I hooked up my mini oscilloscope and spun the hub to see the expected AC waveform. However - notice the difference in the poles on the tip of the sensors. Hopefully this won't have too much impact.

The rubber strain reliefs that slide over the cable and "snap in" to the sheet metal brackets are identical. However they are in the wrong position on the cable. I was able to apply dish washing detergent and slide them to the proper locations. There is a "plug" to go through the body work hole that might fit the hole on the Scorpio. Otherwise the cable is longer than the Scorpio sensor's and this leaves plenty of room for splicing. I think I will cut the old connectors from my sensors and splice them onto the new sensors.

Image

Image

Image

Image

brokencase
Level 4
Level 4
Posts: 360
Joined: Sun Dec 06, 2015 12:18 pm
Location: PA

Re: Scorpio ABS sensor substitution

Post by brokencase » Fri Apr 19, 2019 9:59 pm

The alternative sensor under investigation is from a 2000-2006 Ford Transit.

I bought three from Banggood.com and I think they are now out of them
https://www.banggood.com/ABS-Wheel-Spee ... rehouse=CN

You can also get them from here...
https://www.aliexpress.com/item/Wheel-S ... 56732.html

...or here...
https://www.lifeitnow.com/product/abs-w ... gJXU_D_BwE

You can probably find them elsewhere. But probably not from a USA vendor because they did not import the Transit to US until 2010 or so.

Be advised I have not yet proven these out and the normal "at your own risk" exclusions apply...

User avatar
Bob Weir
Membership Coordinator
Posts: 926
Joined: Tue Oct 14, 2003 6:49 pm
Location: Allentown PA

Re: Scorpio ABS sensor substitution

Post by Bob Weir » Sat Jun 15, 2019 10:04 am

FYI It's my understanding, the wires [ABS to wheel] are wheel specific, but that may only be due to different lengths.

brokencase
Level 4
Level 4
Posts: 360
Joined: Sun Dec 06, 2015 12:18 pm
Location: PA

Re: Scorpio ABS sensor substitution

Post by brokencase » Sat Jun 15, 2019 2:15 pm

What do you mean Bob? Connectors to these sensors are different. They need to be adapted. I bought some weather sealed two teminal connectors from ebay that I think i will use. Like these

https://tinyurl.com/y2fm5f2c

These units appear to be much longer than the Scorpio's and can be cut to length.

Still haven't gotten around to trying them out yet.

User avatar
Bob Weir
Membership Coordinator
Posts: 926
Joined: Tue Oct 14, 2003 6:49 pm
Location: Allentown PA

Re: Scorpio ABS sensor substitution

Post by Bob Weir » Sat Jun 15, 2019 11:14 pm

If I remember correctly, when I removed them from a donor, all 4 cables were of different length. From shortest to longest: Left/front, right/front, left/rear, right/rear. Jeff Herson & Jan Talian should know for certain.

Post Reply