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ABS Wheel Speed Sensor (TT vs NA)

20K views 22 replies 9 participants last post by  GMonster 
#1 ·
I just picked up a Haltech Elite ECU and got my Supra up and running on it last night. One of the big reasons that I switch was to use the traction control feature.

I started looking into wiring last night and found this article.

http://mkiv.com/techarticles/racelogic_Install/index.html

Specifically this picture:



My car was originally an NA...all I need is the ability to grab one of the front wheel speed sensors and I'm good.

Is the above pic the same for both TT / NA models?

Can I just splice into pin 4 on A20 and be done?


Thanks
 
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#2 ·
If I remember correctly when I wired my ProEFI traction control up, they are not in the same locations as the TT... Just look up the NA ABS sensor locations for your chassis (online manuals) and you should be able to find them pretty easily... Let me know if you can't and I will dig them up... Text me if you need ;)
 
#4 · (Edited)
Okay guys I will do a little breakdown in hopes to help you out... This is just for information only as I have posted screenshots from the OEM wiring diagrams... Be sure to verify this as some years may differ... My car is a 1995 and it worked perfectly...

So the NA cars do not have traction control from the factory... The ecu is an ABS ecu only and here is the pinout that I used for my car... The pin numbers from NA to TT differ at the ABS ecu, with the exception of the rear left hand sensor... So please use this diagram if you are doing this on an NA chassis...



***NOTE:The diagram below is for TT cars with factory traction control/ABS...



As you all can see, the Front RH, Front LH, and Rear RH are in different pin locations than the NA ABS ecu...

You will need to use one of the front sensors and one of the rear to wire into the standalone... I do not believe it matters which one, as long as you have a Limited Slip Differential and both rear wheels spin at the same rate...

I hope this helps!
 
#6 ·
Milton, I know it’s been more than a decade since this post, but we’re did you find this wiring diagram? I have 93.5 na abs ecu and none of my colors match you wiring diagram. I was hoping there’s one for my year.
 
#7 ·
Here's a little more information ...
While you can pick up the wheel speed signals right from the sensors as they go into the ABS/Trac ecu, as below
260834

That would be Connector A20(A) pins A17(front right) and A5(front left) and A21(B) pins B2(rear right) and B9(rear left). This is a pain - hacking into two connectors carrying fragile signals. Those sensor signals are very analog, and can be noisy ...

But there is a better way - way more robust to pick them up where the ABS/Trac ECU sends the signals on to the Traction ECU, all nicely cleaned up and square-wave. These are all on connector T9(A), and the Traction ECU is right next to the main engine ECU, making connections short and simple.
260835


Look to T9(A) pins A20(front right), A6(front left), A19(rear right), A7(rear left). The ABS/Trac ECU does the work for you, cleaning those wheel-speed signals up and presenting them as nice square-waves to the Traction ECU.

If you're going standalone you would likely be removing the Traction ECU anyway, so that T9 connector is right there ... Even better, to avoid cutting up the harness or anything, you can grab this PCB Miata connector from BMotorsports. One of the larger male connector sockets on it matches the T9 connector.
260836
260837


Cut the connector off (the center connector is sacrificial), trim the pins, solder your standalone ECU wires to those pins. Now it will plug right into the T9 connector on the harness. Simple. Clean.

Of course, this all is predicated on you having a car with the ABS/Trac ECU and the Traction ECU. And that you keep ABS in the car (always a good thing I think) so the ABS/Trac ECU can do the signal processing.
 
#8 ·
Here's a little more information ...
While you can pick up the wheel speed signals right from the sensors as they go into the ABS/Trac ecu, as below
View attachment 260834
That would be Connector A20(A) pins A17(front right) and A5(front left) and A21(B) pins B2(rear right) and B9(rear left). This is a pain - hacking into two connectors carrying fragile signals. Those sensor signals are very analog, and can be noisy ...

But there is a better way - way more robust to pick them up where the ABS/Trac ECU sends the signals on to the Traction ECU, all nicely cleaned up and square-wave. These are all on connector T9(A), and the Traction ECU is right next to the main engine ECU, making connections short and simple.
View attachment 260835

Look to T9(A) pins A20(front right), A6(front left), A19(rear right), A7(rear left). The ABS/Trac ECU does the work for you, cleaning those wheel-speed signals up and presenting them as nice square-waves to the Traction ECU.

If you're going standalone you would likely be removing the Traction ECU anyway, so that T9 connector is right there ... Even better, to avoid cutting up the harness or anything, you can grab this PCB Miata connector from BMotorsports. One of the larger male connector sockets on it matches the T9 connector.
View attachment 260836 View attachment 260837

Cut the connector off (the center connector is sacrificial), trim the pins, solder your standalone ECU wires to those pins. Now it will plug right into the T9 connector on the harness. Simple. Clean.

Of course, this all is predicated on you having a car with the ABS/Trac ECU and the Traction ECU. And that you keep ABS in the car (always a good thing I think) so the ABS/Trac ECU can do the signal processing.
Where are you finding those wiring diagrams? I have poured over various links from other forums with pinouts for the ABS ECU for JSPEC, 97+, USDM, etc. and have not come across the Traction control ECU pinout anywhere.

I would love a pinout of the 93 J Spec Traction control ECU. Even better (spoon feeding) would be the pinout calling out the wheel speed sensor signals at the traction control ECU.

I instead used the ABS ecu wiring under the centre area of the dash behind the radio as per the racelogic traction control wiring instructions. I would much prefer to use the factory traction control ECU wiring for the ABS wheel speed signals but could not find the pinout anywhere for a 93 j spec.
 
#9 ·
I have a pdf of the J-spec wiring diagram manual
261052


Shoot me an email address. It's 31meg in size. I don't see any mention of Traction control in there though ... Did the early J-spec Supras not have Traction control ?

I take it back. There's this (not much)
261053


So it looks like Traction control only came in after 97.8 ...
 
#12 ·
My 93 Jspec has ABS and traction control. I have the traction control ECU removed. The wiring harness for it appears to have many more pins than the USDM version. I have access to the Jspec translated wiring diagrams and have been perusing forums for the traction control ecu pinout but have yet to find it - that's all I am really looking for. Let me know if you happen to come across it.

E.g. : Exclusive! JDM Wiring Diagrams

I will post here the ABS ECU pinouts for anyone else that searches this thread for wheel speed sensor info for traction control. I made a doc for myself with this info:



Wire colours
ABS wire Colour RLTC wire colour Wheel
--------------------------------------------
A21-3 RED RED FR
A21-8 WHITE YELLOW FL
A20-10 BLUE BLUE RR
A20-22 PURPLE GREEN RL

Another reference confirming wire colours

Same for both J and UK spec.
RaceLogic Trac control wiring 1996+

Small Plug
Pin 3 Red wire .......Front Right Wheel
Pin 8 White wire......Front Left Wheel

Large Plug
Pin 10 Blue Wire......Rear Right Wheel
Pin 22 Purple Wire....Rear Left Wheel
 
#11 ·
I have an Elite 2500. Based on comments here and elsewhere, it really looks like a top-end system. Here's a copy of the wiring map I'll be using for my install


The aim was to NOT hack up the stock harness. C16 Cruise control needs to be de-pinned and re-pinned into another connector since you can't get the male mating plug. But male connectors for just about everything else are available.
 
#13 ·
HI... I just bumped in to your site, while exploring the pin connections of the ABS/SKID ECU of my RAV4 - ACA21, AWD.
The ABS lamp comes on at 60 KMh. and remains on until ignition is off . This has been happening since I had the car ( about 6 months). Tried all sorts of scanners and a long list of codes come up all which translate towards the power to actuator relay.. No tracing can be done since all the sockets are sealed at the actuator. In desperation I thought of cutting the wire to the lamp so that I can remain cool while driving.. There is no snow here and max speed is about 60-unless you hit a motorway.
The part number is 89540-42110 for the SKID ECU and 44510-42020 for actuator.
If you can direct me towards the pin configuration - I would be much obliged..

Cheers...
 
#17 ·
I'm an idiot. The JDM Electrical manual doesn't list Traction Control as TRAC it's listed as TRC. Here are the relevant pages for both pre-96.4 and after 96.4
View attachment 263929

View attachment 263930

View attachment 263931

View attachment 263932
This is fantastic, thank you! I am at work but will scan through the pre-96 diagram and find the pins with the wheel speed signals. Looks like the connector and pin #s are there.

That explains why I couldn't find the TRAC pinout when searching for "TRAC" and "traction" and the like in the JDM wiring diagram PDF.
 
#19 ·
263944

263945


Am I reading the wiring diagram correctly for the Pre 96 Halfwalker?

Pins
11 RL
12 RR
13 FL
14 FR

On the Gray B42 TRAC ECU connector are the wheel speed signal wires from the ABS computer? I am new to reading wiring diagrams like this.

I'm not sure what kind of signal those are, and if they'd work for the raceTCS or racelogic traction control.
 
#20 ·
View attachment 263944
View attachment 263945

Am I reading the wiring diagram correctly for the Pre 96 Halfwalker?

Pins
11 RL
12 RR
13 FL
14 FR

On the Gray B42 TRAC ECU connector are the wheel speed signal wires from the ABS computer? I am new to reading wiring diagrams like this.

I'm not sure what kind of signal those are, and if they'd work for the raceTCS or racelogic traction control.
^^^Would like to know this too but for Haltech 2500. ^^^
 
#21 ·
Yup - the ABS ecu should be spitting out 0-5V signals on pins J11 (FR), I21 (FL), I7 (RR), J2 (RL). Those go INTO the Throttle Control ecu on pins O14 (FR), O13 (FL), O12 (RR) and O11 (RL).

Most aftermarket ecus can read pretty much any signal. For the Elite 2500, add a wheel speed sensor, assign it to an SPI input. Then create a number gauge in the ESP software for that signal, and spin the wheel. You should see the number change depending on wheel speed.
263950


Heh, NOTE: This isn't live in my car yet. I just have ESP up and running in a VM for now while a dink around with it, learning. Still waiting on parts ... Still waiting on FSR Street Fighter kit. Still waiting on Radium fuel bits. Still waiting on bits from PHR. Still waiting on bits from ToyotaPartsDeal.

<sigh>
 
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