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The mkiv Supra Owners Club

ABS wheel speed sensors


ttsupra97

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Hi all,

 

Hopefully, someone is up who can help me out.  My abs connectors don't match the jap-spec info supplied by racelogic.  i have a 97 jap spec which i believe matches the us spec connectos (a 12 connector socket + a 26 connector socket).  does anyone know which lines to tap?  from looking at my 97 us repair manual i looks like the pulsing lines A20-6, A20-7, A20-19 and A20-29, but i need to confirm this with someone first!!

 

Thanks!

Tony.

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I do not have the info on the 97 but if those are the ABS signal wires, it does not matter if you match FL to FL or any other pair with the RL unit as the system will learn what connections you have when you take the car for the configuration drive.

 

If as I presume you have identified these by a process of elimination, just splice any one to any of the  four RL wires and you are done.

 

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Guest Martin F

 

I remember being caught out at this point as well.

 

For some reason the position on the plug shown by the ABS diagrams from MKIV.com, does not marry up with the real position on a Jap spec car. But what does match is the colour of the wires.

 

So look for the correct colour wires, and yes there is two on each plug and the gauge of the four ABS sensor wires tends to be slightly bigger than the other wires.

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Looks like I'll have to have another go next weekend :(  trying ti splice those abs wires was so tedious i felt physically ill afterwards.  i currently have a white, red, blue and green wire sliced off the abs plugs, but when i attempt to calibrate the car (but shutting down, then plugging that plug onto the end of the diagnostic lead, then selecting one of the wheelspeed sensors, then starting back up, then taking the long lefthand turn), the car starts misfiring and never starts flashing in synch with rpm.  it's worth noting that the car runs fine with the unit in the off position, and the diagnostic led flashes in sync with rpm.

 

Anyone have any suggestions?  it's probable my abs wiring i guess...

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This sounds familiar, I seem to remember JB having problems like this. If I recall correctly the wiring was OK, it was the dat file in the RL unit, I think his was set up as a four cylinder car, so had a major  misfire. Martin or John may be able to help you here.

 

If you have a lap top I can send you a dat file that works, but you may have to change wheel sizes and do a calibration run.

 

Have you tried the switch in four positions, and got no rpm signal on any channel?  

 

You can jack up each wheel and get some one to spin it for you while you turn the selector switch to 20% 15% 10% & 5%. You should get pulses from each wheel.  This should tell you if you have wired one incorrectly.

 

If the dat file is shot your minimum speed setting may be too high. There are too many variables at the moment so I really can't give you an answer.

 

If you send me  the standard  dat file from your disc, I can check it for you, but that still not tell you what is in the TC control unit.

 

If you e-mail Graham Rudd he may send you his app for RLTC which makes set up and spotting dat file errors much easier.   However I know he is very busy at the moment. I you can get hold of his app you could send  me the dat file from inside you TC uint and I can check it for you.

 

 

(Edited by Phil Wall at 4:19 pm on Feb. 10, 2002)

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Guest Martin F

 

Hmm as far as i remember John didn't have any major mis-fire until the unit detected slip and then the cut was very severe, due to the config.

 

But from what Tony is telling us it would seem to start mis-firing as soon as the unit is calibrated, is this correct Tony ?

 

Worth noting that i have never seen the diag light start to flash in time with the RPM until after the calibration is completed, i think the instructions are contrary to this.

 

You really need to hook up a laptop and look at the data coming back from the ABS sensors it will be immediately obvious if there is a problem.

 

 

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Yes, my problem is that the calibration never succeeds, when i have the unit in calibration mode.  no matter how many 180 degree left-hand turns i do, the light keeps blinking on and off once every second, and the car starts to miss in calibration mode.  I think it's a safe bet that I have at least one ABS wire tapped in incorrectly, but I like the idea of jacking the wheels up and looking at the LED.  I'll try that tonight.  Another idea that was presented to me, is to tap the ABS lines at the trac ECU.  I like that Idea a LOT more that tapping at the ABS ECU.  I think I'll move my wiring there anyway...

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A small point to note is that my car will not calibrate until the engine has warmed up a bit, when its on its cold start settings the RLTC unit wont recognise the RPM, once it has warmed up its fine.

 

We also calibrated my car without the 9pin plug thing on the end of the diag cable and it seemed to calibrate okay.

 

JB

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Only finished installing mine about a week and a half ago.  First time I started the engine after finishing the install, with the RL controller in the 'OFF' position, the diag LED flashed in time with rpm, as per the instructions.  (Also did this when set on 20% slip)  Flashed in time with wheelspeed when set to wet, dry, 10% and 20% BEFORE ever carrying out the calibration run.

 

Branners, how did you manage to get your unit into calibration mode without the use of the 9-pin plug as this contains a pattern of shorted out pins which puts the unit into this mode?

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Guest Martin F
Quote: from ttsupra97 on 5:09 am on Feb. 12, 2002[br]Guys,

 

When you were calibrating, would the RL start misfiring the car if you stepped on the throttle at all (even slightly, just a bit more than coasting)?

 

Cheers,

Tony.

 

NO

 

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Guest Martin F
Quote: from ttsupra97 on 5:13 am on Feb. 12, 2002[br]Oh, and also, should the DOS software to monitor wheelspeeds and rpm be able to do this before calibration succeeds??

 

Thanks!

Tony.

 

YES, think you need to double check your install Tony.

 

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Bingo!  I checked over my ABS wiring and sure enough 3 of my connections weren't connected properly (take about poor success rate!).  At least I got the right wires.  So, now I can confirm that the 1997 US and jap-spec Supras have the same wiring where the ABS sensors are concerned, namely:

 

FR+ A21-3 (red)

FL+ A21-8 (white)

RR+ A20-10 (blue)

RL+ A20-22 (purple)

 

Cheers,

Tony.

 

(Edited by ttsupra97 at 8:54 pm on Feb. 13, 2002)

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Ok, well first off I tried those crimping clips you can get, but they weren't really for that gauge of wire, so 3 out of 4 clips hadn't even stripped the wire at all.  Then I decided to solder, but cut too much of one of the wires with my sidecutters before I got change to solder (I'm not stranger at all to a soldering iron or sidecutters, but I just couldn't feel comfortable poking around in a contorted position with a loom that had little to no slack at all), so I simply snipped the wires (last resort, didn't really want to do that, but hey) and reconnected with little devices called Posi-Locks which hold damn well (have been using them in an arcade machine I built at home for years and they have proven themselves).

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Guest Martin F

 

As i suspected...

 

Tip 1 - Never ever use Scotchlok (crimping clips) connectors they are just so hit and miss. They seem to end up being responsible for 9 out of 10 intermittant DIY installed alarms and stereo problems.

 

Tip 2 - I share your concern about tapping into that ABS loom, but rather than try to use side cutters to snip teh insulation back, try using the soldering iron to melt it back. Only problem with this method is you can't use heat shrink over the joint and have to rely on tape. :(

 

Glad you have it all working now, so tell us what are your first impressions ?

 

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Thanks Martin, I never actually thought of using the iron to melt the insulation off, even though I'd done it in the past occassionally by accident! :p

 

My impressions of the unit are very positive.  I love being able to punch the throttle around a corner knowing that I'm not going to lose it.  Of course, I know physics still plays a role here and I'm very mindful of the fact that Racelogic weren't able to change any of Newtons laws, but they've come close!

 

My unit came with a bunch of default values (4 cylinder, no specified soft/hard etc cuts, 40 pulses per wheel sensor), so I haven't really tried doing anything silly with the higher slip values.  Apparently, there has been a lot of research conducted here on how to tweak the TC for the Supra.  Phil said he'll be sending me a dat file soon with optimum settings for my stock sized wheels/tyres, so I'm expecting things to be amazing after I get to feed that into the unit.

 

I'm going to be trying to convince as many fellow Aussie owners to get one of these units in their cars, as the Supra is seriously underrated down here (everyone seems to put down anything that isn't AWD, and seem particularly frightened of high powered RWD), so the sooner we gets these RLTC's in aussie supras, the sooner we'll be able to show everyone what kind of potential these cars really have.

 

Cheers,

Tony

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Monkeymark,

 

Any competent auto electrician should be able to install the unit for you.  How comfident are you with working within cramped recesses of your car on looms of wire that have no slack in them at all?  It frustrated the hell out of me, but then again in hindsight, I'm glad I was the one that did it, because I learnt one or two more things about my car and have the piece of mind of knowing exactly what was done to my car.

 

Cheers,

Tony.

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