Alternate Rear ABS Sensors

9805 Views 34 Replies 13 Participants Last post by Alex W, 1 d ago

Alex W

Discussion Starter · Jan 3, 2021

2

I think I have identified a modern / readily available replacement for the rear ABS sensors.

2006-2011 Camry / Avalon front wheel speed sensors are basically the same design as the stock MR2 rear sensors, and with a little work fit the stock knuckle.

The diameter of the sensor is a little bit greater than the stock sensor, and the length is a little longer. However the length from the ridge by the flange on the new sensor to the tip is perfect. If you drill out the stock knuckle with an 11/16" drill bit the sensor fits and bottoms out on that ridge. The spacing to the bolt hole is slightly different, but close enough that a bolt will thread in. Shim it with a few washers or get fancy and make a spacer if you want.

The electrical connector is different, so you will need to splice on the old connector. You may be able to buy the correct pins for the old housing from someplace like Ballenger Motorsports - High Performance Electronics and crimp them on and install them into the stock connector if you really wanted to get fancy. The wires on the new sensor are a few inches longer than on the old.

Of course the various brackets and clips along the wire are different, but those can be swapped over from the old sensor.

Unfortunately I can't guarantee that it is electrically compatible with the stock ABS computer (I don't have ABS on my car to test with), but I think the odds are good. It LOOKS like the same style sensor, and the resistance of the new sensor is within the range specified in the BGB (.9 - 1.5 k ohm). For what it's worth my stock sensor measures about 1k ohm, and the new one measures about 1.5k ohm.

Best part is, you can get these all day long on Rock Auto for reasonable prices. Stock sensors are either unobtainable, or very expensive.

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JimKing

· #2 · Jan 3, 2021

Going the other direction (sort of), the Spyder ABS computer is happy with the MK2 ABS sensor's output. So there's another data point that indicates Toyota has kept the ABS sensor technology common across the years and models

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Abesdub

· #3 · Jan 6, 2021

Nice find for those that want to keep the ABS.
However from your experience would you say that the outdated 90s ABS on MR2s is more of a hindrance on this vehicle?
From what I’ve researched many owners prefer to disable delete the oem ABS and just install aftermarket brake proportioning valve and aftermarket brakes along with better suitable tires and suspension geometry parts to compensate to achieve better braking and handling compared to the slow old ABS electronic controls

Alex W

Discussion Starter · #4 · Jan 6, 2021

Abesdub said:
Nice find for those that want to keep the ABS.
However from your experience would you say that the outdated 90s ABS on MR2s is more of a hindrance on this vehicle?
From what I’ve researched many owners prefer to disable delete the oem ABS and just install aftermarket brake proportioning valve and aftermarket brakes along with better suitable tires and suspension geometry parts to compensate to achieve better braking and handling compared to the slow old ABS electronic controls

I don't have ABS on my current MR2, but sometimes I wish I did... Maybe I have forgotten how "not great" it was. I did have a 93+ ABS ECU retrofitted to my 91 system, which improved it quite a bit. There are various other retrofit options, the BMW system seems to be one of the better ones, but that's a pretty big project. People talk about using the Spyder system to get a more modern ABS, but I don't know that it's been done.

All of the other things you mention will improve the braking, handling, etc in various ways, but none of them really have anything to do with ABS, or anything to do with the decision to keep it or remove it.

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JimKing

· #5 · Jan 6, 2021

People talk about using the Spyder system to get a more modern ABS, but I don't know that it's been done.

Yes it's been done. I've been driving 2 different V6 MK2s with that mod for the past 8 years. It's a 4-channel system and much better than the 91 ABS. It's very nice to have for slalom / auto-x.

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Bandido

· #6 · Jan 6, 2021

JimKing said:
Yes it's been done. I've been driving 2 different V6 MK2s with that mod for the past 8 years. It's a 4-channel system and much better than the 91 ABS. It's very nice to have for slalom / auto-x.

Do you have any info on that conversion?
I've been looking to do something similar.

Alex W

Discussion Starter · #7 · Jan 7, 2021 (Edited)

I was thinking of asking the same thing. Looking into part costs a little bit, the pump and ECU are dirt cheap on ebay. Like under 100 bucks for the pump, and under 50 for the ECU. I imagine the wiring could be the most difficult part, but Spyders are new enough that wiring harness are common on ebay as well. A dash harness + a frunk harness should get you all of the connectors and wire you need, and they go for about 100 bucks each. So, unless I'm missing something it looks like one could do the conversion for around 400 bucks, give or take a bit, plus a bunch of time of course.

EDIT: I could be wrong, but it looks like the 2003+ version integrates the ECU into the pump. ToyoDIY says "Not Applicalbe" for the ECU on those years, and looking at the pictures of the pump, it seems to have a lot more pins on the connector than the earlier ones. That seems ideal, less wiring to worry about. Just need the pump and the frunk harness and you would be most of the way there.

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Bandido

· #8 · Jan 7, 2021

I did much the same, here's an EWD for 03-05, the key inputs are just the wheelspeed sensors and stp, which would make it electrically very easy to integrate...

The only thing that concerns me is seems to have an internal accelerometer, which may make it difficult to tune to achieve a proper racing ABS as is my target.

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Alex W

Discussion Starter · #9 · Jan 7, 2021

Bandido said:
I did much the same, here's an EWD for 03-05, the key inputs are just the wheelspeed sensors and stp, which would make it electrically very easy to integrate...

The only thing that concerns me is seems to have an internal accelerometer, which may make it difficult to tune to achieve a proper racing ABS as is my target.

Yeah, tuning it probably isn't going to happen. If you want to do that, look into the E46 M3 system.

Also, if you try to do this and go for the 03+ version, be careful about getting the right harness (assuming you go the route of buying a complete frunk harness for the connectors). There are several of the early style harnesses on ebay for around 100 bucks, they all SAY they fit 01-05, but the part number is wrong.

Bandido

· #10 · Jan 7, 2021

Great point, most junkyards will include a pigtail with a part pretty easily near me, I'll probably give this a try...
I should at least be able to get pretty good stopping distance and phone G info.

I was under the impression that the tuneable bosch ABS module for the BMW's was quite expensive still, but it sounds like I'll have to do some research.

Alex W

Discussion Starter · #11 · Jan 7, 2021

Quite a lot more expensive if I remember right. The Spyder system, while maybe not quite as awesome, certainly looks like a very affordable option.

JimKing

· #12 · Jan 7, 2021

IIRC, the info is on here in a thread I posted when I first did this some 8-10 years ago. I used an 00-02 Spyder ABS setup with separate ECU as it most closely matched the MK2 setup. The Spyder ECU is mounted in the stock location. This makes the most sense since the MK2 speed sensors are all routed to there. I made an adapter harness from the Spyder connectors cut from a dash harness and the sockets hacked out of a 91 MK2 ABS ECU.

I've also passed all the info on to Brad Bedell who is planning the same update for his yellow car. With my permission he is intending to put the wiring cross-reference in a public Google docs spreadsheet, but I don't know if that's happened.

Alex W

Discussion Starter · #13 · Jan 7, 2021

Makes sense. Personally if I were retrofitting this to a MKII that already had ABS, the 00-02 system does seem like a better fit. My car doesn't have ABS, so I will be running wires anyway, and with that in mind having it all integrated seems easier.

JimKing

· #14 · Jan 7, 2021

Some cars were built with wiring harnesses that contained the ABS wiring and connectors even if ABS was not installed as an option. There were two different SW22 frunk harness part numbers for 91-92 cars. One for stripper cars, and the other for cars with ABS or EHPS or Fog Lamps or Alarm. My first new MK2 was a stripper turbo - no options but A/C. It didn't have the ABS wiring, nor fog light wiring. The 93na I have now didn't come with ABS, but it was added later on by the 2nd owner (hard-core autocrosser), who installed components, but no wiring.

Best to check your car to be sure before assuming you have to run your own wires. Look in the frunk or the engine compartment for the taped up connectors. Toyota uses ~10mm wide white electrical tape to tape up unused connectors.

Actually, If the EPC is correct, then the only turbos w/o ABS wiring would be the early delivery cars "stripper" cars that didn't even have fog lights (like the one I had). *66 is Toyota-speak for ABS.

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Alex W

Discussion Starter · #15 · Jan 7, 2021

I don't remember if I have the connectors under the dash for the ABS ECU. I know my frunk harness does not (nor did it have power steering, I had to add that as a "separate" harness). Definitely no ABS connectors in the engine bay either (at least not any more). It's a 91 NA that had power windows and t-tops and not much else. I might have the dash harness from my old turbo, and I might have the portions of the funk harness that I would need to build an ABS harness, but that all seems like more trouble than just running sensor wires to one spot in the frunk.

Needless to say, my car is a bit of a hybrid of a whole bunch of stuff.

shiverdc2002

· #16 · Jan 7, 2021

Thanks for doing the research! I have a sensor that I recently had to repair (broken wire right near the sensor), so if that ends up breaking again, ill give this a shot. it also appears these are MUCH cheaper than the mr2 parts.

Alex W

Discussion Starter · #17 · Jan 7, 2021

shiverdc2002 said:
Thanks for doing the research! I have a sensor that I recently had to repair (broken wire right near the sensor), so if that ends up breaking again, ill give this a shot. it also appears these are MUCH cheaper than the mr2 parts.

You are welcome! Depending on how much you trust the quality on the really cheap ones, you can get these for less than 20 bucks... Seems a little sketchy at that point, but it's not a complicated sensor so they may well be fine. But even if you go with a decent brand they are much cheaper.

SixAppeal

· #18 · Jan 8, 2021

Here is a video of the difference abs can make on a car. Yes, it's a modern car with lots of electric aids vs a MR2 some guys built in a shed but you get the idea.

Alex W

Discussion Starter · #19 · Jan 8, 2021

SixAppeal said:
Here is a video of the difference abs can make on a car. Yes, it's a modern car with lots of electric aids vs a MR2 some guys built in a shed but you get the idea.

For sure. I'm not one of those guys who thinks he can out perform the ABS system! But my current chassis didn't have it, and while I kept all the parts from my 91T to add it back in, I never bothered until now. Just picked up a 2003 Spyder ABS module and frunk harness off of eBay.

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.Mr2Nice.

· #20 · Aug 16, 2021

I am very interested if anyone has confirmed this 100%, got a part number from rockauto? Thanks!

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