Speed sensors

[Oprah]

So according to the dealership I need to replace the driver front and passenger rear speed sensors. I am on 33's. In theory, the stock speed sensors will send a signal thats too slow to ECU/ABS/etc... due to larger tires (dunno where the speedo fits in, I'm thinking after the ECU). Dakota digital doesn't recommend using their unit to send signal to ABS. So all in all to me this says that the signal to my ABS won't be correct unless I run stock size tires. In theory what this means is that my traction control won't function ideally with 33's.

Maybe that doesn't seem like a big deal, but I then think about modern Land Rovers, and how impressive their capabilities are. In theory A LOT of their capability is drawn from their incredible traction control system (from what I can tell, they also do have many more sensors other than just speed sensors such as suspension down/up travel sensor, etc., and more robust computing ability I'm sure).

So this leads me to think about swapping speed sensors. My capability is definitely hindered while having the speed sensors on the fritz, and also didn't seem to work as well with 33's vs. stock tires (before speed senors crapped out). What if I swapped to sensors that are designed for use with 33's, maybe from a tundra? did any toyota come with 33's stock? or is there any other aftermarket sensors that could do this? has anyone ever done something like this? am i correct about the dakota digital issue of not sending signal to abs unit?

I not in a huge rush to fix this, this is more curiosity on the subject right now.

Let me know what you guys think!

 

[D Farms]

the traction control works fine with oversized tires, my stock size was 225/75r15 and im running 315/75r16 now. also you cant just change speed sensors you would need to have abs tone rings specifically for your tire size, which would probably need to be done by a machinist at a machine shop.

another option is to use 4 of the dakota speed sensor boxes, one for each sensor, this would keep your abs and traction control within stock spec.

this is a picture of the tone ring and the sensor. basically if you go up in wheel size your ring needs more teeth.

 

[Oprah]

So maybe in theory new tone rings could be bought and run with stock speed sensors? I know the traction control will work with stock tone ring and sensor even with larger tires, just one of those thoughts, "could it be better?", ya know? :tongue:

Also, sounds like you know some about the Dakota set ups; at what point in the system would a single unit get installed to fix just the speedo and odo?

 

[D Farms]

I dont know of a place where they can simply be bought, they would need to be custom made at a machine shop.

theoretically if you did get 4 dakota speed modules you may be able to splice them in directly into the sensor line. I dont know how well this will work, and it would be 4 times as expensive.

this is uncharted territory, but I believe having some custom abs tone rings made would be ideal.

 

[98OzarksRunner]

I doubt that the tire size difference would have any appreciable effect on the traction control, ABS, or VSC. Those systems measure speed differences between the tires (e.g. if one wheel is spinning faster than the others it detects that as loss of traction). As long as you have the same sized tires on all 4 corners it should work as designed. From the FSM, it looks like the system does use vehicle speed to enable some condition checks (e.g. 'enable this check if over 19 mph'), but going from 30" to 33" tires shouldn't bother it much (9% difference in actual speed - instead of the check threshold being 19 mph it's now 21 mph).

I'm on 32" and I know mine works. The TRAC tries to kill me by pulling throttle when I'm trying to cross a busy intersection in the snow, the VSC beeps at me every time I try to take a curve at what I consider a reasonable speed, and the ABS has saved my butt a couple of times on icy backroads when I was going a little too fast. I do like being able to turn off TRAC and VSC (Andy Mod 2.0).

 

[Doc2012]

Another option.... and easier..... From my mod thread. If the pics don't work, let me know.

Here's another write up for you guys.

This is the Speedo Mod.

Basically, what Toyota did, and don't ask me why, was to run the speedo sensor through the ABS. How it works, I really don't know, but I do know it has something to do with the pulses of the ABS ring. And that's all I care to know, honestly.

When I did my Manual Hub Swap, and my 8.4" in the back, I completely lost my ABS, so there went my speedo. Drove around for a while with no speedo, using an app on my iPhone, and the RPMs of the truck to gauge how fast I was going.

Finally, I found the parts I needed from a guy who was willing to them off of a wrecked Taco.

When I did this mod the first time, I didn't realize what a half-assed job I did, until I got under the truck today to replace my wiring harness. (Special thanks to [MENTION=78895]DeathCougar[/MENTION] for having the right harness, and his timely delivery of it!) Hopefully that will fix my CEL that I've been having a problem getting rid of. :shrug:

Here we go:

Parts needed:

Speedo sensor out of a Tacoma. Any year will do. If you're running different gears like I am, then you don't really need to worry if the gear is right. My speedo is 16% off because of the 4.88s that I'm running. If you're running stock gears, see if you can get one from a Taco with your gearing. That should keep your speedo pretty damn accurate.

18ga Wire, a lot of it. You can use one color, or you can use three seprate colors. The choice is yours.

Wire cutters/strippers. :girl:

Butt-Connectors or Soldering Iron and solder.

Shrink Wrap- again, lots of it.

Now, first thing you want to do is to take your gauge cluster out. If you don't know how to do that, then I'm sorry. I didn't take Pics of taking all the crap off.

Once your Gauge cluster is out, you'll have your plugs resting on the steering wheel. You can see here how I already had this done, just a craptastic job, so I re-did it.

The wires you're going to need from the gauge cluster are going to be on the small blue connector, and the brown connector. They are the Blue and Grey wire on the Blue Connector, and the Black and Yellow Wire on the Brown connector. These need to be cut so you can splice your Speedo Sensor into them.

On your speedo sensor, there should be a Green wire with a Red stripe, a Blue wire, and a Pink wire. On mine, the Pink wire is the Position One wire, the Blue wire is the Position Two wire, and the Green w/ Red stripe is the Position Three Wire.

These wires are going to be extended, and then spliced into the gauge cluster.

The Position One wire(Pink, in my case), goes into the Black and yellow wire.

The Position Two wire(Blue) goes into a blank space in the Blue connector.

The Position Three wire(Green w/ Red Stripe) goes into the Grey wire with a Blue stripe.

I used some "weather Proof" butt connectors from the speedo sensor to my extension wire. These things are pretty nifty. They're basically butt connectors, that are convered in shrink wrap, with a glue in them to seal the wires off.

A closer shot of the glue in there.

Then, to keep the wires all together, I shrink wrapped them all together. This was a PITA. I basically had to cut a section of shrink wrap about 18-24" long, and feed the wires through it one by one. Now, I had only one color wire at the house, and really didn't feel like going to the store to get more, so I just tied knots on the end of them, to remember which one was where. One knot for the Green w/red, two knots for the blue, and three for the pink. Here's a Pic:

The shrink wrap wouldn't go over all three butt connectors, but, like I said, they're weather proof, so I'm not too worried about it.

The Speedo sensor needs to go on the transfer case, at the back. ON the 4Runner, there is a plug where it needs to go. A Pic for reference. That one bolt is all that holds it onto the t-case.

I plugged mine in, and ran the wires over the transmission along the wiring harness to keep them out of the way. Then I ran them into the grommet where the body ECU somes out at the fire wall. Then up behing the dash, just by feeding them up, and pulled them through where the gauge cluster sits.

Now, remember how I said the Blue wire needs to get put into an empty slot in the blue connector? Yeah. It's this one. It's right next to a solid green wire. You can also see the grey wire with a blue stripe that I cut.

Now, all that's left, is to splice the wires together. I took my extension wires, and twisted them to the wires that were NOT on the connector. Then, I put a normal butt connector on them, and crimped it down.

For the Blue wire in the empty space, I just stripped it, fed it through the slot, and bent the wires up so they wouldn't fall out.

Here's a Pic of all the wires connected. You can see what I did with the butt connectors.

After that, All you have to do is plug it in, and you're all set.

Keep in mind, that if you're running aftermarket gears, you're speedo is gonna be off. If you didn't get a speed sensor from a Taco with your same gear ratio, your speedo is gonna be off.

Buy this, and it'll take care of that. I'm about to buy one so I can adjust my speedo.

Universal Speedometer Signal Interface

That's all there is to it, guys. Any Questions, feel free to ask.

 

[Oprah]

Another option.... and easier..... From my mod thread. If the pics don't work, let me know.

So this is basically grabbing the speed from the transfer case instead of the speed sensors?

 

[Doc2012]

Yeupp.

The 4Runner uses the ABS rings for the speed sensor, hence having to go through the ECU.

With this, you by-pass the ECU, run straight to the cluster.

If you get the SGI-5 from Dakota Digital, you can change your speedo depending on whatever gear/tire combo you want, without having to change the gear on the speed sensor.

 

[Oprah]

Ok, I see the point about the traction control working off of differences in speed. Thats a good point. But, does the traction control have a minimum speed to engage as well? If so it might not engage quick enough ya know?

The other thing I was thinking about is the transmission. Doesn't it use the speed reading to some extent to determine shift points?

Thanks to all you guys for info and conversation.

 

[Oprah]

Yeupp.

The 4Runner uses the ABS rings for the speed sensor, hence having to go through the ECU.

With this, you by-pass the ECU, run straight to the cluster.

If you get the SGI-5 from Dakota Digital, you can change your speedo depending on whatever gear/tire combo you want, without having to change the gear on the speed sensor.

That corrects the speedo, but doesn't correct the traction control at all though, ya?

 

[Doc2012]

I don't know.

I don't have traction control in my 4Runner.

I would assume there's a way to disable the traction control, if one was so inclined.

I know I got rid of my ABS, like pump, master cylinder, all that crap.

Maybe you can just pull a fuse if you want it to go away?