3rd gen 4runner/ functioning speedo without wheels speed sensors

[Mossyrocks]

First Id like to say, this is at your own risk. And Im not sure of the outcome if wheel speed sensors are still in place.


You will need:
Output shaft speed sensor from a tacoma. J/Y or dealer ($220)
3 colors/ lengths of wire.
Butt splice connectors
Piggy back connectors.
If you dont have the tools, you shouldnt be doing this

Side Note:
If you go with a junkyard sensor as I did and youd like to check it. Connect the hot wire (as seen below) to the positive on the battery. Connect the ground wire (as seen below) to the negative on the battery. And with a volt meter attached to the signal wire, turn the plastic gear by hand. If you get pulsing voltage from the signal then its good to go.

At the output shaft on the pass side of the transfer case you will need to remove a plug. One 12mm bolt holds it in place.

Replace this plug with the tacoma output shaft speed sensor.



From the sensor harness there will be 3 wires. Black w/ red stripe (this is the hot wire. 12v) Solid blue (this is the negative) and Green w/ red stripe (the signal wire)



Extend the hot wire (bl-r) to a 12v source. I ran this straight to the battery with a 10a inline fuse.
UPDATE: Hot wire behind the dash is Black w/ a yellow stripe. Its on the brown connector.

Extend the negative (l) to a ground. I used the neg. on the battery.

Extend the singal wire (G-R) up behind the dash.

On the back of the speedometer there will be 3 connectors. Blue, White, and Brown. On the brown connector, second terminal is the input signal for the speedometer. This is the input from the ABS ECU. This wire is gray with a blue stripe. You will splice in the new singal wire with this wire using a piggy-back. I did not disconnect mine from the ABS ecu. It works without disconnecting so I figured Id leave it at that.



Then just put everything back together and your good to go.

If there is an easier way than please, let me know.

[OOP'S]

Extend the hot wire (bl-r) to a 12v source. I ran this straight to the battery with a 10a inline fuse.

Nice mod but don't you think the hot wire should go to a switched hot instead of being hot all the time?

[Mossyrocks]

it doesnt put anything out unless its turning. I wondered about that too though. I do have a hot wire for it located if it comes down to it. If it turns out it does, then Ill update.

[ErikB]

EXCELLENT tech! (maybe move it to the Taco section?)

I've been wondering about this exact thing since I'm swapping my old axles into my '97 and they don't have any ABS junk on them.

I'm using early (gear-driven) t-cases, so my plan is to do the same thing using Marlin's VSS ($59) on my old t-case. http://www.marlincrawler.com/htm/tra...e/tcase_ac.htm
You could probably have done something similar and saved some money on that sensor (use a cable drive + Marlin's sensor). The announcement thread of the VSS on Marlin's board talks about this.

I'll be using a switched hot too, but I doubt its a big deal. Just a small drain on the battery for the sensor, most likely.

Have you tried it out yet to see if it works?

If the speed reading is off, you "should" be able to correct it with one of these:
http://www.4x4wire.com/toyota/tech/tacoma_speedometer/
http://www.dakotadigital.com/index.c...rod/prd126.htm
(from this post: http://www.pirate4x4.com/forum/showp...2&postcount=14 )
I'm expecing it to be off since I'm mixing and matching so much stuff.

The other thing I wondered about is that I would think that the wheel sensors would send a lot more pulses per revolution than the t-case sensors (4 pulse?), so I didn't know if it would work. Maybe the ABS ECU converts the four wheel sensor pulses to a slower pulse the speedo and ECU understand.
Sounds like you've gotten it to work though.

[Mossyrocks]

Edited above for this. UPDATE: Hot wire behind the dash is Black w/ a yellow stripe. Its on the brown connector.


And to answer your question, 100 miles today, no check engine light, and the speed seems to be within 5. So 15mph off with wheel speed sensors and 37s. Almost dead on with output shaft sensor, 4.88s, and 37s.

I did all this for free. Picked up the taco sensor from a buddy, but I would bet that its only about 50 or less from a junkyard.

[ErikB]

I just realized I'm going to have to come up with a connector/harness for my sensor though.

[Dickfoster]

Even if the output isn't pulsing it will still draw current and eventually drag the battery charge down.
You can tell how much current it draws by either measuing it directly the ammeter function of your DMM. If it';s a simple passive sensor like a coil or something you can get a rough estimate by measuring the resistance between power in and ground, measure in both polarites in case there is a diode. The best way is to measure the current directly with the sensor hooked up to power.

[Mossyrocks]

I did some more measuring on the draw from the sensor. If you park it mid-pulse, Its gonna pull power so do what I did and connect the hot from the sensor to the black and yellow hot wire behind the dash. There are other positives everywhere but you might as well connect right next to the input signal wire since your already in there.

[cougarfreak]

Killer, no more gps speedo, WOOOHOOO!!!!

You rock Mossy!!!!

I'm going to see if I can hunt down an acc switched wire to tap into the hot... unless someone else has figured one out...

[cougarfreak]

I've got a source for the output sensor (TAP), but am wondering about the electrical plug that plugs into it. Is this something that my 4Runner has stock, or do I need that part from the wiring harness from the donor as well? They charge $75 for the sensor, and $45 to carve the plug outta the harness... Advice???

[ErikB]

Inchwormgear has boxes of used sensors from core t-cases and I bet they'd be cheaper. Marlin might too. I don't recommend TAP.

I walked around a pick n pull looking at all the different Toyota cars and was able to find plugs that matched and they didn't charge me for it (aside from the $2 to get in). Some of them were the same plug but with a different tab location (keyed left, middle, or right side tab). I grabbed a left and right tabbed plug and tossed the one that didn't match but the wrong one still would have worked and latched if you ground the key tab off the sensor. They weren't necessarily VSS plugs. Some were in the engine bay for other stuff.

Also, it happens to be the same plug (including the key tab location) the vapor pressure sensor on/near your charcoal canister uses if you want to see an exact match on your rig.

Edit- added pic showing the tab.

[cougarfreak]

Just got off the phone with Marlin and there may be an issue in that I'm using the stock t-case from my '97 4Runner driver drop, and not the pass drop earlier model you are using? I'm not sure why this would be an issue as the plug cap is there... If I bought a '97 Taco output speed sensor and cable, bought the VSS from Marlin and hooked it up the way you describe, why not??? Dude on the phone never sold one or had anything to do with one, so I'm curious...

[ErikB]

If you get a speed sensor from a Tacoma t-case, you don't need the one Marlin sells. You are doing the exact same thing MossyRocks did.

The one Marlin sells is a VSS that mounts to a speedometer cable drive gear. Check out the pictures in the Marlin forum link. In your case, you would need a cable drive (the large diameter style) AND Marlin's VSS, but since you don't have either one it would make more sense to just get the VSS from a Tacoma (unless you can't find one used). Brand new VSS's from Toyota are $220. Cable drive gears are about $50 so that is why Marlin's $60 VSS makes sense ($50+$60 vs. $220) if you cant find what you need used.

My t-case already had a cable drive, so all I needed was Marlin's $60 VSS. If I'd known Inchworm had a box of used factory VSS's, that would have been an even cheaper route to go (although I'm not sure it would have cleared my crossmember setup).

I've had trouble getting any worthwhile info from the phone answerers at Marlin lately. The guys that really know what they're talking about are in the back doing the real work. I like their parts, but I try to do my own research before ordering.

I would recommend calling Jim at Inchworm. He answers the phone himself most of the time and will take the time to talk to you. And he really knows his stuff! He has both the large and small diameter VSS's (you need the large).

[Mossyrocks]

what he said.

My transfer case is the factory 97 4runner case and I used a factory tacoma vss. I cut the wires and unbolted it, spliced in the new wires and plugged it in. If you get a taco vss from a junkyard just cut the wires and keep the connector.

by the way, everything is still working great.

[cougarfreak]

NICE!!!!!!!!!!!!!!!! Thank you guys big time!!!! I'll call inchworm and Marlin, this time with the right question "do you have any used Tacoma VSS's I could buy? How much???" TAP had them for $120 (75 for the sensor and 45 to carve the plug outta the harness ) I think TAP has a corneer on the Tacoma market. I have never seen a tacoma or a late model 4runner in any of the PnP's I've been to. I'd imagine they get some, but they don't last long if/when they do.

[neliconcept]

Brad, exactly where was the signal sent to for the speedo anyways? after i did my converison, my speedo still worked until i went snow wheeling then all of the sudden it kicked out. I have the inchworm lefty with an speed sensor already in it, just not hooked up. Im gonna have to do this sooner or later.

[Mossyrocks]

I always ran into that problem with the wheel speed sensors after the swap. They are going into the abs ecu.

[neliconcept]

Originally Posted by Mossyrocks

I always ran into that problem with the wheel speed sensors after the swap. They are going into the abs ecu.

aha! i disconnected ABS from my front spindles when I changed spindles out. However, after a while it still worked? then it suddenly just caked out, thats what i dont understand, however i guess i got some wiring to do (i hate wiring)

[cougarfreak]

My speedo would drop signal when traveling over bumpy roads at high speeds (when I had my 8" still under the rig). It turns out my axle tube was bent and the toner ring on the axle shaft would either hit the sensor (evidence of contact was seen on the toner ring) or would move too far from the sensor. I would stop the vehicle and it would kick back in.

Mossy, you've removed your abs block outta from under the hood, yes? cruise control still works on yours???

I am also curious how you pulled out your gauge cluster to access your wiring to connect the piggy backs?

[neliconcept]

well im wondering if my rear abs sensors have gotten hit or something, i had to pull them when i swapped rear diffs for a 4.56 arb rear. however it still worked after that.

i sorta want m speedo back so i can at least see the mileage being put on, it is my DD.

[Mossyrocks]

Originally Posted by neliconcept

well im wondering if my rear abs sensors have gotten hit or something, i had to pull them when i swapped rear diffs for a 4.56 arb rear. however it still worked after that.

i sorta want m speedo back so i can at least see the mileage being put on, it is my DD.

either do this or wire your rear speed sensors to the front connectors.

[Mossyrocks]

My speedo would drop signal when traveling over bumpy roads at high speeds (when I had my 8" still under the rig). It turns out my axle tube was bent and the toner ring on the axle shaft would either hit the sensor (evidence of contact was seen on the toner ring) or would move too far from the sensor. I would stop the vehicle and it would kick back in.

Mine was doing the exact same thing

Mossy, you've removed your abs block outta from under the hood, yes? cruise control still works on yours???

ABS and cruise are completely gone from under the hood

I am also curious how you pulled out your gauge cluster to access your wiring to connect the piggy backs?

pull the dash panel below the steering column (the large one) 4 10mm bolts. Then the piece around the ignition. Pull the screws from the bezel around the cluster and disconnect the dimmer as you pull the bezel out. (two of the screws are recessed above the cluster) Then youll have 4 screws around the gauge cluster and that would be it.

[cougarfreak]

You sooo rock!!!!! Thank you. I wasn't sure if I was going to bump into some hidden pop off holders or some funky hidden bolts (I haven't taken a look at it yet, but I wanted to prepare myself). Every bit of help in making things go quicker definitely makes Mama happy (Mama's happy = I'm happy... I know, I know, I can hear it now... flame on!!!)

[Dickfoster]

Correction the early Taco's did have a speedo cable. My 95.5 does. I think the switch to all electric came in 97 but don't quote me on that.