2nd Gen Tacoma Speedometer Fix after Axle Swap

I created this writeup to hopefully save time and headaches for others who have speedo/ODO not working after axle swaps. There are likely multiple variations fixes possible for this but i couldnt find them.
- Disclaimer** I am a DIY builder of a Tacoma Rock crawler. I am not a mechanic or Auto Technician. My fix is reflective of someone who doesn’t care about warranties or any factory performance, or any need for ABS. I wanted my speedo to work, and I needed the check engine light to turn off so that I could SMOG my truck here in Cali. I solved this issue by searching the internet, calling shops, buying parts, and spending hours in my garage with a multimeter and temporary wire connections. I am sure there are many variations to this fix. congratulations if you have found another one.

- My truck is a 2007 Tacoma, 4.0 engine, Automatic Trans, with 1-ton Ford Super-Duty axles front and rear, my TCase is a 2007 FJ Cruiser case. After performing the Axle swap, I disconnected the individual wheel speed sensors and threw them in the trash. The remaining ABS sensor wiring I left in-place, and bundled and zip-tied inside the frame rails. I also deleted/rerouted all of the brake lines going to-from the ABS module(anti-skid controller) located in the passenger-side engine bay, but left the module and wiring in-place. All of my brakes are plumbed directly from the master cylinder, I have no-need for unnecessary brake lines cluttering my engine bay in my crawler. My Check engine and ABS lights were on, and speedo/ODO didnt work.

Issue: You have swapped axles in your 2nd Gen Tacoma to units that do not have factory ABS sensors or tone rings. You now have no Speedometer, Odometer, and your Check-engine light is on with a VSS error code, and your ABS dash light is on. Your vehicle was receiving speed signals from the ABS sensors which are now not in use.

My Fix: You can bypass the ABS sensors by installing a worm-gear and speed sensor in the blank port in your factory T-Case and wiring the signal wire directly to your ABS module under the hood. This will send a pulsed voltage to the signal wire coming from the ABS module, and make your Speedometer and Odometer work, and remove the Check-Engine light for VSS. There are likely other locations that you can tap into behind the dash, but I did not explore other wires. It will NOT fix your ABS dash light., i just removed the LED chip from my gauge cluster to solve this.

Part #’s:

- Speed sensor: there are multiple speed sensor part #’s called out on OEM Toyota parts diagrams. I decided to buy multiple 2 different cheaper aftermarket sensors instead of buying the $300 toyota sensors

o VSS option #1: 83181-24070 Genuine Toyota, $300 (didn’t buy too expensive)

o VSS option#2: 83181-24070 Aftermarket, $50(this leaked oil due to bad o-ring casting so I did not use this one)

o VSS option #3: 83181-12020 Off-brand 33 tooth (this worked for me): $20

- Speed sensor 3-wire toyota pigtail, $10 on Amazon

- Speedometer drive worm gear: 33481-35200 $37 from OEM toyota

- Detent ball to drive worm gear: 90360-05012, $3 from OEM Toyota

General Notes:

- Toyota Tacoma’s, 4runners, FJ’s, ect all switched from a gear driven/electric signal VSS sometime in the late 90’s or early 2000’s. From there, most models switched to receiving speedometer signals from the ABS wheel speed sensors instead of the gear driven VSS. The exact timeframe for the above differs on model and engine/tranny configurations and I did not bother to research this. The good news is Toyota kept the same TCase architecture in this Era and installed a block-off port and a smooth collar in the location of the gear driven VSS and worm gear on the output shaft.

- 2nd gen Tacomas, and 2000s era FJ’s and 4runners will commonly have a blank port with a cover located in the output cover of the TCase. This cover contains an o-ring to seal, and is held on by a 12mm bolt.



Fix Detail:

1) First identify that you have the conditions above, and that you have a blank circular port on the passenger cover of your TCase output shaft.

2) Remove TCase rear output cover and install the drive ball #90360-05012, and drive worm gear #33481-35200(see photo):

a. Remove driveshaft, output flange, and rear TCase Cover. There will be a smooth collar located in the place of where the worm gear will go. Remove this collar and verify that the length and inside diameter of the smooth callar worm gear is identical. (I noticed there were multiple part #’s for the worm drive gears, so you need to verify yours fits snugly on the output shaft before installing inside your TCase) Throw smooth collar in trash.

b. Install ball#90360-05012 into recessed notch in output shaft, and slide worm gear #33481-35200 and any factory shims that were removed onto shaft. Verify the ball slid into key-slot in worm drive gear, this gear will drive your electronic speed sensor.

c. Reinstall T-case output cover and driveshaft.

3) Install speed sensor #83181-12020 into the blank port on the passenger side output cover(see photo): Remove the blank cover and throw it in the trash. When installing the new VSS Oil/grease the o-ring and gently slide this into place to ensure you don’t damage the o-ring or plastic gear.

4) Wire the VSS pigtail(see photo):

a. There are 3 wiring pins. 1 is ignition/acc power, 2 is ground, 3 is signal. I found that the speed sensor I purchased had #1 and #3 backwards from the wiring I found on the internet. If you have a 12v battery and a multimeter, you can test this on your workbench spinning the gear by hand. The 12v should “pulse” on the pin that will be the signal wire.

b. Ignition power and ground I routed through my firewall and to the fuse block behind the dash. You are on your own selecting the best location to tap into and proper routing under your vehicle.

c. Signal wire I routed along the passenger frame rail, and up to the back of the ABS module. I CUT the red/yellow wire located in pin position#18 and connected the signal wire directly to the vehicle-side(left the pigtail/module side disconnected. I left the pigtail plugged into the ABS module, but it seemed to work either way plugged-in or not.

5) Test and clear your check-engine light code:

a. My speedometer worked immediately in this configuration, however the Check-Engine light for the VSS I had to clear with my OBD-II scanner, and it has not came back on.

b. My speedo was reading about 5MPH slow at 50MPH, however I am on 40” tires and 5.29 gears. I read internet reports of different VSS parts pulsing at 2x the amount of pulses, which could make your speedometer read double or half the speed. Fortunately I did not have this problem.

6) ABS light on dash: I removed the LED chip from the gauge cluster. But I heard there may be a way to ground the ABS sensor pins at the module and eliminate this light. Too much work for me.

PHOTOS BELOW:

 

Thank you so much for this write up, I just encountered this issue and was really scratching my head over it!

 

Do you happen to know how many teeth are on the gear of your speed sensor? Apparently they can come with varying amounts of teeth, depending on which vehicle they were intended for

 

Appreciate the writeup!

 

Does this also work on the lat 2nd gen tacoma with the canbus system?

 

Has anyone been able to do this swap by bypassing the ABS module under the hood and going straight to the dash or elsewhere in the cab? I've been doing a bit of research in prep for a rear axle swap and found these resources for early FJ cruisers, but without wiring diagrams and pictures it's pretty difficult to try to line up the similarities between the FJ and Tacoma systems. If someone has wiring diagrams for both the FJ and Tacoma dashes to verify the correct pin location in the second reference below for our trucks, it would be much appreciated.
How to disable error lights and wire T case VSS to master cylinder (FJ): https://forum.ih8mud.com/threads/07-fj-sas-help.683291/
How to wire T case VSS to FJ dash: https://www.fjcruiserforums.com/thr...manual-transmission-speed-sensor-swap.765318/

 

I have had this saved from a while ago. Trying to figure it out as well but may be of some use

 

Ask and ye shall receive. I think that's exactly what I was looking for. Thank you!

 

Looking forward to a write up. I haven’t been able to make any sense of it. It’s from a few builds and @6 gearT444E helped compile a lot of it.

 

I was able to find some of those pieces, but couldn't find the thread where the wiring came from. It's probably going to be at least a few months before I even get started, but when I eventually get to it I'll be sure to share my findings.