ABS Toggle - one-switch, on-the-fly, for non-e-locker 96-00s
 

NOTE: This is a work in progress. When I'm done, this will be a how-to thread for making an ABS ON/OFF toggle switch for non-e-locker 96-00 T4Rs.

To Operate:
- ABS OFF: click the toggle down
- ABS ON: click the toggle up (or start the vehicle)

Attributes of this method:
- Uses one switch
- On-the-fly control
- Defaults to ABS ON on vehicle startup
- No new wires through the firewall
- Preserves speedometer functionality
- Original factory dash warning light reports ABS status

@steezemcqueen figured this out originally, but with 2 switches and passing wires through the firewall: ABS disable V2.0 for older 3rd gens (On/off on the fly).

You'll need:
1. One "DPDT (on)-on-(on)" Toggle Switch (e.g. ALCOSWITCH A215SYZQ04)
2. Wire* (one color for the ABS ECU power supply, ideally Yellow)
3. Wire* (a different color for the signal between ABS ECU and ABS Actuator, ideally Gray-Red)
4. more to come...

*Wires need to be long enough to reach comfortably from the ABS ECU behind the passenger kick panel to wherever you plan on mounting the switch.

Background:
When you interrupt the Signal between the ABS ECU and ABS Actuator, the system reports an ABS fault, deactivates ABS, and illuminates the ABS dash warning light. In this state, ABS is OFF. ABS will stay deactivated (OFF) even if you reconnect the Signal between the ABS ECU and ABS Actuator.

When you disconnect the Power to the ABS ECU, the system deactivates ABS, illuminates the ABS dash warning light, but also deactivates the speedometer. In this state, ABS is OFF but the speedometer doesn't work. However, once you reconnect the Power to the ABS ECU, the system recovers, ABS is back ON, the ABS dash warning light turns off, and the speedometer works again. This is what happens when you restart your vehicle.

Overview:
1. To turn ABS OFF (and illuminate the ABS dash warning light), we will temporarily interrupt the Signal between the ABS ECU and ABS Actuator (with a switch). See wiring diagram, gray/red wire, GR-R (A16) between the ABS ECU and ABS Actuator.
2. To turn ABS ON (and turn off the ABS dash warning light), we need to make sure the Signal is connected, and then temporarily interrupt the Power to the ABS ECU (with either a vehicle restart, or a switch). See wiring diagram, yellow wire, Y (B10?) to the ABS ECU.

That's it. We'll use a DPDT (on)-on-(on) switch. It's a three-way toggle switch, where the Up and Down positions both spring back to the Center position. See Switch wiring diagram with descriptions.

With this method you simply click the toggle Down to disable ABS and click the toggle Up to enable ABS.

Since the toggle always springs back to the Center position, it's no problem if you forget to turn the ABS back on after riding a trail: every time you start your truck, ABS defaults to ON and is working normally.

NOTE: I'll add photos and a step-by-step how-to when I'm done...

Big thanks to @steezemcqueen , @Nelsonmd , @88toy4x4 , and others for laying the groundwork.

I wired up the switch with a pigtail and mounted it. I haven’t tapped into the ABS ECU yet. I just had a minute this morning so I popped off that panel cover, drilled out a hole for the switch, mounted it, and applied little vinyl letter stickers.

(I’m saving that remaining standard size blank for a rear locker…)

https://uploads.tapatalk-cdn.com/202...77eb22a2c2.jpg
https://uploads.tapatalk-cdn.com/202...eaed2e5da7.jpg

Dumb question but I gotta ask….. why do you need to turn off the ABS?

Not a dumb question.

Some people find that for their driving style, the ABS on our rigs kicks in too early in various low-traction situations, especially in certain kinds of snow conditions or while off-road.

I don't have a big need to toggle ABS, but it's a pretty easy modification with no real downside. I'll be driving with ABS ON probably 98% of the time, and 100% of the time on-road.

There were enough members asking questions and writing tutorials about it over the years, I figured I'd improve on the existing methods and post about it.

Cool. Thanks for the explanation.

I was looking into this modification because I find it really annoying for abs to kick on while Wheeling, thanks for the write up!

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ABS Toggle - one-switch, on-the-fly, for non-e-locker 96-00s
 

Just a warning: I haven’t finished doing this on my truck yet, so I haven’t fully tested it. (Although I can’t see any reasons why it won’t work.)

Please feel free to add to this thread if I missed anything.

Also, I’m considering using a bigger switch with a higher rating. Maybe someone with more electrical knowledge can tell me if the switch I linked to in the first post will handle whatever current will flow through it.

5 Amp switch contacts.. As long as these ecu require less then 5 amps your good. If not, then it's the wrong switch for it.

[ another option is to use a relay contacts instead of a high Amp switch]

I have to look at the wiring diagrams to see how many amps are running these circuits.

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Very good modify for lots of users that off road or want to temporarily disable the abs system.

For example;


From your diagrams the fuse is 15 Amp. So you may Need a switch thst contacts can handle 15 Amp contacts.

You also need 14 garage wire to handle 15 amps.

If amp requirements are higher. Its better to put the current across relay contacts. Then you can use any any switch to trip the telay or relays and you can power the relay off cigarette lighter circuit as they are low current to pull a relay.

As you want the powering circuit to be on when the ignition is on only.

( I didn't verify your current requirements I am basically just trying to explain things work so you may wish to consider in your project) :)

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I agree with brillo’s wiring assessment above. Using the switch to control relays to open the circuits that you want will require additional work and wiring, but will be the safest way.

That's how our trucks are wired. They use relays to active the heavier amperage cucuits. When I build circuits for things that is how I do it. :)

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I do the same, and it's not just our trucks that do that lol

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Well feel free to update this thread if you beat me to it. Either way I’ll update the top of the thread to incorporate the relayed design, and update the diagrams accordingly.

What about for e-locker 4runners?

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ABS Toggle - one-switch, on-the-fly, for non-e-locker 96-00s
 

IIRC, the e-locker ECU should automatically disable ABS during locker engagement.

But AFAIK this method should still work for you if you wanted to disable ABS without engaging the locker, although I’m not sure.