4LO-Trac & ABS Kill Switch - Why/Why Not?

You're da man!!! Finally we got a ABS KILL SWITCH FOR TRD SPORT MODELS WITH VSC!!! I looked high and dry and couldn't find anything easy and specific so I did my own trials...no grounding wires for me!!!!
Thanks for documenting the procedure..well done.

 

Only reason why I wanted to put ywm on a switch is so that I can run abs and ywm in 4lo. I know it might involve a lot of switch flipping but that is okay.

Btw I have some 18 or 20 gauge speaker wire. Can I use that. I had 100s of feet of normal electrical wire but I used it all for coon traps...

 

Update pics for the Yellow Wire mod.

 

i need help. i wired my abs to a switch that has 3 extensions coming off the back(it is a lighted switch). How do i wire that switch? lol its not turning on and its not reconnecting my abs

 

If you're using a SPST switch like this: http://www.oznium.com/rocker-switch/tech

You have:

(1) Ground terminal (usually on the outside)
(1) Positive terminal (needs to get power from somewhere to light up the switch)
(1) ACC terminal (this normally sends power to the accessory you want to hook up)

This presents a problem as you are not sending power to anything, merely interrupting the circuit/cutting power. That is why I recommended a more simple two-prong SPST switch.

You can try the following:

1.Connect your NEG (ground) lead to the GND terminal on your switch
2. Connect your POS line to the switch from some fused power source (fuse-tap, or from the battery with an in-line fuse holder)
3. Run a T-Tap splice from the LIGHT GREEN wire to the ACC terminal on the switch.

Try that out to see if it works properly, worst that can happen is you pop a fuse, so maybe have some extra 10A fuses on hand (I blew 3 when I was trying to figure out this mod for the first time).

Also, it would be helpful to add more information about the switch you are using, especially if the terminals are labeled or color coded.

 

Okay I'm going to try that. Hopefully tomorrow. My dash looks like a Christmas tree. I have abs light on, maintnance on start up, parking brake, squiggly car.lol
I'm going to check my fuses too. Maybe I blew one.

I also tried to connect my extensions on abs green wire it didn't turn abs off. So I'm thinking a connector isn't working.

My switch is labeled +, A, then some weird combination of lines.

Edit: just thought of something. A t tap won't work because the abs wire will still be connected.

 

Also. I have a switch on my panel that has a grey and black wire from behind that kick panel on a switch. It doesn't do anything? Any idea?

 

That's what I was thinking too, but it's worth a try. You may have to run a different switch or connect it to a relay.

That's most-likely your TPMS reset button, I can't think of any other harness with just 2 wires in that area. Does it run right next to the hood release?

 

It's not my tpms switch. It's a separate switch down on the kick panel

 

pictures are worth a thousand words

 

Okay I'll take pics in a bit. Freezing rain outside.

I have a question. where in my fuse panel can I put in a relay actually ill need 2.

I hooked my abs back up. It just blew a fuse. So everything is working.

 

You can add a Fuse Tap to to any switched power source in the fuse block. I used the "Gauges" slot. Fuse Taps CAN be stacked, but it's kind of close quarters in there so it's up to you.

 

So I've got it all fixed. Got everything working. Both ywm and abs on lighted switches. I tried to rep you but I guess I already did recently. Thanks for the help man

 

I used the power from the abs and ywm to power switch. Ran the ground to the ground. Then I ran the auxiliary on the switch to the unpowered part of the abs/ywm. Seems like common sense but somehow it didn't work the first time.

 

Damn, nice dude! I was wondering if that would work. So the switch is getting it's (illumination) power from the wires themselves? That sounds so simple, but I wasn't sure how it would work.

Good job man

 

I have a different mod that does a similar thing. Instead of doing ym mod I did a mod to the ABS ECU next to the master cylinder in the engine compartment. I spliced into a wire (I forget what color) and wired up a SPDT switch. Here's what my switch does:

Off in 2HI: Normal stock mode
On in 2HI: ABS/VSC/Limited Slip off

On in 4HI: ABS/VSC off, Limited Slip on all the time regardless of speed in rear and front
Off in 4HI: Normal stock 4wd (ABS/VSC on, limited slip off)

On in 4LO: ABS/VSC off, Limited Slip on all the time regardless of speed in rear and front
Off in 4LO: Normal stock 4LO (ABS/VSC off, Limited slip on <4mph, Limited slip off >4mph

Lights that come on when switch is on: ABS, Parking brake, squiggly car
(Same as when you put your truck in 4LO)
They go off when switch is off.

When I'm going in some deep mud the light flashes and beeps at me as I hear the sound of limited slip pulling me through.

Best mod ever. I did it maybe 2 years ago and did some hard off roading with it on and off in all different modes. Works great even with the trd locker in the rear. Gets me through tons of mud and over rocks np. Big advantage over non modded mode. Very reliable.

However, I got bigger tires and I did a short hill climb and tried to get one side of my truck over a rock that I haven't been able to conquer with my old worn out smaller tires and the rock stopped me again. I bumped it a few times (not hard) to try and get rolling up it, but I kept spinning the rear tires and decided to go around it. I got to the top and realized I did something to my limited slip. The lights are stuck on regardless of switch position. Limited slip doesn't beep at me or work anymore.

I am not sure if I burned out the solenoid or something, but I definitely overpowered my limited slip capabilities with the new tires. I don't know if it is an electronic/computer thing where it wasn't calculating the power correctly for a larger tire size or what. I don't even know if you can recalibrate such a thing.

Any suggestions on how to diagnose the limited slip?

 

I'm not sure how you were able to turn off ABS but maintain limited slip. I thought the ABS is what ran the limited slip. Although it may be a little different since the '09+ can still have ATRAC with the locker engaged, so maybe that is why.

You know what the locker is and how it works right? It's not engaged now and you didn't know about it? I know when my locker is engaged all those lights are on.

The only other thing I can think of is to check all of your wiring and make it it didn't come loose or is grounding itself out somewhere.

 

On mine, the ATRAC can't be on when the locker is engaged.

The ABS is on all the time and VSC is on most of the time except in 4LO and when the locker is engaged.

The wire I tapped into sends a signal from the locker to the 4wd ECU then to the ABS ECU letting the ABS ECU know that the locker is engaged. By cutting this wire and installing a switch, you can control when the ABS ECU gets this signal by either grounding that wire or putting power to it.

When in 4LO with the locker engaged, I turn the switch off which maked the ABS ECU think that the locker is not engaged, so it turns ATRAC on, but since it the truck is in 4LO, the ABS and VSC are always off. The locker mechanically splits the power 50/50 with the two rear tires so the ATRAC manages the front 2 wheels and calculates the power to each tire like normal.

When I turn the switch on in 2HI and 4HI, it sends power to the wire and the ABS ECU thinks the truck has the locker on so it turns, ABS and VSC off. The 4wd ECU is not affected so its acts as normal leaving the ATRAC on. So then you have high speed limited slip without having to worry about the ABS sending you into a ditch or VSC stopping you from kicking the rear end out around a corner.

The locker is deff not engaged or I would have felt it on the highway. To be safe I double checked that. It still can only be engaged in 4LO. I have hit the locker button by accident a few times in the past when in 2HI and 4HI and it doesn't engage. The light just keeps blinking, thank god or I would have torn the rear end off a few times. Even if its locked and you try to shift out of 4LO, I don't think it will let you.

I checked the fuses and they all seem to be intact. I'll have to go through and check all my wires. I figured I would throw the question out there in the mean time to see if there was anything else I can check while I'm there. I am not sure exactly what components are related to the limited slip besides the 4wd ECU, and ABS ECU.

 

http://www.toyotanation.com/forum/6...31-traction-control-atrac-hack-writeup-3.html

Tacogrande has some real good info on this. This is how I learned about it. I guess he got it from a similar mod for FJ's.

 

Sounds like you know as much about this as I do, if not more.

On my '05 ABS and TRAC are still on in 4Lo. Like I said I have read (haven't actually tested it) that if you disable ABS then you lose ATRAC and TRAC since they are operated by the ABS.

My switch makes the ECU think the locker is engaged, so ABS, VCS, and all that are just disabled. I basically go to 1 tire fire and I don't think it changes anything when the locker is engaged and I use it.

I also have another switch that when flipped, will bypass the ADD in the front end. With it, I can make the ECU think the ADD is engaged when it isn't and it will allow me to shift into 4Lo but really I am in 2Lo. (Basically the equivalent of shifting an older rig into 4Lo without locking in the hubs). I can just flip this switch while in 2Hi and my VCS off light kicks on and I get Trac in 2wd and don't have to worry about the throttle limiter engaging when wheel spin occurs. I basically gave myself LSD in 2Hi instead of just an open diff.

Also I have done the locker anytime mod so I can engage it in 2Hi.

There are several differences in the ECU's on the 09+'s from the 05-08's so that is probably why our very similar switches do different things. Could also have to do with the fact that my switch will just ground the locker wire and not ground or provide power like yours. (SPST for me).

Do you still have abs during normal driving? Maybe find some gravel or snow/ice and stomp on the brakes and see if ABS engages or not. I'm just confused as to why ATRAC would go out without throwing a CEL or blowing a fuse or other signs showing.