03_4x4Runner

I went out to a sand hill near my house yesterday to see what my new 03 4runner would do in sand. It goes fine on the flat spots, but when getting to any hill where wheel speed is needed to continue climbing, the traction control (or some smart toyota system) kicks in and start applying the brakes, making it hard/impossible to climb in sand.


How can I dissable this. I don't care If I have to pull a fuse, thats no big deal for the few times I go in sand, It would just be nice to know how to get around this. (especially if I'm even in a place where I need to climb a sand hill to continue) thanks

tom4416

If there is a way, the dealers don't know what it is. Since it's all tied into the ABS system, I kind of doubt it. Don't know why Toyota couldn't have given us an override for the traction and skid control (there is certainly enough blank switch plates on the SR5 models!). The dealer let me look at the schematic for the system and it made very little sense to me but we couldn't find a fuse in the system cause I figured I could then run a switch to it. The failsafe is probably built into the ABS control unit itself and therefore not accessible to the consumer. Bad way of engineering off road vehicles while trying to protect the public from itself.

EDGE

You where obviously in 4wheel drive right OK all joking aside I had this problem in snow which is basically the same as you except sand, hit the switch on dash that is to the left of the steering wheel "should have a little 4x4 symbol on it" you should be able to stand on the gas and go up the sand hills, it's not your traction control messing you up it's the VSC "vehicle skid control" I had a similar problem where I could not get through some snow but then realized from reading the owners manual

BigStew

Edge is right on. The switch is the "Center Differential Lock Control". When engaged the VSC(Vehicle Stability Control) light will illuminate, indicating the VSC is DISABLED. This is from page 138 of the owners' manual.

Hope it helps...let us know...

03_4x4Runner

I ment to try that but completely forgot til I got home. But that still doesn't sound right.

Thats only the skid contorl, the traction control seems like it would still be there limiting the tire spin. I don't care if i have to dissable the ABS< it would only be for a short time off road (you don't really need abs off, road, I'm used to it from the Jeep)

I know how to drive off road, I'm just used to having it alittle easier (Well Less complex) in my wrangler.

EDGE

Yeah thats it, it locks the Center Diff:pat: I could not think of that, anyways thanks BigStew for filling that in and next time yu go out you will see the difference, this past winter when we got 2 feet and the plow trucks where leaving 4 foot drifts everywhere I could not get threw them until I hit the switch, works wonders

rwmorrisonjr

Ditto the above for my 2001, which also has the VSC system. When you lock the center diff, it turns off the VSC system, but not the ACTIVE TRAC system which took the place of the e-locker on the 2001+ 4Runners. It works almost as well as a locker, but not the same way since it uses the brake system to compensate for wheel slippage; more like an LSD than a true locker. But I;ve used it to get up rocks & sand and it works fine.

Good Times

yup you prob had a difficult time because of the vsc enabled.

i've read that the mtrac is suppose to actually help. I'm not mechanic so i'm not sure but i've managed to get through some places that i didn't think i wasn't able to do.

in your case, in sand, you really want to air down alot (if not you'll just get stuck). also vsc should be disabled.

ideal conditions would be to have diff locks (front/rear) but unforunately those are not available yet...

try disabling the vsc and airing down alot (8psi or even less if you can - make sure u can air up after though). after that you should be able to manage the hills (unless it's too steep that is).

good luck

Aurora Sandman

I know this is a really old thread, but I came across it doing a search.

I always wheel with the center diff locked, and in my experience, (which has been a significant amount), disabling the center diff DOES NOT eliminate the problem of the computer not allowing spin in sand or snow. A good test of that is to try and do donuts in sand or snow. The computer kills the throttle when it senses spinning.

hillbilly

03_4x4Runner-

I've run into the EXACT same problem when trying to climb a steep logging road incline where I hunt in extreme snow conditions with my '01. I even complained to Toyota about it, with no results. Check out this thread from way back when:

https://www.yotatech.com/forums/show...ht=active+trac

Active TRAC (A-Trac) is a serious pain in the a$$.

PS- Don't worry about not trying the "Center Diff Lock" button. That only disengages the VSC, but does nothing to prevent A-Trac from engaging. The only way I'm aware of to disable A-Trac is to be in 4Lo/Lo with the center diff locked. Anything other than 4Lo/Lo and A-Trac remains active. But then again, 4Lo/Lo provides so much torque that disengaging A-Trac at that point is almost pointless.

fourunnabilly

I didn't read this thread in great detail, but I have been experiencing "engine breaking" from time to time when my traction is bad...essentially just the motor stopping itself. I also get a beeping noise often when I am wheeling. I am pretty sure that when I hit the center locker button and the VSC goes off, these probs go away...anyone else experienced this?? Thanks.

Billy

Good Times

Billy:

Whenever you offroad in loose surface, always lock the center.

This way VSC is completely turned off and you won't have to deal w/ the annoying beeping crap.

Also you get beeping if you don't engage 4lo correctly too (so watch for that). If you use the DAC (downhill thingie), you'll hear that thing beep/yell/crap all over you so fair warning (personally i don't even bother to use that button. much more fun doing it myself - cuz the dac is sometimes too fast going down... )

Aside from that, you should be fine.

You will never hear the mtrac working as that system is integrated into the 4wd system and works in conjunction w/ u driving. it won't beep or do anything crazy. VSC and DAC will do fun stuff to ya if ya don't pay attention

BT17R

I thought someone here suggested pulling the ABS relay to disable TRAC, but don't know if anyone tried.

sfrolich

If you somehow got the ABS turned off you would basically be off-roading with one drive wheel per axle. You are better off letting the system try and brake spinning wheels for better traction on non-spinning wheels.

Scott

Aurora Sandman

Ditto that. Without the ATRAC, you're open diff.

hillbilly, what are you refering to by 4lo/lo? I know 4lo, but not 4lo/lo.

I'm not sure hillbilly is right -- as far as I know, there is no way to turn ATRAC off. (Of course, I don't think I have this lo/lo thing either, so maybe his truck is different than mine. )

As for what fourunnabilly writes, getting a beeping noise often is probably due to not having the center diff locked and the computer not being able to cope with the torture. For those that don't know, (and someone can correct me if I'm wrong), what that means is that your center diff/transfer case is acting as another open diff. So if there's less tire traction in front than back, torque is tranfered to the front (just opposite of what you'd want). Now ATRAC will try to correct that, but it really works better if you have your center diff locked. The only time to not have it locked is if you're on pavement or a surface that doesn't give, because your front and back axles need to travel at different speeds when you make turns.

FirstToy

In sand, I have run with the diff lock on (VSC off) without problems, beeping or anything.
I can do "burnouts" or whatever.

With the DAC on, I don't get any beeping. It makes noise but that's the ABS going off.

zedex

Build a sine wave generator and splice into the abs. The computer sees a sine wave generated by the wheel sensors spinning so you could tap into the abs with a higher frequency sine wave. The computer would think the wheels are going alot faster than throttle so you could pin it to try to catch up to the sine wave. Its easy!

hillbilly

Sandman-

4Lo/Lo = 4 wheel drive engaged and transfer case in Lo + transmission in Lo (1st gear).

I'll see if I can verify where I found/read about this, buts its my understanding that as long as VSC is disable and the T-case/tranny are both Lo, it will disable A-Trac. The only other way is to disable A-Trac is to overheat the ABS system (by excessive use). But that will only temporarily disable A-Trac, since it will automatically re-engage once its reach an acceptable temp.

Darren

Not the case.

hillbilly

Point taken Darren. Its been awhile since I've looked into this, and as I stated earlier, the above was how I understood how it worked. I'll give mine a run tonight/tomorrow and see what 4Lo/Lo produces. If the tires spin in 4Lo/Lo without the ABS chattering, that indicates A-Trac is off.