Ducky,
Thanks for keeping up with this. It would be glorious indeed if the 4WD and 2WD models of the same year shared a common wiring harness.

I've long had visions that a plug is hanging somewhere behind the dash waiting on a 'TRAC OFF' switch to be plugged in....

Andreas

 

Ducky,

So your theory is that possibly we could get the 2wd trac switch, plug it in to the ecu, and have it function w/o any other mods necessary?
Wouldn't that be convenient!

Dozer

 

It's a Theory... (or is it a hope) in either case, I'm hoping that just like most manufacturers they use (or reuse) the same exact ECU in all models, so they dont have to remanufacturer anything, but then on the flip side of the coin, why didnt they just put in a button from the get go... oh believe me, it's just a hunch, I figgure I have a 50/50 shot.. either its the same one they just didnt add the switch or its different... but why in the wiring diagram would they show a 2wd disable switch on the same ECU for the 4wd? If it were different there would be a different diagram all together... Im just hoping all i need to do is solder, Im hoping the pins are exposed and I dont have to do some drilling or something to get where i need to.

I haven't had time yet because of work to actually open my kick panel.. but Im hoping i will soon... just for the preliminary looksee...

 

Ducky,
Any looksee-ing yet....

Andreas

 

Do you know How cold it is outside? =D

I will I plan on trying to setting aside some time this weekend to look at it... Digi camera ready =)

When I get home its dark so I don't like to work on it late...

 

Well My vehicle is just a Spitting image of any kind of diagram they have...
(those who have seen my rig personally know that its different with all my abs stuff on the brake cylinder...) no luck not in kick panel or anywhere on that side... there is a box attached to my brake cylinder with a whole mess of wires comming off though... im thinking i might be brave enough to pry (unscrew) that box to see what it is... ill post pics as soon as i get em.

 

Ok took some pics.. not any closer yet...

This is what my Brake cylinder looks like...



Here's it more towards the side... might be hard to see but that's the box Im opening... mounted on the side of my cylinder.



And WHAT THE HECK IS THAT?!?! def. not what i expected to be behind the cover... guess it's time to do some more searching...



Frankly im still at the "Where the heck is the VSC ECU" so that's where i am...

 

Just so you know... It was the Hydralic Brake Booster that I uncovered =D

 

OMG...


Acording to this...

V16, V17, V18, AND V19 Are the VSC ECU.... /Cry

V14 is the VSC Buzzer...

Part numbers:
V16 - 90980-11935
V17 - 90980-11476
V18 - 90980-11637
V19 - 90980-11638

I also know where the Actuators and Buzzer and Sensors Are... I have no idea how that diagram seperates into 4 seperate units... More investigation Ahead! I WILL DISABLE YOU DAMMIT!!!

 

Me Again...



If you look at the Acrobat File i first posted... The Switch (T8) goes to the pin "26"? marked "C". Well I didn't notice till now that "C" corrilates with V18.. If you see that key right on the ECU pic...

So... V18 is the one the switch goes on... I need to find it now...

PS Am I the only one doing this?

PSS Also if you look... The other side of the Switch goes to "i 10" which in the key Is a specific Splice Point in the "Cowl Wire" Harness... Whereever that is...

 

Me Again Again!





Well I guess that sorta Explains where the other end of the switch goes... Kinda.. Not a good pic of the Splice Point...

 

Ducky,
Your investigative prowess is not going unnoticed! Thank you so much for forging ahead and trying to find a solution to 'our problem'. A fairly clean solution utilizing the factory 2WD "TRAC OFF" switch to kill both TRAC and VSC would be cause for a huge celebration.

To those that say, "You can turn VSC off by engaging the center diff lock," I say, "Fine, but there are 2WD times where one simply wants to shoot rooster tails of crap all over the place, etc, etc."

Cheers,
Andreas

 

Go Ducky Go!! I've been watching your thread w/eager anticipation since Day One, and am confident your diligence will result in a "correct" way to defeat the TRAC Control. Then, (hopefully ) Good Times and some of the other 4th gen innovators will fine tune your findings to work with the 4th gens.

 

Thanks for your investgation Ducky! I wish I could be some help. It would surely be a momentous day If you figure this out.

Dozer

 

Went out this afternoon on a snowy slippery side street. While in 4H, I punched the pedal and as expected, TRAC/ABS kicked in almost instantly. I then locked the diff and tried again, but not as aggressive as the first time. The wheels spun for a second or two (longer than the first test) and then TRAC kicked in. The third time, I left the diff locked and punched the gas hard. Man, did this thing go wild! 4 wheels just burning up a storm. No TRAC! No ABS kicking in! BUT NO CONTROL either!

Within seconds, I was heading sideways (passenger first) down the street with a parked car approaching fast. My wife was freaking out as she wasn't expecting this. Honestly, I wasn't either, but wouldn't let on. I think I have a low right rear tire. I turned into the slide and soon was back in control.

My limited test confirmed what I suspected. Imagine you're out on an off road venture with 10 miles of slippery snowy road ahead of you. Do you want to be punching the gas the whole way? Not me, Man. The 4Runner will be in a tree or ditch in no time. Slacking off the gas may result in getting stuck.

Would someone be out in such adverse conditions? Probably, at least in areas I've been it's very likely to occur. High rpm's on ice and snow is not the way to go. There has to be a way to install a switch to turn TRAC off/on on demand. Dang, there's a button to kill TRAC in most cars today why wouldn't Toyota follow suit in this rig?

 

Just downloaded a 2005 Pocket Reference Guide from 'http://www.toyota.com/html/owners/.

There seems to be an Active Traction Control (ATRAC for 4WD as opposed to TRAC for 2WD) button on the '05 model. Anyone know about this yet? It appears to be a button that will do what we're searching for on the 4th gens.

 

Appears to be for an electric limited slip, and not the ATRAC itself. The LS is probably a new '05 option that works with the ATRAC system, but is not ABS-related.

 

Go
Ducky, i am sorry I have nothing to contribute. I dont have any wiring schematics, and quite frankly if I had them I think you would do better than I could any way. YOu got a lot of followers and support. Thanks for all your hard work.

 

here's some motivation to keep trying...

 

Except it would say TRAC off too, and be in 2wd!