02_Limited

I came across a thread at t4r.org about the VSC system on 2001-2002 4Runners and started thinking... Is there a way to disable the drive by wire for 01 and 02 models? DBW was implemented in the last of the third generations so that VSC could be added into the mix. I know the plights of VSC equipped Toyota owners, and how it cuts power to try to gain traction (far insuperior to ATRAC, which uses the brakes...). I would expect that if you were to disable the DBW somehow, the VSC would no longer work, yet you would still be able to control throttle input because there is still a cable connected to the TB, which physically moves when the gas pedal is depressed (a la 1996-2000 5VZ-FE's).

Would this work, or is this idea completely far fetched? I can't imagine that the drive by wire components interact with much more than the VSC system. Any input is appreciated. Thanks

ozziesironmanoffroad

i know u can do it on the electronic throttles of the newer F150s..... bout 4runners im not sure

mt_goat

From what I've seen the cruise control may also be affected.

02_Limited

I know this seems ambitious but I was thinking there might be a way to do something along the lines of the Andymod, and be able to enable/disable the DBW as you wished, which might come in handy when offroading. Plus, losing cruise control during offroading wouldn't bother me a bit

NicCantDecide

it shouldn't be too difficult...

I don't know about the toyota version specifically, but here are my thoughts:

There has to be a signal wire for the system, once you figure out which wire it is (FSM can probably help) you have to figure out if it activates when neutral or when live.

If it activates when neutral, you just have to have a switch that will ground the wire.
If it activates when live, then you just need to have a switch that'll interrupt the connection from the signal wire.

Toyota's may be more complicated than this but that's the basic principle of most of these systems. There has to be some sort of signal wire that goes to a computer and adjusts the throttle.

DeathCougar

iTrader: (23)

How could you possibly disable drive by wire? Wouldn't you effectively eliminate any way to increase the engine RPM's? Or am I missing something here. You have to have a cable or wires hooked up.

mt_goat

I guess there is still one cable going to the DBW throttle body, kind of a backup throttle cable maybe...not sure. But on the older throttle bodies there were 3 cables attached to the throttle body. Throttle cable, transmisson kick down cable and cruise control cable. So there maybe issues with the auto tranny too.

DeathCougar

iTrader: (23)

Ah yes, i forgot they were only 1/2 drive by wire on the 4runners.

On the Camry, and all the newer cars, they are 100% drive by wire. No cables at all, so if you disconnect that throttle body, you get nothing.

02_Limited

There is one physically moving part on the TB in my newer 5VZ, compared to the 3 (throttle, kickdown and cruise control) on the earlier models. I know that the one cable attached to the TB definitely moves. If I press the gas with the hood up, I can see the cable retracting, slowly turning the "wheel" its attached to, and opening up the throttle

mt_goat

Does it open it all the way? Or is it a limp home thing?

mastacox

I don't think "disabling" your throttle-by-wire system will do what you think it will. My guess is that the cable you're seeing is the kickdown cable for the transmission.

Going by definition, a throttle by wire system doesn't have a cable connected between the gas pedal and the engine. Instead, your pedal moves a potentiometer or encoder, which in turn sends a signal to a box that opens the throttle body (and probably does some other stuff with the ECU as well).

If you disable that system, my vote is your gas pedal will do nothing.

02_Limited

The cable opens the "wheel" all the way when the pedal is depressed inside the truck, so I'm pretty sure that it's not the kickdown cable for the transmission. I know that the transmission is controlled by the ECU (no longer using the input from a kickdown cable), so I figure that the transmission would be unaffected if VSC were to be disabled

corax

Just about every transmission I've seen since the mid 90's is electronic - no kickdown cable, no vacuum modulator - the TCM uses the input from the TPS to control downshifts

millwrightbrian

This is an topic that directly effects my project direction... Does anyone have a 2001 or 2002 4 runner with dbw that they can go look under hood and see if it is throttle or kickdown cable? I bought a 2002 3.4 motor, ecu, and wiring harness for my 1992 truck with auto trans (3.0 to 3.4 upgrade). I was told by local auto wrecker this would work fine, but finding out from thefallman and mtgoat that this setup will most likely not work for me do to this DBW and the new ecu with old AT. I have the one hook up for cable but dont know for sure if it is for throttle or kickdown. if I pull the level all way open the fly inside TB only opens about 1/4 way. When I grab fly with my hand and turn it more I feel a servo type feeling. At least mine is without a doubt fly by wire!!! So my guess it is either a limp mode or kickdown? but I dont really know how a kickdown cable works for sure... I have included a picture of cable setup..

millwrightbrian

Hey bro I just checked mine 4 times and it is impossible for it to open fly more then 1/4 turn and this motor and tb came off a 2002 4 runner. i ask if you are looking inside of tb cause it does move long ways but inside only 1/4 way open. mine is without a doubt FBW and also some cable limp mode or something.... dont take this wrong way I am no expert just my observations... Does anyone know what year the T100 quite using a kick down cable cause I was told my older A340H tranny would work good with a 95 thru 97 ecu and tb?

corax

that's the same way my wife's is300 works - the throttle cable only has a direct effect for the first 1/4 of opening, the rest is all ECU control

look around "my.is" - the Lexus is300, is250, is350, isF forum for some info, I know a few people over there have disabled their FBW, but I'm not sure if they are running a stand-alone or not. For sure if you disable/bypass it, your factory ECU will throw a s**t fit

Ironmike4x4

I've not dealt with Toyota DBW systems, but I know on GMs they have actuators that move the throttle blade controlled by numerous modules and the APPS (accelerator pedal position sensor) so I find this feat nearly impossible, but then again GM likes to overcomplicate everything so Toyota may be different.

mt_goat

Yeah I think it must be a "just get me off the train tracks" thing.

My 2001 tacoma has a kickdown cable, I think they changed the Tacomas to DBW in 03. All auto T-100s should have a kickdown cable.

GSGALLANT

IMO, just do the Andymod and be done with it. Quick, easy, effective.

ETRNL

the easiest way i have found to disable vsc is to throw it low range and lock up the center diff. so maybe you can use a set of switches to fool the computer into thinking you are in low range with the center diff locked. you would still have atrac but no vsc which means you can actually sling mud.