A-Trac in 4-Hi?

[westwind77]

Also for what its worth to the prier posters I would want it to monitor and brake the wheels that slip at higher speeds so you don't start to slide (ins't that the whole point of active traction control)

Well that is where VSC & TRAC come into play working as a team (TRAC only if you are applying throttle) If you are meaning 'slide' as in the whole truck Vehicle Stability Control (VSC) then takes the controls and (as best it can) will keep it from 'sliding around'

I went from a Durango that in 2H or 4H if I went around a corner too fast the truck would 'slide'. I tested out the VSC control in the snow with the new 4R and wow, it kicks in fast and does not let the truck slide at all. If I remember right these things have sensors that take into account your steering column postion (how much it is turned) and then it will also monitor if the vehicle is actually making the turn you are trying to along with your speed. If all of these little numbers and calcs dont match up the system (VSC) kicks and will make adjustments so you stop sliding.

 

[Uneek]

I bet there's an easy fix to getting it to work in 4-hi too. It's probably a 12v signal that's sent to the a-trac control indicating that the vehicle is in 4-low and by pressing the a-trac button it allows it to come one. Without it being in 4-low and that signal not being present, it won't activate A-trac, or something like that. I wonder who's willing to try to find it? Chris

That was the case with the rear diff lock for the 4WD Tacoma.

The 2003-07 4Runner was similar to disable VSC, telling the ECU that the center diff was locked when it really wasn't.

 

[4Funnr]

I'm confused help me out. I thought that A-Trac was turned off automatically in 4lo so that the wheels could spin and pushing the button simply turns it back on. A-Trac (to me) means active traction control which I thought was alsways on unless you put it in 4lo. You can turn it off in 4hi by stopping and holding the trac. button for 3 seconds. Am I missing something, or what is the difference between A-Trac and traction control.

You are confusing Vehicle Stability Control and TRC (traction control) which are always on in 2WD and 4Hi unless you turn them off. A-TRAC is active and can only be turned on in 4Lo, which turns off VSC/TRC.

 

[4Funnr]

We have a limited and I can make the wheels spin when icy and the traction control kicks in (just like my 08 Tundra) and makes grinding noises and all kinds of ruckus. If you stop and hold the button for 3 seconds it turns that stuff off so the wheels are free to spin. For fun I put it in 4lo awhile back and it says TRAC OFF on the dash and when you push the button that goes off and it monitors and brakes the wheels that spin again. So my guess is its always on unless you put it in 4lo then you have to turn it back on if you want. Also for what its worth to the prier posters I would want it to monitor and brake the wheels that slip at higher speeds so you don't start to slide (ins't that the whole point of active traction control)

You are describing TRAC and not A-TRAC. They are 2 different things that Toyota is confusing about unless you RTFM.

Also, it should be stated that pushing the TRAC-OFF button will only turn off VSC. You must hold the button down for 3 seconds to turn off both VSC and TRAC.

 

[ravencr]

Great info guys. This is exactly what I needed.

Chris