TRAC functions: on and off

mywife's4runner

New member
My wife just picked up our(read her) new 2011 limited 4wd. I have been trying to figure out how all the 4wd functions work and have learned alot. my question still is when TRAC is on it reduces engine power and moves torque to other wheel right on both front and back axles?, OK when I turn it off, I keep power and can spin the wheels, but is it now a open differential or do I still get limited slip, and is it on both axles. If so what is the difference between that and A-trac when in 4low?

I could not seem to find the answer here and I RTFM, and TFM sucks

Thanks
 
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TRAC basically hits the brakes to stop the spinning wheel from spinning. This essentially transfers the power to the wheel with more traction. The diffs are open with it on or off.

ATRAC (advanced traction) attempts to act like a "virtual" limited slip diff. Essentially it is more aggressive than TRAC.

I believe both of these systems only work on the rear wheels.
 
so let me get this straight if I Turn TRAC off then all I have is a 2 wheel drive vehicle? one in the front and one in the back, but I will have full engine power

also TRAC modulates engine power and brakes, whereas ATRAC does not- only applies brakes

Seriously Atrac only work on rear axle? then that means you only get one drive wheel up front. THat seems real odd for such a off road capable vehicle
 
TRAC basically hits the brakes to stop the spinning wheel from spinning. This essentially transfers the power to the wheel with more traction. The diffs are open with it on or off.

ATRAC (advanced traction) attempts to act like a "virtual" limited slip diff. Essentially it is more aggressive than TRAC.

I believe both of these systems only work on the rear wheels.

Oh...I didn't realize that it only worked on the rear axel.
 
I don't think the rear wheel comment is correct. Search youtube and you'll see it in action on the front axle.
 
TFM states that ATRAC stops the spinning of 4 wheels, so I assume this means it works on both axles. now the TRAC it really says nothing at all on how it works or what it is doing. Why is there not a manual somewhere that explains the workings of these functions?
so it look like to me if you want "limited slip diffs"(in quotes b/c I understand it is braking applied to an open diff) you have to be in 4low, with ATRAC on (the system automactically turns off VSC and TRAC) if ATRAC not on you have open diffs. if your in 4high locked then you either have the choice of "limited slip" (back or both axles? don't know) with reduced engine power- which is TRAC or open diffs with full engine power- TRAC off

I would just like to find a source where these features are actually explained, but I can not seem to find any technical info?

Is that too much to ask?
 
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I would think it's all 4 wheels when the Diff is locked. Not sure if all 4 all the time in the Limited but I think so.

Toyota's explanation....

TRAC
Toyota’s Traction Control System continuously monitors the wheels whenever the vehicle accelerates. As soon as it detects that one or more drive wheels is starting to spin, it applies the brakes to the wheels and controls engine output to help the wheels better adhere to the road surface.

A-TRAC
More aggressive form of TRAC & for 4WD OFF ROAD use only. Does the same thing as TRAC except it doesn't cut/control engine throttle. Instead, it transfers torque from slipping/spinning wheel(s) to non slipping wheel. This gives added traction & forward momentum to overcome Off-road obstacles. This can only be engaged while in 4LO.
 
I don't think the rear wheel comment is correct. Search youtube and you'll see it in action on the front axle.

I think you are correct. I forgot that I have seen ATRAC definitely working on the front. I won't commit to saying regular TRAC works on the front though :biggrin2:
 
I think you are correct. I forgot that I have seen ATRAC definitely working on the front. I won't commit to saying regular TRAC works on the front though :biggrin2:

TRAC works on the front & rear when in 4H and only in the rear in 2H, for obvious reason.

If the information in not in the manual, or the forum, it is elsewhere on-line. If all else fails, test it out for yourself.

Besides, common sense tells you if you were in 4H what good would it do to cut the power to the rear wheels and leave the front spinning wildly out of control.

I have tested all of my systems, a number of times, in the snow/sand/ice to see exactly how the function, that way there are no 'surprises' when I actually need to use them.

**On a side note, I know this have been brought up many times but, people please use the search function to find the answers here 1st. There has been a LOT of general repeated questions lately, which I know the answers too, but after posting the same information over and over and over one gets tired of 'wasting their time'. By the looks of what I see I am not the only person either. There are a number of members here that really know their stuff and previously answered questions to help people out all of the time, but they have greatly reduced that. I have a strong feeling their reasons are the same as mine, and it is not like they just don't come here anymore, they still post their own stuff frequently. I also noticed a lot of 'nice' people 'trying' to help out, which I will say is good to see in this world, but some of these people really don't know all the facts resulting in a lot of misinformation getting spread around in the beginning until someone steps up to correct things and set the record straight. Little if anything has changed on the 4R since I picked mine up in 11/09, trust me, pretty much every 'general informational' question HAS been asked, many times over. The information is on here, just take some time and look for it.** End rant - Happy Tuesday everyone - drive safe in the NE tomorrow!
 
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**On a side note, I know this have been brought up many times but, people please use the search function to find the answers here. trust me, pretty much every 'general informational' question HAS been asked, many times over. The information is on here, just take some time and look for it.** End rant - Happy Tuesday everyone - drive safe in the NE tomorrow!

I am used to Internet forums. So I am not a newbie trying to waste peoples time. I promise I looked for the info and found alot of good stuff. Just need a few more answers

I have searched both here and on the Internet. On here about the only thing I can find on turning off TRAC is can you do it? Well we know you can now. that may have been a problem in the past. My real question is. ( cause I looked up and learned the rest already( like how it works) is when I turn trac off with locked center diff will I only get power to one wheel in front and back right? It's a simple question. And I do néeD to test all this out but someone most know the answer already. if it is here I could not find it. If you do I would like you to let me know the link
 
I am used to Internet forums. So I am not a newbie trying to waste peoples time. I promise I looked for the info and found alot of good stuff. Just need a few more answers

I have searched both here and on the Internet. On here about the only thing I can find on turning off TRAC is can you do it? Well we know you can now. that may have been a problem in the past. My real question is. ( cause I looked up and learned the rest already( like how it works) is when I turn trac off with locked center diff will I only get power to one wheel in front and back right? It's a simple question. And I do néeD to test all this out but someone most know the answer already. if it is here I could not find it. If you do I would like you to let me know the link


I agree, there were other questions I have had in the past and I spend hours going through the search results with lots of useless threads and maybe a little bit of information.

I think It might be a good idea to get a Q&A Page where people go to first before posting. Would be easier than combing through pages and pages of search results.
 
TRAC works on the front & rear when in 4H and only in the rear in 2H, for obvious reason.

If the information in not in the manual, or the forum, it is elsewhere on-line. If all else fails, test it out for yourself.

Besides, common sense tells you if you were in 4H what good would it do to cut the power to the rear wheels and leave the front spinning wildly out of control.

I have tested all of my systems, a number of times, in the snow/sand/ice to see exactly how the function, that way there are no 'surprises' when I actually need to use them.

**On a side note, I know this have been brought up many times but, people please use the search function to find the answers here 1st. There has been a LOT of general repeated questions lately, which I know the answers too, but after posting the same information over and over and over one gets tired of 'wasting their time'. By the looks of what I see I am not the only person either. There are a number of members here that really know their stuff and previously answered questions to help people out all of the time, but they have greatly reduced that. I have a strong feeling their reasons are the same as mine, and it is not like they just don't come here anymore, they still post their own stuff frequently. I also noticed a lot of 'nice' people 'trying' to help out, which I will say is good to see in this world, but some of these people really don't know all the facts resulting in a lot of misinformation getting spread around in the beginning until someone steps up to correct things and set the record straight. Little if anything has changed on the 4R since I picked mine up in 11/09, trust me, pretty much every 'general informational' question HAS been asked, many times over. The information is on here, just take some time and look for it.** End rant - Happy Tuesday everyone - drive safe in the NE tomorrow!

His subject was clear, if you didn't want to waste your time, don't click the link. I have done searches in the past and it's been tough to figure things out. Can you give us a list of who we should listen to and not listen to, you know, to save time when we are doing searches? Thanks
 
I agree, there were other questions I have had in the past and I spend hours going through the search results with lots of useless threads and maybe a little bit of information.

I think It might be a good idea to get a Q&A Page where people go to first before posting. Would be easier than combing through pages and pages of search results.

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