A-TRAC/TRAC/AUTO LSD Explained (Easy to understand, I hope!)

With quick push I get a "Trac off" light & with a push and hold I get both "Trac off" and the "vsc off" light/symbol.

 

@ whippersnapper - Thanks for trying - but I don't know either. I'll check it out again in the AM. Anybody got some thoughts I'd appreciate hearing.

 

HERE, GO HERE (link in my sig.) for crisp and clear details in one page: http://www.tacomaworld.com/forum/2n...-controls-trac-auto-lsd-trac-rear-locker.html

Briefly right here:

In H4 you are in TRAC normally (TRAC in H4 is the same as AUTO LSD, but on 4 tires, ie. no engine regulation).

You can shut off TRAC (which also is cal;led VSC OFF MODE) for plain open differential action (ie. spinning tires) by stopping truck and holding down the VSC OFF switch for a few seconds. Pressing that button again or re-starting your truck will put you back into normal TRAC (and VSC) ON MODE.

So, the answer is only 2 drive modes in H4... Traction Control and VSC (both) on or off.

Only in 2WD 'AUTO LSD' (traction control without engine regulation) does VSC turn off with traction control staying on, but VSC will come back on at 30 MPH.

At least that's what I have found out so far!

 

What is a TRAC OFF LIGHT? My 2010 doesn't have it, or I haven't seen it. There is a light that comes on when VSC works along with that beep-beep-beep. That I didn't have a photo of in my link, but you can see where it is above the VSC OFF light.

 

Thanks a lot for the reply, but... I just went out to check again, to make sure I wasn't seeing things. In my 2012, the following is what I get:
H4 one quick push of VSC button: "TRAC OFF"
H4 hold VSC button in for several seconds: "TRAC OFF" and "the vehicle with squiggly lines under it" (VSC Off).

I'm assuming (haven't been able to test) that the quick push gives me LSD and no engine regulation??? The push and hold is open diffs??? Perhaps this is new on the 2012's??

The H2 seems as described in this thread:
In H2 one quick push of VSC button: "Auto LSD" and "Squiggly Car, etc"
In H2 hold VSC for serveral seconds: "Trac Off" and "Squiggly Car"...

Again, any input is greatly appreciated..

 

Hi Ron,

In my 2010: In H4, the button does nothing with just a quick push (that only works in H2 to give you AUTO LSD). H4 already has traction control without engine regulation as the normal mode (and it really improves driving off road over my previous trucks). Hold down the button, when stopped for a few seconds, turns off the traction control and the VSC (Vehicle Stability Control). A quick press takes you back to the normal Trac On mode, or re-start the truck.

In H4 (4WD HI), you normally have 'LSD and no engine control', using your words.

Only in H2 (2WD) do you have a choice of TRAC with or without engine control: Normal is TRAC with regulation. A quick push is TRAC without regulation, called AUTO LSD in 2WD.

In L4 the normal mode is no traction control, unless you press the A-TRAC button to have SUPER traction control that is much closer to lockers on all 4 tires than LSD.

 

Hey David,
I really appreciate your help - not just this matter, but this entire thread... very informative. I understand what you and others are saying, BUT... when I'm in H4 (4WD High), I can give a quick push on the VSC Button, and a light comes on that says "TRAC OFF"; I can also push & hold and get a "TRAC OFF" AND "the squiggly vehicle". Do you think this is new on the 2012's, or perhaps some "unique glitch". I also checked my owner's manual - it does not help as far as what these modes are doing (or for much of anything - lol), but it does confirm there is a "TRAC OFF" light. Again, I welcome any thoughts, suggestions... Thanks

 

Sounds to me like they added the ability to turn TRAC off independently from VSC, as well as an added TRAC OFF light.

 

I believe this must be the case - which really brings me to the root of my original inquiry. What does having the ability to turn off Trac separately from VSC gain you? In what type of situation would you want this ability?
And I assume for normal 4WD Hi actions, you would leave everything in the default position - nothing turned off??

 

Oh nutz, now I need to trade in my perfect 2010 for a better 2012!!

Yes, I know what they did... or maybe not? The pain of TRAC + VSC in H4 is hearing the 'beep-beep-beep' of the VSC. We don't always or ever need VSC active when off roading, but TRAC does improve traction greatly over open differentials.

Could you be mixed up on the two, because turning off VSC but leaving TRAC on would be great (we can only do that in 2WD with AUTO LSD under 30 MPH)?

 

Or maybe 11 ??!!


http://www.youtube.com/watch?v=UeOXsA8sp_E

 

I'm mixed up about a lot of things, but I've checked and rechecked: 1 quick push of VSC button shows "TRAC OFF"; push and hold VSC button for several seconds shows "TRAC OFF" and the VSC OFF (vehicle w/squiggles...). I agree that VSC off with the TRAC on would be logical, but that's not what the lights are telling me.

 

From Page 202 of the users Manual
"If the vehicle gets stuck in fresh snow or mud, VSC, Trailer Sway
Control and TRAC may reduce power from the engine to the wheels.
You may need to turn the system off to enable you to rock the vehicle
in order to free it."

Seems stupid to me. I agree TRAC on and VSC off makes More Sense. We need someone to hack the micro-controller code in the 2012 Taco.

 

Hearing that "beep beep beep" on the trails means I'm having some fun!

 

I hate that beeper in winter , I turn it all off

 

lol this is greatt!!! 11!!!

 

My wife hates it, but I think Spinal Tap is a great movie for perhaps different reasons! I actually went to see them in concert... was about 1989, I think? They really play and sing their own music... great stuff.

 

Well, I've had the 2012 TRD OR for about 6 mos now, but have only had the time to take it out on trails a couple of times. I drive in 2H w/VSC off as far as I can go just to see what it takes to make go 4H or even 4L. I've been steering toward the moderate to difficult trails listed in my giant book of trails, and I have yet to find anything that requires even half of what the Taco is capable of. My conundrum is that the terrain that would require all of the extra traction probably also requires armor and articulation that my stock truck does not have. BTW, the DAC is bada$$! It sucks when your trying to ease down something rough and steep in 4L and your foot slips off the brake and you're bouncing around trying to find the pedal again.

 

Hi Zoltan, actually the opposite can be true, as well... You see, the reason for a lot of that armor is with less traction, one must employ speed and power to negotiate terrain obstacles. With speed and power come damage or the need to prevent body damage.

My truck is a pure stock 2010, and because of A-TRAC in L4 and TRAC in H4, there is little to no spinning of tires or traction loss. I can slowly climb very steep grades that have ruts or loose rocks which would normally place tires into low traction situations, and with OPEN differentials, allow them to spin and the other tires do nothing. Even with 4WD, the lack of traction control or lockers would mean a bon-zai approach to climbing such a grade would be needed, and that is when damage can occur.

The 4WD Off Road TRD Tacoma has a locking rear differential, and that alone can make all the difference in the world. But, in even more extreme conditions having control on the front tires can be a benefit. Instead of a front locker, with its affect on steering ability, Toyota uses Active Traction Control that automatically matches tire rotation across the axle to create the traction ability of a locker, but frees up when the traction is achieved so tight trail steering can be achieved (without turning anything off or unlocking differentials). Sure there is some slipping between locking so it isn't as 'smooth' as a front locker... but you will get through, just the same.

The best part is you get the A-TRAC at NO ADDITIONAL COST with the Off Road 4WD Tacoma... and it is covered by the factory warranty.

The best part for us without the budget to 'highly modify' our trucks, is we can safely and slowly get over nearly any rough terrain or traction situation. I haven't found anyplace my truck would get stuck with the A-TRAC from deep sand to deep mud to the worst off road trail in Baja, the road to Mission Santa Maria!

 

WOW