TRACTION GUIDE (TRAC, AUTO LSD, TRAC OFF, VSC OFF, A-TRAC, RR LOCKER

A new thread that modifies a popular one from 10 years ago. For 2012, Toyota decided that 9 drives modes just wasn't enough, so they created a 10th mode!

This is an information post to describe the drive modes and how and when to use them. If your Tacoma is not a 2009 or newer, the information may not apply as some traction controls were options on 2005-2008 Tacomas and may operate differently than the 2009 and newer Tacomas.

This information is designed to assist in using the factory installed systems and in no way is meant to imply that after-market or non-Toyota products are either good or bad.



H2= 2WD High Range, H4= 4WD High Range, L4= 4WD Low Range

VSC is Vehicle Stability Control (keeps vehicle going where intended)

TRAC in H2 is a limited slip system that regulates engine output.

AUTO LSD in H2 is a limited slip system that doesn't regulate engine output.

TRAC in H4 is a limited slip system that doesn't regulate engine output (2009-2011).
TRAC OFF in H4 is the name for 2012 and newer Tacomas and requires a button press. Same function as AUTO LSD but on all 4 wheels. Standard (no press) 4WD TRAC now has engine regulation.

A-TRAC in L4 is a system that equalizes torque across the front and rear axles to keep the truck moving over severe off road surfaces or lack of surface (with only one tire of four on solid ground, A-TRAC can move the vehicle). Some slipping occurs to allow steering and adjust to the surface traction needs.

REAR LOCKING DIFFERENTIAL is available to equalize the torque across the rear axle with no slipping of the rear tires. Steering can be affected, so Toyota recommends use for emergency (stuck) situations.


UP TO NINE DRIVE MODES (2009-2011)*

1) Normal street driving: H2 TRAC ON and VSC is on.
2) Slippery conditions, to get moving from a stuck: H2 AUTO LSD ON (VSC is off under 30 mph). Press VSC button once while moving or stopped.
3) Spinning tires preferred: H2 VSC OFF/TRAC OFF. Press and hold down VSC button 3+ seconds, while stopped.

4) Loose dirt, sand, snow: H4 TRAC ON and VSC is on (2009-2011). Renamed TRAC OFF for 2012+
5) Spinning tires preferred, off pavement: H4 VSC OFF/ TRAC OFF. Press and hold down VSC button 3+ seconds, while stopped.

6) Spinning tires preferred with low gearing torque: L4 (with A-TRAC off)
7) Steep grades, large rocks, deep mud, severe traction conditions: L4 with A-TRAC ON. Press A-TRAC button once.
8) Spinning tires in front only: L4 with REAR DIFFERENTIAL LOCKED.
9) L4 REAR LOCKED and A-TRAC ON. A-TRAC comes on automatically when speed drops to under 3 mph to provide front traction to get you going, again.

ALL Tacomas have 1-3. ALL 4WD Tacomas have 1-6. ONLY 4WD OFF ROAD TRD Tacomas have 1-9.

*2012-1015 Tacomas have an additional mode in H4, called TRAC OFF. Achieved through the quick push of the VSC button. The TRAC in H4 in 2009-2011 has no engine regulation (for stronger traction). In 2012, they made TRAC the same as it is in H2 (brake assist and output regulation) and added the stronger TRAC, achieved with a button push to turn the TRAC regulation OFF... or TRAC OFF Mode (as is AUTO LSD in H2, also known as TRAC OFF on the chart). 10 modes in total!


USING THE VSC BUTTON (SWITCH) CHART:







H2:


TRANSFER CASE CONTROL


SWITCHES (BUTTONS)


VSC OFF (Push and hold down 3-5 seconds of VSC OFF button, while stopped)


AUTO LSD ON (Push the VSC button once. VSC is off to 30 mph)


H4:






L4:






Push the A-TRAC button once while in L4. Push again only to turn off A-TRAC.






Rear Locked (X as in no differential action on the rear)



*In nearly all cases, the standard mode in H2 and H4 will work the best for typical driving in those 2WD and 4WD conditions.

*If 2WD only, you have difficulty getting started because of snow, steep boat ramp or ice, try AUTO LSD. 2WD OFF ROAD TRD Tacomas have a rear locking differential which will provide more traction.

*4WD High, the normal mode is TRAC (but is like AUTO LSD in that no engine output regulation occurs for a strong limited slip for off road conditions). In the 2012+ models, a quick button push is required for this mode, renamed "TRAC OFF".

*4WD Low, I recommend those with the Off Road TRD package to press A-TRAC for the most traction control. All other 4WD Tacomas may find H4 TRAC will out-climb L4 (without any traction control)... That was my findings.



BGrutter created this nice chart:




With so many new Tacoma World members here every day, a need for a clear guide to the traction systems was in order. The post I started soon after getting my truck (on A-TRAC and the other modes), is many pages long and so many replies are off topic, I hope we can have a fresh start without the conflicts of the past.

Again, this is only about the Toyota factory equipped systems.

Thank you all very much!

The photos are from my 2010 Off Road 4x4.
I welcome any 2012 to 2015 Tacoma with a similar style close-up photo showing the TRAC OFF light illuminated while in H4 (4WD-HIGH).

 

thank you David K for your post, first time - new Tacoma owner. was driving in 4 wheel drive last night due to snow and noticed rear wheels locking up when turning, this was not a sharp turn. so if in 4 Hi, should i psuh the button that turns TRAC off? would this keep the rear wheels from locking when in 4 hi?

thanks

 

Hi warrick,
In 4 HI or even LO, the wheels do not "lock-up" but the front and rear driveshafts are locked together. Because the front tires together roll more than the rear, you should only use 4WD on unpaved surfaces or if paved roads are very wet or icy/ snowy. That allows the driveline to not "bind-up". Also, if you try to turn sharply in 4WD and the ground is firm or paved, it will be difficult since the front and rear are locked together. Simply rotate the dial back to 2WD if you feel the binding.

Now, to be clear what the VSC button does, at least in the 2012+ Second Gen Tacomas:
A quick push in H4 puts you in TRAC OFF MODE but does NOT turn TRAC off. TRAC OFF MODE means the engine regulation is turned OFF (VSC is also off but only to 30 mph). No engine regulation gives you more power for the limited slip system to get you moving from a stop in slippery conditions. This is the same in 2WD, but there, it is called AUTO LSD. In 2009-2011 Tacomas, H4 TRAC does not have any engine regulation so no quick button push is needed to make TRAC stronger. Toyota added TRAC OFF in H4 in the 2012+ models and made H4 TRAC the same as H2 TRAC, ie. with engine output regulation (some late 2011 owners reported they have it, too).

To turn the TRACtion control (limited slip) off so you don't have any limited slip action you must stop moving and press and hold down the button for 3+ seconds (until the VSC OFF light comes on). Both VSC and TRAC is turned off in VSC OFF MODE. I personally have never found any use for not having any traction control and the only benefit is maybe that you lose the 'beep-beep-beep' noise when TRAC or VSC is working for you during wheel spin moments.

 

thank you very much for reply, appreciate it

 

Wow. Thank you, David K...that was the most comprehensive write up about the traction systems I have read. Scared the crap out of me the first time I tried to do a donut in the snow and the truck beeped at me and righted itself!

 

Great info. I copied the #1-9 paragraphs and will keep it in glove box. Best write up I have seen

 

Here's a pic of the gauges on the 2012 with trac off

 

I am still hoping to see a factory chart on the 3rd Gen VSC/Drive Modes like the one I posted for the 2nd Gen, above. The TRAC OFF in H4 (compared to TRAC) and if there is any TRAC or TRAC OFF in L4 is the big mystery for the 3rd Gen Tacoma Off Road 4x4s. Reports seem to indicate it is the reverse of the 2nd Gen TRAC OFF. I need to go for a ride with someone in their 3rd Gen who isn't afraid to get it dirty out in Ocotillo Wells. I did the simple climb testing at Devil's Slide and documented how far up each traction choice would take me.

 

Hey my buddy has a 2015 TRD Sport and TRAC OFF comes on any time he goes to 4L. Is this normal? Also is that what the "yellow wire mod" is supposed to fix?

 

Yes, normal. In L4, there are no brake assist features unless you get the Off Road TRD. The mod tricks the computer into thinking it is in H4, so you have TRAC... in L4.

 

This is all amazing. For a complete rookie it’s pretty daunting. Has anyone done a list of each setting and the corresponding condition(s) it would be appropriate for? Just generally speaking?

 

Yes, I think besides my many posts, others have made charts.
The most important thing I wanted to express was that we all should know about these available options and how to activate them, for when you need more than the standard settings.

For me:
*H2 Trac (if the tires slip, I have 4WD, if not go to AUTO LSD).
*H4 Trac Off (for my 2010, there are no options in H4, it was standard in what would later become a selectable mode called TRAC OFF)
*L4 A-TRAC (on). In snow, if needed, also engaging the rear locker will permit wheel spin to clean out the tires and the A-TRAC (only on the front) activate if you get stuck or close (under 3 mph) to keep you going.

I have found no place that 'open differentials' without traction control (VSC OFF) benefits moving ahead.
I also found that A-TRAC works as well and even better than just using the rear locker, since A-TRAC works on all four tires. I only found an advantage to the rear locker in snow so tires could spin more with the traction control trying to brake them. Maybe good in mud, too. However, in sand and rocks, you don't want spinning tires!

 

Great. Good info. All of it. Much appreciated.

 

Wow. My head was spinning when I wrote that request for conditions. Ha. I reread and also read your other thread. You give plenty of conditions throughout. With all the technical info bombarding me I read right past the practical info. It’s starting to solidify now!

 

Great, glad it helped... Just try the different modes and see what works best for you!

 

Thanks for the comprehensive writeup, David!

Question: what does the abbreviation "RR Locker" or "RR Diff" mean? I know WHAT it is, but doesn't one R mean Rear, so what is the second R for?

 

Good question...
I just assumed the Japanese-English translation people simply abbreviated, using the first and last letter of ReaR...???

It's what the post office did with many states when they made two-letter abbreviations.... CA CO CT

 

Now, with a 4th Gen Taco, what changes to the traction choices or operations might their be???

I never got to test a 3rd Gen personally to do a write up, as there was some conflicting findings from those owners. Obviously, the changes include A-TRAC becoming MTS (on automatic trans) with selectable degrees of spin control based on the terrain and CRAWL, a 'cruise control' for slow, low range driving, and the ability to automatically get you unstuck from certain surfaces.