3rd Gen Traction Control Modes Explained

Good info..
Explains alot. Thanks.

 

For someone who's had 4 wheel drive trucks for thirty years, this thread illuminates just how far these systems have come. Hard to get my head around all the options for specific terrains.

As someone new to Toyota, the first page is an excellent "how to" reference. Does a much better job explaining the intended purpose of the individual systems and how they play together.

Thanks Doggman, appreciate your work.

 

On a 460 anyway DAC is more or less a crippled version of CRAWL. The big difference being that CRAWL works both the brakes and accelerator while DAC only does brakes. On either system it is working all the brakes independently in ways a human really couldn't.

In converting to Crawl on a 460 it would appear you are just selecting a different profile in the ABS Skid ECU and using some different pins on the center console switch and connector in interacting with that ECU.

'08-'11 Land Cruiser and LX 570 had 3 speed crawl while 5 speed crawl was added to '13+ models. 4R crawl was 5 speed as well in 2010+ and FJ crawl showed up in certain package in 2013.

Crawl speeds are roughly 1-5 MPH over the 5 speed selection. I thought I read in some technical documentation the speeds are slightly more or less at each selection but can't find that data at the moment. DAC is fixed at around 3 MPH and of course only downhill.

 

tracoff, vsc Long push doesn't work for me in 2wd on my 2018 sr5 4x4. I tried it and there is no difference between the short press. Slip indicator still comes on and throttle is modulated. Any ideas?

 

Are you long press at a full stop?

Please provide pictures or exact symbols shown at short and long press.

Are you getting 'auto lsd' are you getting 'trac off' light ?

 

So today

So today after work I was stopped at a light, in drive, and held it for maybe 5 secs and I got trac off. I honestly have no clue why it didn't work before since I was holding it for 10-15 secs and no change. The only difference was that day there was snow on the roads and the traction control kept kicking in. I'm 99% sure I was completely stopped when I tried it as I was in the cul-de-sac. I wonder if there is a cool down period or something if you were just recently slipping? Who knows, maybe I wasn't completely stopped or I had it in neutral (don't know why that would matter.) I'll try and recreate it next time it snows. For now well just chalk it up to a fluke.

 

Also I just hit 5k miles and reset my maintenance light so maybe that had something to do with it?

 

Wait, so can MTS and CC can be enabled at the same time?
According to the chart it can.. has anyone tried this?

 

Yes.
Yes (but not on terrain, so I didnt figure out if there is a difference).

I dont remember details about it any more (stupid getting old sucks), but take a look at this post, and the next few by me after this one...

https://www.tacomaworld.com/threads...l-modes-explained.530695/page-7#post-17023370

Truck definitely has CC with MTS on and CC with MTS off, but I didn't figure out if they actually do anything different. I dont think they do... I think it is just the ECU remembering your MTS selection for the moment. To get the two modes, you have to first have MTS on or off, then turn on CC. Once CC is on, you cant change the MTS.

 

Cool! Thank you!

 

NP
So just to clarify, when CC is on with the MTS OFF, I know that the truck is certainly braking the free wheel.
I don't know if MTS ON, CC ON produces any more agressive results, but I doubt it.

 

I want to try all this now. I have yet to use my CC or MTS. In fact...
I haven’t even had the truck in 4lo yet

 

Just to provide some sort of benchmark, to see which drive mode gets the truck further, what I did was go to the base of a steep pitch up (side of a desert hill), sort of a sand dune/ dry mud hill.

From a dead stop, I climbed up as far as the truck would go in each of the drive modes. A colored marker flag can be helpful. Once tires spun or the engine could not move the truck further, I marked the point or noted the tire track position. I did not drive repeatedly over the same track since it was compacted by the truck's weight. The A-TRAC and A-TRAC + locker were pretty identical for being the best at climbing. Of interest H4 (with TRAC or TRAC OFF as it was called in 2012) outclimbed L4. This was proof at how improved traction control was over open differentials without traction control even in low range.

For me (as a 2010 owner) personally, the biggest mystery is:
1) The difference between TRAC and TRAC OFF in H4 (2012+ 2nd, & 3rd Gen)
2) Is there TRAC or TRAC OFF in L4 (3rd Gen).

In H2, we are normally in TRAC and need to press the button for AUTO LSD (also called TRAC OFF for 2nd Gen) to enhance the limited slip system, making it stronger.
My logic is that when TRAC OFF was added to H4, it would have the same enhancement? TRAC was limited slip with engine regulation and TRAC OFF (AUTO LSD in H2) was limited slip with the regulation turned OFF.

So, young grasshoppers, go to the base of a steep climb and compare H4 TRAC to TRAC OFF. Then compare the MANY potential L4 modes, especially if you have the Off Road TRD... The 2nd Gens have no traction control in L4 except for the Off Road's locker and A-TRAC. The other models did a wire mod to trick the computer to give TRAC in L4.

*Standard L4 (no button push, what lights are on?).
*L4 quick push (does any light come on?).
*L4 long press (does any light come on?).
*MTS/ A-TRAC
*CRAWL
*MTS & CRAWL
*Rear Locker
*Rear Locker & MTS
*Rear Locker & CRAWL
*Rear Locker, MTS, & CRAWL

 

Tagged

 

Is there no one who can do this? We traction nerds want to know!

 

Sorry! I have been wanting to find a hill like this, but western WA, esp my area, sucks for that kind of accessible fun.

I do know that Auto LSD was the best mode for 0-60 runs. That took half a day of driving around to find a safe, secluded spot.

 

Thanks tonered...
I am also hoping for an Off Road TRD 4x4 to give the full test. The hydraulic brake booster that is only in the Off Road is how A-TRAC and MTS provide the 4-wheel locker simulation.

 

You're welcome!

Very true, but as we have seen in some videos and my own experimentation, the SR / SR5 / Sport / Limited seem to have an upgraded TRAC system also. Still limited by the pressure of the vacuum boost though.

This took some driving around to find, but all modes other than 2Hi default and TCS Off got me up the side of this dock ramp:





I think I posted these in the pre-sticky thread. The rear lifts first, but the front was barely one the ground also. Zero issue getting up over the side with just a bit of throttle above idle.

 

I know I know.
Being in a state where the gypsum stacks are the tallest hills in their entire state doesnt help though, just saying.

BTW Tony, interestingly enough when I was doing the jack tests, the Trac and MTS on auto OR dont activate until you get some throttle in. (So with a couple of wheels jacked up, in gear and engine idling along at 5-10 mph, the system wont fire the brakes for traction control even though 1 wheel is grounded and the other spinning freely. As soon as you give some throttle, the brakes fire. It appears the system is inhibited below a certain throttle application level I assume.)

 

Yes. That is common for traction and stability systems. I think it is a hold-over from MTs, which allows the engine to not stall. This was the factory procedure for doing an MT fluid swap on our old saab where the new lube was incompatible. You had to fill and flush it twice while idling in 1st gear for a few minutes. Well, being the person that I am, I thought that rowing the gear would help the flush. 2nd through 5th at idle, or 1st above ide, fired off the TCS, which I then just turned off.