A-trac in 4lo on all 2016 4x4 Models Non Trd Offroad

Ok this document is now officially a group effort, with 3 people providing direct data. So with that many cooks there will always be some levels of disagreement, but I want to try and keep 'everybody happy', and this thing can be much much better, so keep giving suggestions.

What do people think of the format. I am very much torn about using my own terms for 'differential conditions' etc, but with crappy toyota terms, I don't rightfully know what else to do.

Doggman, good catch on 4Hi. That actually directly contradicted my own data I think... Your data is incorporated on the summary table, but why don't you go fill out one of the second tables for OR manual with a full set of the dash lights.


For 3rd gen 4WD SR/Limited/Sport, I need more double checking. What is the diff status for short press and long press of the VSC-off in 4Lo?

Please keep double checking this data people, there are probably more errors.

Updating figures.
[Edit: latest figures
https://www.tacomaworld.com/threads...non-trd-offroad.437814/page-22#post-16989593]

 

No data yet.
I would love data, and a full population of the dash lights would be great. (plus a garage jack test even better yet)

 

I'd say the only thing needing to be changed is 4HI TRAC-OFF(quick push) does have throttle intervention, if you start sliding/getting pushed around

 

Do you think the throttle intervention is for traction control or for stability, or both. (I know this is all intermixed, but I think there is throttle intervention caused only by tire slippage (without any excessive yaw detection), there is throttle intervention when excessive yaw is encountered, and probably both). I am not sure yet, and havent really tried testing yet when these might be, or if we care.

Wonder if we need to separate throttle intervention into two parts....

 

Here is latest spreadsheet, please populate a new section with any new data. Anybody providing data, please try not to guess with anything. (I think Bad data is worse than no data.) Which is why we are correcting my mistakes right now...

 

From my findings/driving in TRAC-OFF mode there is only throttle intervention when excessive yaw is encountered. I use TRAC-OFF when off-roading snowy conditions on ice, that way I can still spin the wheels without any throttle intervention to power through a snow drift but if I hit an ice patch coming out of the drift the truck will help correct before getting to out of hand.

It is very apparent that VSC is still on when following a rutted track through a snow drift and getting bounced around as you really aren't steering the truck more just going where the track is. The VSC system and slip indicator light is constantly going off.

 

If someone doesn't step up before then, I can do some testing next weekend. I'm going to be traveling this weekend and next week.

 

Thanks...

As for the nice chart made by BigWhiteTRD, above, I am having difficulty (with Toyota, perhaps) in that 4WD-HIGH, the charts shows no difference between TRAC OFF MODE (TRAC-OFF, VSC) and VSC OFF MODE (TRAC-OFF, VSC-OFF)??? Both are listed "fully open differentials". This contradicts the 2WD, AUTO LSD MODE, which is also technically a TRAC OFF MODE that says (correctly): Brake simulated limited slip.

The TRACtion control without engine regulation (called TRAC OFF in H4 since 2012) was a really big change over H4 in my 2005 Tacoma, in that I could cross deep sand and climb grades easily that required deflating tires before.

 

Based on what I have seen, I have noticed this driving on slippery roads as well. No engine regulation (I am able to rev the engine up a little more to power thru higher drifts similar to what @Cold_Toad experienced.

 

I think the title of this thread is keeping many 4x4 OR drivers from chiming in---since we have opened up the discussion to all models, can I resuggest starting a new thread and linking to this? I know that was mentioned a few pages ago but just wanted to bring that back up

 

Very nice job! This will help a lot of people and get rid of a ton of disinformation. Thanks for your time man.

 

I think you are correct, I haven’t confirmed with a 4wd drive donut , yet. I was referring to the straight line traction part.

 

I agree and I have not figured it out yet fully. Need to more experiment with throttle regulation maybe.
I will tell you dash lights in 4Hi for my 2017 OffRoad automatic, which might explain it better to you than me..


In 4Hi, with no buttons pressed , no lights, get brake LSD when jacking both LH wheels up
In 4Hi, with quick press of VSC-off, I get "TRAC-Off" light, and when jacking both LH wheels up, there is no notable brake LSD
In 4HI, with long press of VSC-off, I 'TRAC-Off" and "VSC-OFF" lights, there is no notable brake LSD

SO maybe no press has LSD, short press has no LSD but throttle regulation, and long press is no LSD and no throttle regulation....
not sure..

BTW, THis may be an area where the trim levels are different, and that is causing more confusion too. Please keep helping and asking questions, because I think we are all learning together here.

 

It is for sure an On/Off switch. When you press it, it stays depressed and when you press it again it releases. It's like the top of a ball point pen.

I believe this is the answer to 4HI and lines up perfectly with the verbiage that Toyota has put out.

I went back and read some of @David K 's original threads for the 2nd gen and they seem to have concluded something different in this mode. They seem to have thought that TRAC OFF in 4HI was basically ALSD but in 4HI. A stronger version of limited slip with no engine regulation. I question this because it doesn't line up with what Toyota has said but it could have been different, I don't know. I think that ALSD is strictly a 2wd feature and you do not get that functionality in 4HI.

The way I see it in 4HI you have 3 modes:

• Default TRAC and VSC both on. In this mode the truck will do everything it can to prevent you from losing traction. It's going to cut engine power, apply brakes, etc in all cases it deems necessary including burnouts, donuts, slippery surfaces, lifting a wheel etc
• TRAC Off but VSC still on. In this mode the truck will no longer intervene unless you have triggered VSC which can cut engine and apply brakes. So this is like half and half. VSC will still kick in when shit gets really out of control but if you are just losing traction while crawling or doing burnouts it will not do anything. The reason this mode is valuable is because it allows you to power through stuff. Toyota even says this explicitly in the manual. You go to this mode when you need TRAC to stop cutting engine power.
• Both off. This mode is obvious. You're on your own.

 

My explanation for this is that the engine regulation in TRAC was making those difficult and when you switched to TRAC Off you were able to power through those obstacles. It wasn't because of an ALSD like feature kicking in during 4HI TRAC OFF. Just my thoughts. Could totally be wrong but it seems like if there was LSD like functionality in 4HI these guys would have seen it work when they put 2 wheels (1F 1R) on jacks and tried it.

 

Well written and on point for 4Hi I think. It doesnt match with previous Gens, but I think it's right.

So now need to verify (which maybe have enough proof already).

Secondly, once proven, how do we document.

 

The first part is exactly the same as my truck functions for dash lights and buttons pressed. The conclusion should read as follows.

In a SR

no press= limmited slip diff traction front and rear with vsc active
Short press= no limmited slip diff traction front or rear with vsc active
Long press= no limmited slip diff traction front or rear with no vsc active

For the short press, vsc will activate on when excessive yaw detected. As Cold_Toad posted.

 

You know, the more I think whole thing the more pissed off I get. Some engineers at Toyota understands all of this 100%
Would it really have been so hard to document all this better in the like 1000 page manual?

 

I almost would bet this is due to the legal department. It they make it confusing to the point that people won't press the buttons then they will leave the truck in the safest mode for driving.

 

@PB FAB, @Doggman, thank you for that help with 4Hi.
Spot on I think as I go back over my data.

So how do we document? I was trying to keep the Toyota descriptions of the modes below the table, but I am think that it is time to just trash them all together and rewrite them.
Or do we make differential and throttle columns for Traction control and another set for Stability Control maybe?
Or do both of the above?

Or am I going too far down the rabbit hole, and 90% of the people reading it aren't going in far enough to care?

What does everybody think?