I'm going to purchase an H3, and need some info about TCS (Traction Control System). Before I ask my questions, I first need to explain why:

In the Jeep/Do-It-Yourself world, there is agear-driven, limited slip differential that you can install either front, rear or both. It's called the Detroit TruTrac. It's not a full locker, but darned close and far better than any other form of limited slip differential on the market. It's considered a "locker without the problems of a locker". It works by producing extremely strong limited slip when needed, but oddly, will not do so when one of the wheels is freely spinning. It only grabs when there is at least some resistance on the slipping wheel, at which point engine power is then transferred to the non-slipping wheel. The driver must feather the brake pedalto add resistance to a free-spinning wheel.Otherwise, the whole thing is often so seemless that the vehicle keeps moving without missing a beat. It's actually quite brilliant and works very well, aside from having to manage the brake pedal.

Question #1: I know that the H3 TCS is a system of automatically applying brake pressureto a free-spinning wheel. It seems to me that this would be because the H3 is using something similar toa Detroit TruTrac differential up front. Am I correct in this assumption?

Question #2: Is this TCS functionality found in the rear diffif you don't get the off-road package with the locking rear differential?

Knowing these things is very important to me because it dictates what I can and can't do with this vehicle.

 

yes on both questions.

the Traction control will sense a wheel is spining and put full power to the wheel that is not spinning. It works on all 4 corners. So even without a locker the Traction control will do almost as good of a job. By applying the brake manually you will in effect turn off traction control becasue you will be controlling where the power goes.

 

Excellent, thank you. And now for the inevitable 3rd Question:

Does the locking rear diff option also include TCS functionality when not locked or is it just standard open diff?I couldn't see how the rear diff could be both, as they are two different technologies altogether, but I thought I'd ask anyway.

 

I do believe it has both, the traction control is made for on road situations as well as off road situations so GM wouldn't take it out on an adventure model h3. Bieng that the rear locker can only be activated in 4 low my guess is it electronically shuts off in 4 low so that the locker can be activated. Not real sure....great question.

 

I much appreciate your knowledge and honesty. What I think I'll do is call up the dealership and see if I can get a tech on the line to answer that question and then post what I find so everyone else will have the info as well.

:-)

 

ok, I've been talking to people about this and from what I can gather the traction control system is not a locking diff type system, like the Detroit, rather it is electronic and work with the engine management system and the ABS system to limit the power to the spinning wheel and to deliver it to the wheel with traction.

Took this from a magazine artical:

The H3 features an anti-lock braking system that uses Dynamic Rear Proportioning to help control rear braking in a panic stop situation.
The H3's traction control system works in conjunction with the engine controls and brake system to provide maximum traction with minimum wheel spin, even in the worst of conditions.

 

Ok, here's the final word from the dealership:

The 4-channel ABS brakes are used for multiple functions on the H3:

1. They are used as regular anti-lock brakes for normal stopping.

2. They are used as part of the StabiliTrak system for automatic rapid, proportioned braking to different wheels as a sort of "parachute system" in the event of understeer, oversteer or swerving sharply to avoid an obstacle.

3. They are used as part of the Dynamic Rear Brake Proportioning System to balance brake pressure between front and rear so the vehicle doesn't nose dive on hard breaking.

4. And as we suspected, they are indeed used to provide resistance to any free-spinning wheel so engine power can be diverted to non-slipping wheels via the TruTrac-style system I mentioned earlier.

Further:

Both locked and non-locked H3 models perform identically when 3 out of 4 wheels have broken loose. The vehicle will work harder to move with only one wheel having any traction, but will still move. The web site states that, with only one wheel having traction, the vehicle will still be able to climb a 10% grade.

This answers my third question.

I was directly told that it doesn't matter if you have the off-road package (rear locker) or not, TCS works the same way on both models, all 4 wheels. So it appears they have indeed found some way to merge limited slip functionality into that rear locking diff when it's not locked. I'm impressed as all hell. Though maybe not as heavy duty (lots of little moving parts), this is actually far more advanced technology that what's even under an H1.

In a nutshell: Damn this thing is cool.