I thought all hybrids like the FEH had to have traction control, because without it the traction motor can be overspun. I know this is true for the Prius, which has an extremely similar hybrid system.

Traction control can be done by backing off the throttle and/or by using the ABS system to brake any spinning wheels. It may be that prior to 2009, only one of these was fitted, and probably the throttle backoff.

What was not available at all prior to 2009 on the FEH, was stability control.

 

First, "offroad" usually is a misnomer, because in most parts of the world, you can't go two feet without some sort of a prepared road.

I've had the awd FEH long enough to know that it's not bad in "offroading". It's at least the equal of other small awd suv's on rough steep gravel, in snow and on ice.

The predictive awd gives it an edge on many of them that just have slip&grip. The brake-based traction control also helps.

The clearance is good, with the exception of the low chin spoiler and the hanging rear control arms. Still not bad though.

The location of the heavy traction battery gives it a better weight distribution than almost any other small suv.

It falls short of the Suzuki Grand Vitara because the Vitara has a low range and a perfect weight distribution. Similarly, Jeep Patriots and some Jeep Compass' can be optioned with a single low gear. The Patriots with the low gear also come with extra clearance and skid plates.

Where the FEH clearly and greatly falls short of other suv's for "offroading", is that it has no effective engine braking for steep, slow and prolonged descents. Of course, this won't affect those who don't drive in mountains, but I do.

 

You've read too many sales brochures! How can it possibly detect wheel spin before it happens as the sensors are on the wheels? Just think about it.

There was lots of incorrect information out there about this system.

 

For example, when the FEH is at a standstill, and you release the brake and press on the gas, the rear wheels are automatically and immediately engaged even without wheelspin. This is because the computer controlling this knows that the vehicle is in a circumstance where front wheelspin might happen. People with a Scangauge have verified this.

They have also found that the rear wheels are engaged in all sorts of other circumstances even if there is no wheelspin.

So that's why I call it a "predictive" system and why it's one step better than ordinary slip&grip. And the FEH is far from the only and far from the first vehicle to have a system like this.

Yes, the FEH probably also engages the back wheels when the front wheels are detected to be spinning. But if that is so, it is in addition to the predictive system I described.

 

No, there is no TC that I'm aware of.

 

Works the same on a FE, Fusion, etc. and I also have a SG-II. Advertising leads one to believe that the rear only engages with front wheel slippage but that's not so as you have described. Actual interviews with Ford Powertrain Specialists stated that under full throttle take off that "all" power is directed to the rear wheels which isn't true either. I believe they also stated that the system knows front wheel slippage is going to happen before it does and that's why I mentioned it.

The 4WD system is what brought me to this forum. I first used a scope on the 4WD module's output. There is a very long thread here about it where I posted screen captures. CarlD/DesertDog who came up with the SG-II coding for the 4WD modified the parameters after seeing my posts as my SG-II readout was twice what the scope showed.

 

I guess the switch on the dashboard of mine to turn off the traction control must be a fake or some sort of factory joke.

 

The '09 FEH was the first FEH to have TC and many other things. The '09 FEH was the first FEH to have the larger 2.5L engine with broadband heated O2 sensors to handle E10 without a big hit to MPG. IMHO, the '09 FEH was the most efficient FEH made.

Steve knows what he's talking about also!

Gary

 

That clears up a few things. But to explore it farther...

I know the earlier Prius' had very aggressive traction control that prevented all wheelspin so that one of the electric motors would not be damaged by "overspeed" or something like that, caused by unlimited wheelspin. I believe this feature resulted in complaints of Prius drivers being stranded in situations where a bit of wheelspin would have allowed them to proceed. So somewhere around 2008, the Prius was modified to allow a little wheelspin.

Since the FEH has such a similar hybrid setup, I don't see why this would not apply to it also. Alternatively, I understand that this overspin condition is what limits a hybrid's top speed in ev mode. The electric motor in question would not see a difference between being overspeed caused by wheelspin or excessive speed in ev.

I have been able to proceed up a snowed-in hill with wheels spinning slowly and with TC engaged. I have also ground to a stop in similar conditions with TC engaged, but in ev mode. It just slowed and slowed and then stopped with no wheelspin. I have yet to figure out what the difference was between the two situations. I didn't try taking a little run at it, or shutting off the TC since I didn't need to go up the hill.

 

The Prius has a different electronic control system. The FEH eCVT is protected from over-spin of MG2 by starting the engine.

Every Escape was fitted with Roll Stability Control (RSC) in '09, including the FEH. This system works with ABS and traction control. I never had a reason to mess with my '09 FWD RSC because I have no hills or snow here in Jupiter FL.

Gary