Take it from Carl on this issue. I do not have Ford Motor Company equipment to dispute this. This is a question for the experts to debate.

 

In BillyK's post somewhere above, he stated that he gets a 4WD value while on the highway on a dry sunny day. It's not a question if the value is a good approximation but why is he getting a value at all under those driving conditions. The 4WD/AWD system shouldn't be enabled at all.

Looks like you spent lots of time trying to figuring this out on a FWD. It would be difficult to force 4WD operation other than maybe lifting the front end and one rear wheel but that would probably send 100% to the rear. The other is a full throttle start from a stop which also is supposed to send 100% torque to the rear wheels. No real way to force anything under 100%.

 

Don't need to be a expert, just think about what/when your SG-II is showing rear wheel torque. On dry pavement????

 

Very Interesting Discussion. Perhaps the mystery here does have more to do with the Hybrid 4WD/AWD. Since the FEH/MMH hybrid system uses the electric engine for extra torque in situations that require more torque than the Atkinson cycle combustion engine can provide (Atkinson cyle has significantly reduced torque capability - as compared to same 4cyl. engine in a gas only Escape) Maybe the Hybrid designers determined to send the electric engine torque to the rear wheels (or much of it) when it was called for - as in accelerating on a dry pavement highway? Just speculating here - but that seems to make sense to me and explain why it was happening this way - versus a non hybrid escape only sending torque to rear wheels when there is front wheel slippage?

 

I have the 4WD version of the FEH and I also found it somwhat surprising that I have power to the rear wheels on dry pavement. For some reason I assumed that the rear wheels would only get power when there was need, ie traction issues with the front wheels. Using the scanguage to monitor it's very apparent that the rear wheels get power. From a dead stop the scangauge shows that the rear wheels get approx 64% it then drops to the mid 30's relatively quickly then mid 20's and seems to skip from there to zero. This is on dry pavement. Once moving, I can accelerate at a moderate pace and not engage rear wheels but from a dead stop I cannot get going without them. If anyone has anything they'd like to try in order to clarify anything let me know and I'll do the best I can.

Mitch

 

Where's the data that the Hybrid 4WD/AWD is different "on demand" system. I think that the link I provided above was from a interview with somebody from Ford and nothing is mentioned.

Even to a laymen, where's the logic to engage the rear wheels when your crusing down the highway on a dry sunny day? Not sure about the Hybrid transmission but on mine, any substained speed around 45MPH goes into overdrive or less power needed. Where's the demand for rear wheel torque?

 

OK, you're right - the hybrid differences can be confusing, so let me try to explain it a little differently. Power to the wheels in a Hybrid IS different that in a convential non Hybrid. For example - the transmission in the Escape/Mariner Hybrid is an eCVT - not a 4 or 6 speed transmission. Interestingly enough, the eCVT in the FEH/MMH does NOT have a reverse gear. So, to back up in a FEH/MMH, the electic moter is driving the wheels directly in reverse. Since the electric motor also provides torque when needed - especially needed from dead stop until approx. 25+ MPH, I am speculating that maybe the electric motor torque is being sent directly to the rear wheels in an the AWD/4WD Escape/Mariner Hybrid, and hence is providing the readings that those monitoring with the scangauge are seeing. I think this could be true - but again speculating. I also think that as the ICE engine delivers power to the wheels through the eCVT AND when the front wheels detect slipage, then power is diverted to the rear wheels as happens in a conventional AWD/4WD Escape. I hope this explanation helps - and based on my knowledge and a full year of experience with the 2008 MMH AWD - this is what I think is happening. Again it is my speculation.

 

Where are you getting your knowledge from, a book, etc. How do you know the the rear wheels get torque till 25+MPH, a SG-II?

If you have normally FWD, why would you need rear wheel torque from a dead stop, where's the need? Compared to a Hybrid FWD only, what's the improvement? 4WD/AWD is all about traction and control under abnormal driving conditions, so where's the need with a Hybrid?

 

There is a sensor at the "gas" pedal (previous references) that inputs into this equation. How one presses the gas pedal will influence the if and how much torque is being sent to the rear wheels to minimize torque steer. This is true in electric mode when the ICE is off. This information can explain why torque is sent to the on sunny and dry days.

When can a owner of a non-hybrid Escape display their scanguage findings on this subject.

 

Well, the throttle on the '09s are drive by wire, not sure when they started that but the throttle position sensor(TPS) used with the older linkage system has been around since the eighties. The TPS is one of many PCM inputs. I'm pretty sure that the TPS is still used today without a direct mechanical connection.

That doesn't explain it.

I've been tempted to get a SG-II!!