FEH and extreme cold climates-any issues?
#11
09-27-2009, 05:15 PM
Re: FEH and extreme cold climates-any issues?
This is my experience with driving in the snow on unmaintained roads.
I was traveling to the Crystal Lake Nordic Ski area in Pa. when my GPS unit sent me up a rural road to the location. This road was not plowed, the local snowmobile club existed at the top of the hill where this "rural road" connected to the paved road leading to the ski area. The photo does not show the deeper snow I plowed thru. I use Goodyear Frontza Triple Treads for the 3 winter months as they provide superior traction compared to the stock tires.
I was traveling to the Crystal Lake Nordic Ski area in Pa. when my GPS unit sent me up a rural road to the location. This road was not plowed, the local snowmobile club existed at the top of the hill where this "rural road" connected to the paved road leading to the ski area. The photo does not show the deeper snow I plowed thru. I use Goodyear Frontza Triple Treads for the 3 winter months as they provide superior traction compared to the stock tires.
Last edited by Billyk; 09-27-2009 at 07:37 PM.
#12
09-27-2009, 06:44 PM
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Re: FEH and extreme cold climates-any issues?
"..4Wd is "all time".."
NOT...!!
In order to be "all time" there MUST be some method of allowing "slip" between the front drive and the rear drive. The FEH has no such capability, at least not one that can be used "full-time".
The FEH only engages, normally, the rear drive under moderate to heavy acceleration or heavy engine loads/loading (towing, uphill, etc.). At all other times ONLY the front wheels are driven. During these "other" times should those front wheels, or wheel, develop wheelspin/slip then the rear drive is quickly engaged, the TRAC system starts applying "moderate" braking to the front wheels in order to sustain engine torque to a high level, and the engine is dethrottled.
Ask anyone who wishes to dispute the above to consult the Ford documentation on the operation of the FEH's F/awd system (and the documentation for the Mazda CX-7, Toyota Venza, 2010 Lexus RX350, and the new Porsche C4).
NOT...!!
In order to be "all time" there MUST be some method of allowing "slip" between the front drive and the rear drive. The FEH has no such capability, at least not one that can be used "full-time".
The FEH only engages, normally, the rear drive under moderate to heavy acceleration or heavy engine loads/loading (towing, uphill, etc.). At all other times ONLY the front wheels are driven. During these "other" times should those front wheels, or wheel, develop wheelspin/slip then the rear drive is quickly engaged, the TRAC system starts applying "moderate" braking to the front wheels in order to sustain engine torque to a high level, and the engine is dethrottled.
Ask anyone who wishes to dispute the above to consult the Ford documentation on the operation of the FEH's F/awd system (and the documentation for the Mazda CX-7, Toyota Venza, 2010 Lexus RX350, and the new Porsche C4).
Last edited by wwest; 09-27-2009 at 07:28 PM.
#13
09-27-2009, 07:31 PM
Re: FEH and extreme cold climates-any issues?
To the end user the system is "all time" in that it cannot be disabled (without doing your crazy hack job or otherwise defeating the intended system design).
Quit being a troll!
Quit being a troll!
#14
09-27-2009, 07:36 PM
Re: FEH and extreme cold climates-any issues?
"..4Wd is "all time".."
NOT...!!
In order to be "all time" there MUST be some method of allowing "slip" between the front drive and the rear drive. The FEH has no such capability, at least not one that can be used "full-time".
The FEH only engages, normally, the rear drive under moderate to heavy acceleration or heavy engine loads/loading (towing, uphill, etc.). At all other times ONLY the front wheels are driven. During these "other" times should those front wheels, or wheel, develop wheelspin/slip then the rear drive is quickly engaged, the TRAC system starts applying "moderate" braking to the front wheels in order to sustain engine torque to a high level, and the engine is dethrottled.
Ask anyone who wishes to dispute the above to consult the Ford documentation on the operation of the FEH's (and Mazda CX-7, Toyota Venza, 2010 Lexus RX350, and the new Porsche C4.
NOT...!!
In order to be "all time" there MUST be some method of allowing "slip" between the front drive and the rear drive. The FEH has no such capability, at least not one that can be used "full-time".
The FEH only engages, normally, the rear drive under moderate to heavy acceleration or heavy engine loads/loading (towing, uphill, etc.). At all other times ONLY the front wheels are driven. During these "other" times should those front wheels, or wheel, develop wheelspin/slip then the rear drive is quickly engaged, the TRAC system starts applying "moderate" braking to the front wheels in order to sustain engine torque to a high level, and the engine is dethrottled.
Ask anyone who wishes to dispute the above to consult the Ford documentation on the operation of the FEH's (and Mazda CX-7, Toyota Venza, 2010 Lexus RX350, and the new Porsche C4.
Willard does not have a FEH. The rear driving wheel are engaged almost all of the time and this includes under less than moderate to heavy acceleration. Heck, this feature was "on" almost continously for my steady state highway driving on dry pavement earlier this month. The amount of torque sent to the rear wheels varies and one is often able to "temporarly" change this value via "feathering the gas pedal". The real world and what one intreprets from the Ford Documentation do not match.
#15
09-27-2009, 08:47 PM
Re: FEH and extreme cold climates-any issues?
Here we go again. Willard does not have a FEH. The rear driving wheel are engaged almost all of the time and this includes under less than moderate to heavy acceleration. Heck, this feature was "on" almost continously for my steady state highway driving on dry pavement earlier this month. The amount of torque sent to the rear wheels varies and one is often able to "temporarly" change this value via "feathering the gas pedal". The real world and what one intreprets from the Ford Documentation do not match.
Willard does not have a FEH. The rear driving wheel are engaged almost all of the time and this includes under less than moderate to heavy acceleration. Heck, this feature was "on" almost continously for my steady state highway driving on dry pavement earlier this month. The amount of torque sent to the rear wheels varies and one is often able to "temporarly" change this value via "feathering the gas pedal". The real world and what one intreprets from the Ford Documentation do not match.My SG-II on my '09 FE will show rear wheel leaving a dead stop no matter how lightly I try to touch the throttle.
If your getting rear wheel torque driving at a steady speed on dry pavement, you shouldn't and you have a problem.
There is indeed a way to disable the 4WD system! Pull the fuse for the 4WD module but it will lite the wrench dash icon.
I ran into a issue with the SG-II while trying to monitor another value. The 4WD's module was coming up in the response. Since you have three SG-II's, I'm wondering if your getting bogus readings?
#16
09-28-2009, 09:52 AM
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Re: FEH and extreme cold climates-any issues?
There are "end-users" and then there are "END USERS" that live in areas that REQUIRE them to have intimate knowledge of certain functionality aspects of their vehicles.
#17
09-28-2009, 10:03 AM
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Re: FEH and extreme cold climates-any issues?
The 4WD drive system for both the FE and FEH are same although the programing may be different and might be different for your model year.
My SG-II on my '09 FE will show rear wheel leaving a dead stop no matter how lightly I try to touch the throttle.
The FEH obtains CVT, Continuously Variable Transfer, somewhat linear torque transfer functionality, via the use of PWM, Pulse Width Modulation (duty cycle) of the applied voltage. But it is HIGHLY unlikely that the voltage level applied at any moment directly relates to the level of torque transfer. In my experience it is not at all unusual to have a 50% voltage applied before reaching ANY level of torque coupling using this PWM technique.
So you may be seeing a "keep-a-live" voltage on the SG in preparation for the potential need to engage the rear driveline. In the same way some marques are now applying the brakes ever so lightly if it is raining.
If your getting rear wheel torque driving at a steady speed on dry pavement, you shouldn't and you have a problem.
There is indeed a way to disable the 4WD system! Pull the fuse for the 4WD module but it will lite the wrench dash icon.
I ran into a issue with the SG-II while trying to monitor another value. The 4WD's module was coming up in the response. Since you have three SG-II's, I'm wondering if your getting bogus readings?
My SG-II on my '09 FE will show rear wheel leaving a dead stop no matter how lightly I try to touch the throttle.
The FEH obtains CVT, Continuously Variable Transfer, somewhat linear torque transfer functionality, via the use of PWM, Pulse Width Modulation (duty cycle) of the applied voltage. But it is HIGHLY unlikely that the voltage level applied at any moment directly relates to the level of torque transfer. In my experience it is not at all unusual to have a 50% voltage applied before reaching ANY level of torque coupling using this PWM technique.
So you may be seeing a "keep-a-live" voltage on the SG in preparation for the potential need to engage the rear driveline. In the same way some marques are now applying the brakes ever so lightly if it is raining.
If your getting rear wheel torque driving at a steady speed on dry pavement, you shouldn't and you have a problem.
There is indeed a way to disable the 4WD system! Pull the fuse for the 4WD module but it will lite the wrench dash icon.
I ran into a issue with the SG-II while trying to monitor another value. The 4WD's module was coming up in the response. Since you have three SG-II's, I'm wondering if your getting bogus readings?
Last edited by wwest; 09-28-2009 at 10:13 AM.
#18
09-28-2009, 10:29 AM
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Join Date: Sep 2006
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Re: FEH and extreme cold climates-any issues?
The 4WD drive system for both the FE and FEH are same although the programing may be different and might be different for your model year.
My SG-II on my '09 FE will show rear wheel leaving a dead stop no matter how lightly I try to touch the throttle.
If your getting rear wheel torque driving at a steady speed on dry pavement, you shouldn't and you have a problem.
This statement has the potential for being somewhat missleading.
At least one of the marques using this dual clutch technique, electric clutch controlling a mechanical (hydraulic..??) one, to couple drive torque does convey at least some minor level of torque continuously.
Mazda CX-7, I think.
As a result they had to add an engine coolant line to the PTO to keep it cooled as a result of the stress of having both front and rear drive engaged sligtly even on dry pavement.
There is indeed a way to disable the 4WD system! Pull the fuse for the 4WD module but it will lite the wrench dash icon.
I ran into a issue with the SG-II while trying to monitor another value. The 4WD's module was coming up in the response. Since you have three SG-II's, I'm wondering if your getting bogus readings?
My SG-II on my '09 FE will show rear wheel leaving a dead stop no matter how lightly I try to touch the throttle.
If your getting rear wheel torque driving at a steady speed on dry pavement, you shouldn't and you have a problem.
This statement has the potential for being somewhat missleading.
At least one of the marques using this dual clutch technique, electric clutch controlling a mechanical (hydraulic..??) one, to couple drive torque does convey at least some minor level of torque continuously.
Mazda CX-7, I think.
As a result they had to add an engine coolant line to the PTO to keep it cooled as a result of the stress of having both front and rear drive engaged sligtly even on dry pavement.
There is indeed a way to disable the 4WD system! Pull the fuse for the 4WD module but it will lite the wrench dash icon.
I ran into a issue with the SG-II while trying to monitor another value. The 4WD's module was coming up in the response. Since you have three SG-II's, I'm wondering if your getting bogus readings?
But as was said, if you "feel" torque to the rear on dry, highly tractive, roadbed conditions other than under acceleration(***), then something is definitely amiss.
*** And not even under acceleration at low speeds when turning, especially in a fairly tight radius.
#19
09-28-2009, 10:37 AM
Re: FEH and extreme cold climates-any issues?
#20
09-28-2009, 10:51 AM
Re: FEH and extreme cold climates-any issues?
There is also the matter of "sticktion" when using an electric solenoid "bang-bang" servo-valve in the manner, PWM voltage application to obtain linear "servomotor" functionality. It has been common engineering practice since at least the 1960's to continuously "dither" the movement of the solenoid plunger very slightly using a relatively low frequency AC voltage, in this case probably a pulsating DC voltage. So measurement of a voltage level on the signal line to the rear driveline clutch may, or may not, mean any substantial level of torque is being conveyed.
The SG-II is reading the Ford PID for duty cycle on the ATC unit in the rearend.
That's why also there is a TSB #09-12-11 for 4WD Escape making a "hooting" like noise when leaving a dead stop. Reprograming of the 4WD module is supposed to somewhat "reduce" that noise. If the 4WD wasn't enabled then, there'd be no noise.
I might add that when the fuse is pulled to disable the 4WD module, you can easily feel the difference!
