FAS and New power steering info
#21
08-01-2007, 10:58 AM
Join Date: Mar 2005
Location: All over the Central U.S.
Posts: 3,616
Re: FAS and New power steering info
Okay, hopefully this will put things to rest.
I have 100% proof that both the traction motor and generator motor continue to spin at the same speed as wheel speed when in Neutral.
I now have a CAN Bus scanner that will show Motor RPM.
It's really just using the full potential of the ScanGauge.
It's not user friendly, so I'll just give you the short version.
Traction Motor Speed = 128 RPM per MPH
Generator Speed = -156 RPM per MPH ( EV mode )
Gear ratio between the two: 1:1.218750
Measurements done in EV mode, so there is no ICE speed.
Done when coasting in Neutral, down a 1%-2% slope.
1 MPH TM 128 RPM GM 156 RPM ( reverse direction )
5 MPH TM 640 RPM GM 780 RPM
10 MPH TM 1280 RPM GM 1560 RPM
15 MPH TM 1920 RPM GM 2340 RPM
30 MPH TM 3840 RPM GM 4680 RPM
39 MPH TM 4992 RPM GM 6084 RPM
45 MPH TM 5750 RPM GM ~2400 RPM ICE ON
43 MPH TM 5504 RPM GM 6708 RPM measured during a FAS in Neutral
Yes folks, it is true what I have been saying for 2 years now.
There is not a physical disconnect when you shift to neutral.
In Drive and in Neutral, my RPM numbers are always the same.
Both motors always have a RPM relative to wheel speed.
Coasting in Neutral, both motors always rotate based on wheel speed.
Even after a FAS, both motors rotate based on wheel speed!
Anytime the CAN bus is on, the electronics have the wheels attached to the eCVT. When the key is totally off, the CAN bus is off, and I cannot measure RPM's.
But I am 100% positive the motors spin when you are coasting down a hill in Neutral, even if the car is not "started" after a Forced Auto Stop ( no green car icon ).
Before today, any posts about a neutral disconnect were THEORIES.
THIS IS FACT.
Having opposing theories is good.
It caused me to go to great lengths to prove mine was correct.
However, any future claims that neutral disconnects anything other than electrical power will be considered denial of the truth!!
If anyone lives in the North Denver area and would like to see this in person, I will be happy to show this to you in either your car or mine.
-John
P.S. If you want the long version, send me a PM!
I have 100% proof that both the traction motor and generator motor continue to spin at the same speed as wheel speed when in Neutral.
I now have a CAN Bus scanner that will show Motor RPM.
It's really just using the full potential of the ScanGauge.
It's not user friendly, so I'll just give you the short version.
Traction Motor Speed = 128 RPM per MPH
Generator Speed = -156 RPM per MPH ( EV mode )
Gear ratio between the two: 1:1.218750
Measurements done in EV mode, so there is no ICE speed.
Done when coasting in Neutral, down a 1%-2% slope.
1 MPH TM 128 RPM GM 156 RPM ( reverse direction )
5 MPH TM 640 RPM GM 780 RPM
10 MPH TM 1280 RPM GM 1560 RPM
15 MPH TM 1920 RPM GM 2340 RPM
30 MPH TM 3840 RPM GM 4680 RPM
39 MPH TM 4992 RPM GM 6084 RPM
45 MPH TM 5750 RPM GM ~2400 RPM ICE ON
43 MPH TM 5504 RPM GM 6708 RPM measured during a FAS in Neutral
Yes folks, it is true what I have been saying for 2 years now.
There is not a physical disconnect when you shift to neutral.
In Drive and in Neutral, my RPM numbers are always the same.
Both motors always have a RPM relative to wheel speed.
Coasting in Neutral, both motors always rotate based on wheel speed.
Even after a FAS, both motors rotate based on wheel speed!
Anytime the CAN bus is on, the electronics have the wheels attached to the eCVT. When the key is totally off, the CAN bus is off, and I cannot measure RPM's.
But I am 100% positive the motors spin when you are coasting down a hill in Neutral, even if the car is not "started" after a Forced Auto Stop ( no green car icon ).
Before today, any posts about a neutral disconnect were THEORIES.
THIS IS FACT.
Having opposing theories is good.
It caused me to go to great lengths to prove mine was correct.
However, any future claims that neutral disconnects anything other than electrical power will be considered denial of the truth!!
If anyone lives in the North Denver area and would like to see this in person, I will be happy to show this to you in either your car or mine.
-John
P.S. If you want the long version, send me a PM!
Last edited by gpsman1; 08-01-2007 at 09:16 PM. Reason: P.S.
#22
08-01-2007, 06:08 PM
Re: FAS and New power steering info
Have you ever been at home and had the power flicker? Have you seen the lights dim or flicker, and come right back on? You would for sure take notice of this event. Sometimes, this will turn off your TV or reboot your computer if you had it on at the time. Sometimes though, if the flicker is quick enough, just for half a second or less, you'll still notice the lights, but your TV will stay on, and your computer will continue to run unaffected. This is because there is a slight buffer time, or capacitance in most modern electronics.
It has been posted by some, that you can perform a FAS ( forced auto stop ) in the Ford Escape Hybrid, and continue on your way safely, with power steering. It has been posted by some, that you loose power steering with a key off maneuver while in motion. Which is it?
Turns out, the power steering has a bit of buffer time. The computer, or the part of the computer that controls the power steering has a bit of latency. If, and only IF you turn the key off and then back on to run in 2 seconds or less, will the power steering stay "on". If you take your time, or fumble the keys, or get distracted ( actually paying attention to your driving, perhaps? ) and take 3 seconds or more to cycle the key back to run, your power steering will NOT work after a FAS! And you can't get it back on until you start the engine.
I find it very interesting that the computer, or the part of the computer that runs the ICE does not share this same latency. Thus a very quick turn of the key off then back to run will shut down the engine, but not the power steering. This is similar to how a very quick power flicker will not shut down your home computer. Sometimes.
So can you drive after a FAS with power steering? Yes.
Can you rely on it to always work? NO!
Can you have power steering without starting the engine at least once, such as pushing it out of a garage? NO! The engine must have been started once to "activate" the power steering.
Hope this clears up some mis-understanding on this matter.
As far as I can tell, power brakes work all the time, even when pushing the car out of the garage, as just opening the door pressurizes the brake fluid. I used to have a manual garage door, since my power door was broken. I would push the FEH out of my garage and a few feet down my sloped driveway, before getting out and manually closing the garage door. I did this to save gas. I did this without ever starting the car, and power brakes always worked.
Hope you all find this helpful.
-John
It has been posted by some, that you can perform a FAS ( forced auto stop ) in the Ford Escape Hybrid, and continue on your way safely, with power steering. It has been posted by some, that you loose power steering with a key off maneuver while in motion. Which is it?
Turns out, the power steering has a bit of buffer time. The computer, or the part of the computer that controls the power steering has a bit of latency. If, and only IF you turn the key off and then back on to run in 2 seconds or less, will the power steering stay "on". If you take your time, or fumble the keys, or get distracted ( actually paying attention to your driving, perhaps? ) and take 3 seconds or more to cycle the key back to run, your power steering will NOT work after a FAS! And you can't get it back on until you start the engine.
I find it very interesting that the computer, or the part of the computer that runs the ICE does not share this same latency. Thus a very quick turn of the key off then back to run will shut down the engine, but not the power steering. This is similar to how a very quick power flicker will not shut down your home computer. Sometimes.
So can you drive after a FAS with power steering? Yes.
Can you rely on it to always work? NO!
Can you have power steering without starting the engine at least once, such as pushing it out of a garage? NO! The engine must have been started once to "activate" the power steering.
Hope this clears up some mis-understanding on this matter.
As far as I can tell, power brakes work all the time, even when pushing the car out of the garage, as just opening the door pressurizes the brake fluid. I used to have a manual garage door, since my power door was broken. I would push the FEH out of my garage and a few feet down my sloped driveway, before getting out and manually closing the garage door. I did this to save gas. I did this without ever starting the car, and power brakes always worked.
Hope you all find this helpful.
-John
GaryG
#23
08-02-2007, 08:26 PM
Re: FAS and New power steering info
~John
#24
08-03-2007, 01:56 AM
Join Date: Mar 2005
Location: All over the Central U.S.
Posts: 3,616
Re: FAS and New power steering info
"Maybe I'm misunderstanding what you're saying, but if that's true why will an FEH coast farther in nuetral than it will in drive??"
Actually, the whole point is it does not.
Normally, when you take your foot totally off the gas pedal, there is a slight amount of Regenerative braking intentionally programmed to make the car feel like a traditional car that will have engine braking effect.
Truth be told, take away the intentional regen, and you DO coast exactly the same distance in Drive as "pretend neutral".
Neutral "pretend gear" selection only cancels all electrical power in or out of the motors.
You can also cancel out all regen by pressing the gas pedal 1mm or 2mm in drive. This will not add power to the wheels, but it will cancel all regen.
Try it and report back.
If you have the Nav screen, try to get zero arrows on the energy screen.
If you don't, then it may just take extra practice.
There is no mechanical difference as far as the transmission is concerned, however, most people ( myself incl ) think using your hand to move the shifter to cancel regen is easier than using your foot and trying to get exactly 2mm.
However the foot trick is handy, like when you have one hand on the wheel, and the other hand on an ice cream cone... you can still cancel regen and get a "neutral" coast.
-John
Actually, the whole point is it does not.
Normally, when you take your foot totally off the gas pedal, there is a slight amount of Regenerative braking intentionally programmed to make the car feel like a traditional car that will have engine braking effect.
Truth be told, take away the intentional regen, and you DO coast exactly the same distance in Drive as "pretend neutral".
Neutral "pretend gear" selection only cancels all electrical power in or out of the motors.
You can also cancel out all regen by pressing the gas pedal 1mm or 2mm in drive. This will not add power to the wheels, but it will cancel all regen.
Try it and report back.
If you have the Nav screen, try to get zero arrows on the energy screen.
If you don't, then it may just take extra practice.
There is no mechanical difference as far as the transmission is concerned, however, most people ( myself incl ) think using your hand to move the shifter to cancel regen is easier than using your foot and trying to get exactly 2mm.
However the foot trick is handy, like when you have one hand on the wheel, and the other hand on an ice cream cone... you can still cancel regen and get a "neutral" coast.
-John
Last edited by gpsman1; 08-03-2007 at 02:00 AM. Reason: spelling
#25
08-03-2007, 06:32 AM
Re: FAS and New power steering info
Yea, you're right I agree with that, but it is so much eaasier to just pop it into neutral than to give it that "perfect light touch" on the gas pedal to negate that slight regen..........
~John
#26
08-03-2007, 07:59 AM
Re: FAS and New power steering info
Your data have not proven that there is no mechanical disconnect in the FEH. It shows, however, that if it is there, it is not commanded during any normal driving conditions, and not by merely putting the gear selector in neutral. However, since failure of a physical disconnect would be catastrophic, and there is no mention of a DTC related to its failure that I can find, that would sure seem to indicate that it is not there.
Last edited by DesertDog; 08-04-2007 at 09:22 AM.
#27
08-03-2007, 08:15 AM
Re: FAS and New power steering info
GaryG
#28
08-03-2007, 10:35 AM
Join Date: Mar 2005
Location: All over the Central U.S.
Posts: 3,616
Re: FAS and New power steering info
DesertDog, let me re-phrase then:
"No disconnect happens when you shift to "neutral" when in motion."
A disconnect does not happen when you shift to "neutral" even with the key off, when in motion.
Maybe a required condition is you need to be at a dead stop for it to occur?
"No disconnect happens when you shift to "neutral" when in motion."
A disconnect does not happen when you shift to "neutral" even with the key off, when in motion.
Maybe a required condition is you need to be at a dead stop for it to occur?
#29
08-03-2007, 11:02 AM
Re: FAS and New power steering info
I guess I wasn't clear, either. There may in fact be NO physical disconnect actually implemented in the FEH, but the neutral towing makes me think there was. The proof of the pudding is in the eating, so I guess one of us will have to dis-assemble an FEH and take some pictures..................
DesertDog, let me re-phrase then:
"No disconnect happens when you shift to "neutral" when in motion."
A disconnect does not happen when you shift to "neutral" even with the key off, when in motion.
Maybe a required condition is you need to be at a dead stop for it to occur?
"No disconnect happens when you shift to "neutral" when in motion."
A disconnect does not happen when you shift to "neutral" even with the key off, when in motion.
Maybe a required condition is you need to be at a dead stop for it to occur?
-J
