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

 

That's good to know. Are you still able to steer without power? I would imagine if it's a regular mechanical power steering system it's just more difficult to turn the wheel, but if it's one of those new electronic steering deals it's probably not possible at all.

 

I'm pretty sure even in the electric ones you can still steer with the system dead... the electric just performs an assist as it does in a hydraulic system. The turning is still rack and pinion or whatever.

 

Lawyers wont let them do a steer by wire. Remember the Audi 5000and 60 minutes,( unintended accelleration) and it was even a real problem. A test for this is can you steer the car with the key off afterf it has sat for a while.

 

You can still steer mechanically, by muscle alone, if the car is not "started" or if the power steering ever malfunctions. Same with the power brakes. I'm sure there is some mandate to always have a minimum amount of control in case of electrical failure.

 

"Posted by Some"? I'm the only one that posted this information and have been doing Key-Off FAS for 5 months now. The only time I've had the feel of no power steering is when I slowly returned the key back to the run position at a very slow speed. In addition, I posted that if your moving, the electric power steering is designed to reduce the amount of assist so you can get a better feel of the road for vehicle control (SAFETY REASONS!). This has always been argued by me that there is no safely issue with loss of power steering.

If anyone is dumb enough to FUMBLE and remove the key, they have bigger problems than no power steering. What about a locked steering wheel?

The fact is, I've never notice weather or not the power assisted steering is on or off over 20 mph. A FAS normally never last over 12 seconds unless you plan to come to a long stop. Most FAS are between 8-10 seconds.I turn the key back to the run position right away to keep the SG and navi mpg counts straight as possible. I think the electric power steering has alway remained on in the past 5 months, except for a few test I ran with the key off longer at a slow speed.

This subject is turning out the same as when I introduced neutral coasting. All kinds of scare post of how it would damage the eCVT or how it didn't help over coasting in "D" were posted. This time next year FAS will be the talk of this and every FEH/MMH board. Guess what, I have 5 months of experience and a jump on everyone using FAS in the FEH. Don't say I didn't try to let everyone know about it here 4 months ago.

As you learn when to use FAS, your mileage will get much better. What I've learned is to drive much faster while maintaining over 45mpg tanks.

Good Luck

GaryG

 

For this reason alone (if no other reason), I have always thought this is a totally ridiculous idea.

~John

 

Gary,

I haven't looked at the gal/hour fuel consumption of an idling FEH, but in my previous car it was about a half gallon per hour. If I divide that out to determine how much fuel you save in a 10 second FAS, it's .00138 gallons. Granted, at highway speeds the FEH isn't idling, so the fuel savings is surely more. But even if it's four times more it's still only .005 gallons per FAS. If you FAS twenty times per tank it's .1 gallons. For my recent average MPG that would give me a boost of about .2 MPG overall.

So when you say that FAS will make your MPG much better, you would probably need to FAS more often or for longer durations than what I've figured, right?

 

I've found that FAS is really not helpful 99% of the time.
The only time I really do it is when I'm waiting in line for a bank teller on a cold day. In these cases, you should all do it, since you are not moving.

Without FAS at all, I can routinely get 55 MPG around town.
I'm very happy with this.

There have been a few times when I was tempted to do FAS at highway speeds when I am going down a long mountain grade. But then I learned the the engine MUST spin above 40 MPH, even in 'neutral'. Then, in a stroke of genius, I'll admit fueled by GaryG's question about fuel cut ability, I experimented on downgrades at highway speeds, and learned how to get the engine to go 'fuel cut' downhill, at any speed, in D or L 'gear'. I found out how to do this on my own, but Gary's question got me looking into it. So I can honestly thank him for pointing me in that direction.

So for me, at speeds under 40 MPH, I don't need FAS to get 55 MPG.
Over the highway, I could use FAS to my advantage, but will never do it since I feel the risk out-weighs the potential gain. Now, with fuel cut mode, I don't need FAS at highway speeds anyway.

To get the engine to cut all fuel ( and still spin ) at speeds over 40, shift to L to get the engine to "rev up". Once the engine revs above normal, all fuel is cut, and the MG1 is spinning the engine with power from the wheels via MG2. You can then shift back to drive, and the RPM will decrease, and the regen will decrease, and your engine will still burn zero fuel while coasting downhill. Even at 75 MPH.

Enjoy! Hope that helps all the owners out there!
-John

 

Relax John, you cannot remove the key in any gear but "PARK". I was just waiting for someone to catch on to what GPSman pointed out about fumbling the key.

Brady, I just checked the time while FAS and it's much longer in the FEH. I took the ten seconds from posters on CleanMPG, but the FEH can coast much longer because of the eCVT disengagement from the wheels. It is true that FAS is something you get better and better at, but this is where people like Wayne Gerdes can push 180mpg out of an Honda Insight and over 120mpg out of a Prius. Now that I know how to FAS the FEH, my mileage will always be better. All these techniques I use have to be used at the right time and situations. I'm getting better everyday at FAS and I assure you it gives me a big advantage over someone not using FAS. Of course I use EV more, but a combination of both is better to have knowledge in.

GaryG