Hi, everyone--

My 2007 AWD FEH has 1550 miles on it; I've had it for about 8 weeks. In that time I've had it serviced twice because the brake light and an alarm came on, along with a "service braking system" message.

Both times they found a ground wire that was not properly attached. (They were two different wires.)

Interestingly, since the first repair, my mpg has dropped significantly. (This is NOT associated with corresponding drops in temperature or changes in driving habits.) Before the repair, the tach would drop to EV the second I took my foot off the accelerator, and the display would tell me that the HV battery was being recharged. Now the tach drops to EV only when I actually brake. It does appear from the display that the battery is being recharged when I take my foot off the accelerator, though the ICE appears to still be running (though not powering anything).

In addition, I have a little gauge that supposedly tells me the battery status--the two poles are marked "charge" and "assist." The needle hardly moves from the center position. I can't decide if that means that the system is not working correctly, or if the gauge just isn't that useful.

Has anyone else had this ground wire problem? Should the needle on that battery gauge actually be moving? Is there some way to tell if the HV battery is charging properly or not?

Thanks!

Kay

 

Ordinarily, I'd be one of the people saying "the weather is colder....etc" HOWEVER.... I've got to say that in my '06 that Assist/Charge guage moves more than just a little after the vehicle has been running a couple of minutes. On hard acceleration or long breaking runs where I'm going pretty fast it gets most of the way toward the end for a second or two. If you don't see that... I think there is still something going on....

 

Hi Kay

It sound like the ground wire was causing your FEH to go EV too easy and not like most of our vehicle. Connecting the ground wires could have made your FEH to operate normal. If you were going EV as soon as you let off the gas pedal, this could very well give you much better MPG. The fact that you don't go EV more now may be why you have a decrease in MPG. I kinda wish I knew which ground was disconnected so I wouldn't have to do all the tricks to go EV myself. It almost sounds like the disconected ground wire put you in the "L" (low gear) mode which will almost do the same thing.

My recommendation is to try driving in "L" or shifting to "L" when you are going to let off the gas pedal, and check to see if your FEH reacts like it did with the ground wire removed. You should be going into EV more, and the charge needle should move to the charge area further than it does in "D" (drive). Also, you should be seeing the charge needle swing to charge when you apply the brakes. BTW, there is no low gear in our FEH, the traction motor/generator is slowing the vehicle down and recharging the HV battery when you let off the gas pedal. You can drive as fast as you want in "L" and shift at any speed to low from drive or neutral, or shift from "L" to "D" or to "N" (neutral).

GaryG

 

Thank you, Tim and Gary, for your quick responses.

I have purposely looked at the gauge when I was braking to see if the needle moved, and it did, almost imperceptibly. I've looked when I'm in EV, and it doesn't move at all. The little green "half-full" marking on the battery in the navigation system screen never changes--I had decided that the owner's manual must be wrong when it said that that graphic would indicate how much charge there was in the battery.

For what it's worth, I can go only about a mile in EV before the ICE kicks in--even when it's warmer than 60 degrees, even at slow (< 25 mph) speed, even with all accessories off, even after driving at highway speeds for more than 30 minutes. So I'm wondering if the battery is really charging up. Does this sound like something to take back to the technicians and ask about? (They have sold just 4 hybrids and so don't have a lot of experience with these.)

I'll try using L. Right now, I can see when the battery is being recharged (on the nav screen), but I have no way of knowing just how much charge is there.

 

For the record, the Charge/Assist needle does not move all that much. Maybe 1/8" during normal braking and 1/8" during normal acceleration. The only time it REALLY seems to move alot is during long slowdowns and during strong acceleration when the ICE gets a boost form the motors, and even then it is only for a second. You'll probably never see it go near either top or bottom of the gauge.

As for going more than a mile in EV...that is very normal, especially in a new vehicle. The range of the FEH/MMH tops out at about 2 miles on a full charge in perfect conditions. During the break-in phase either there are hard-coded limitations on the system or the battery is being conditioned so your ability to get into EV mode and stay in EV mode will be reduced. Until I had about 3000 miles on mine, I could never get past 25-30mph without the ICE coming on no matter how hard I tried. After 3000 miles I was able to get up to 35+ mph and cruise in EV for much longer.

The battery gauge on the Nav will change up and down, but 'FULL' is displayed as about 3/4 of the icon. If you look closely, you'll see that the area with the - and + are not illuminated.

Unless you are seeing mileage in the low 20's I would simply keep driving. If you still see problems once you've passed 3,000 miles then I would be concerned. Is it possible you didn't notice the MPG's when it came back from the shop? I know I've dropped mine off for service at 33mpg only to pick it up later that day at 24mpg. Undoubtedly, they were testing the vehicle while they had it and probably letting it run in the garage for much of that time.

 

Thats a good point... you only have 1,500 miles and there does seem to be some sort of breakin period where charging is less.

Mine has 20,000 Miles. If you punch the accelerator pretty hard (somewhere safe) I can usually see the guage swing pretty far.... during normal slow braking it won't swing nearly as much. When braking/accelerating I often WILL see it go maybe 5mm in either direction but it only does that for a second, then it will drop to just a mm or two from the middle. Thats from memory and I'll see if I'm right on the way home . If its wrong I'll re-post the correction but I'm pretty sure. Yeah some hypermiler is going to tell me thats why my mileage isn't "stellar" but thats how I drive... my MPG is good enough for me.

The one mile of travel on EV isn't all that unusual actually.... The battery isn't that large, essentially its designed more for storing braking energy and starting the engine than use as an EV vehicle. As such you can't go far in EV. Someone here said in exclusively EV mode about three miles is the max.... but you might not see that before its broke in a little too.

 

If you drove a mile in EV, you should have notice the green go down under the + and - (battery gauge) in the energy screen. It sounds like you don't know that the gauge is there. The green fill will drop to a thin line when the battery level is the lowest. This is the point when you get a restart of the ICE for no other reason. Many people who don't have the Nav system wish they had that gauge. This is the most important gauge (I thinK) available on the FEH.

GaryG

 

I knew it was supposed to be there, but, because it never moved, I assumed it was just a cute little icon and nothing more. I just now drove home, watched it carefully, and it never, ever changed. It always looks about half full.

I tried the L thing--I'll have to drive differently! For years I have coasted to stop signs (I drive mainly straight county roads) and I know just where I can let off the accelerator and still make it to the sign. Putting it in L was like putting on the brakes; I had to accelerate again in order to get to the stop sign. Seems like that would burn more gas, not less.

More pertinent to the question, braking in L (which was hard to do, as I was almost stopped anyway) didn't seem to send more charge to the battery. I watch that screen pretty closely, and I can tell when more or less charge is going to the battery, and putting it in L didn't make much difference. And the little half full battery gauge didn't change.

When I reach our subdivision, I can go all the way home (~2/3 mile) on EV. I watched it today. The little battery icon didn't change.

As for mileage, as I've always done in my cars, I reset between each fill-up. So any idling, etc. that the techs did has been erased.

Thanks for all your responses. I'm going to wait another month or so, until I get past 3000. If I'm still averaging 24 mpg, I'll take it in and let the tech figure out if the battery is charging properly or not.

 

Okay... I have to say that the Assist/charge guage definitely (at least how I drive) swings quite a bit! Just before the engine fires after leaving EV mode it will go at least halfway toward assist for a second or two. And as for charging... The whole time I'm pressing the brakes and slowing down its about halfway into the charge area. Moves almost a quarter inch and stays there for the entire brake sequence.

Whether that will happen on a vehicle that only has 1500 miles on it is another matter.

As for your MPG.... With only 1500 miles and in a midwestern state.... frankly 24 isn't that bad I'm afraid unless you are driving with alot of the hypermile tricks. I get about 26-27 if the temps are in the 30-40 range... it only gets into the 29-30's if its above 55F or so..

 

It's very hard for me to explain how to drive for MPG given the responses I get. I'm no gift to God's green earth, but less than 36mpg in a FWD or 33mpg in an AWD is nothing to write home about. After all, EPA was going to give the FEH a 40+ MPG rating, but Ford wanted to hold back that rating.

Unlike you people trying to get 30mpg, I am discussed I only got 45.9 mpg today. I had a heavey cross wind that would not leave me alone. For those who know detail, here is my todays readng from the the SG:

45.9 mpg
21 MPH AVG
44MPH MaX
2.8 HR
1.3 gallons
62.1 miles
182FWT max

We all have acceptable standards, these are not good in my opinion! No one had to tail gate me or cause a traffic flow problem.

GaryG