Hello,

I have a 2006 Ford Escape Hybrid (2WD) with about 15000 miles on it. About a week ago, I noticed a sudden change in how it drives when the stick is shifted into the 'L' position. In the past, the 'D' position seemed to roll much better and the 'L' position would slow down faster (much like a manual transmission on a standard car). When in the 'L' position, the battery would recharge as it coasted (and slowed down). I was use to this mode of operation and used the 'L' position when approaching traffic jams or when the general flow of traffic was slowing down and I didn't want to use the brake.

Over the last week, my car seems to charge normally in the 'L' position while slowing down, but there is almost no almost difference between the 'D' and 'L' positions when slowing down. In other words, I definately have to use the brakes in 'L' when in the past I would have a much smoother speed reduction using just 'L'. A few days before I noticed this change in behavior, I heard a loud thump in the right rear of the car while I was on the freeway. At the time, I thought that there may have been something on the road I did not see.

I took the car into a local dealer and they drove it and said everything was normal. Well, if this is normal, what it was doing before was very different! I drive the same road every day and if I'm on a flat section going 40 mph, if I coast in 'L' for a tenth of a mile or so, I would have slowed down to about 10 mph. Now if I do the same thing, I will be gong close to 30 mph after the same distance.

Any ideas on what happened? Should I take it to a different dealer?

Thanks,

Doug

 

What you describe sounds like regen braking is no-longer occurring per the designed amount when you drive in "L". Have you noticed a significant drop in SoC level on your NAV/HYB screen?....or maybe do you notice the ICE running more often....to charge the HVBattery (to keep up the SoC)?

 

Hi Doug

The PCM controls the amount of regen you get based on a number of factors. HV battery SoC, battery temp, outside temp. traction motor temp etc, which can effect the amount the PCM will allow regen to the battery. If charging seems to be the same from regen, I'm not sure you have a problem either. If there is a problem, it's more than likely software.

Your weather is in the upper 40's in the AM, and that temp here reduces "L" regen for me until the battery gets warm. But when it's warmed up in the 70's like your afternoons, regen should be like it has always been. If I snap the gas pedal off real fast, it seems I get heavier regen than if I slowly let off. Sometimes though, I get light regen in "L" and have to make sure the shifter is in "L" by looking down at it.

The big question is, how do you coast down a tenth of a mile in "L" under 40mph and not go EV. When this happens to me, the battery does not want the fast charge and tells the PCM to reduce regen. This would cause you to coast much further in "L". If I don't see that idle reduced for EV within a second or two, that is the problem. What I do is shift to "N" and lightly tap the brakes to go EV. After a little EV after that, I get normal regen which is heavy like it should be in "L".

The FEH/MMH has some strange reactions sometimes, and I've figured how to get around them on a daily basis for a while now.

GaryG

 

Doug, before we post more "theories" take a look at the battery icon on the Nav when you are using "L". A nearly full battery, or cold battery will cause exactly what you describe... a reduction in regen, and thus slowing power.

If the battery is cold or more than 50% green, you most likely don't have any problem.
If the battery is warm ( 60'F + ) or the battery icon is mostly black, then most likely you do have a problem.

-John

 

Under the left rear corner of the vehicle there are rather vulnerable a/c lines for the HV battery (I know you said you heard the loud thump from the right rear corner). I would atleast inspect the lines for damage, since the aux. a/c unit is part of the cabin a/c just verify if your a/c works. Who knows maybe it is a HV battery temp. control issue.

 

Thanks for all of the suggestions. My AC works, and my battery charging appears to be just about the same. I run the HV battery down all the way from time to time driving ~25MPH around my neighborhood and it seems to recharge in the same amount of time. The real MPG calculated by miles driven and gas used is about the same for the last two tanks. The only difference I see is a reduction of drag in 'L' so I have to use my brakes more and the NAV system is reporting a better MPG reading (but it is not translated to actual fuel economy.

Doug