2010 Ford Fusion Hybrid electrical motor comes on less; mileage dropped

Hello, thanks so much for your email in July about the electrical motor in my 2010 Ford Fusion hybrid rarely coming on, which has gotten worse. I am finally following up about your suggestion of reseting the timer in the high-voltage system. Your Ford mechanic reset the timer back 10 years, per Ford’s instructions (although the car performed properly when he had reset it only 2 years).
Did the mechanic indicate what the probability is of the HVB quitting altogether? And if it does, what is the cost of replacing it? Your comments would be very helpful to me!
Thanks! Linda Moss

Hello Linda, The Ford dealer quoted about $7,000 for a new battery, but since Kelly blue book for trade-in is only about $2300, replacement doesn’t make sense. I’ve checked with other after market batteries and they sell for about $2500 so that still doesn’t make sense to replace. The service tech wouldn’t say how long the battery would work if the timer was set back, but I believe this is the same battery technology that is used in the prius and I know they last well past 10 yrs. The risk is that if the HVB goes bad the car won’t run at all. Hope that helps. Jim S.

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@Fins2l2r_154900 - Do you have any links that discuss this timer issue? I have a 2011 MKZ hybrid, wondering if it applies to it.

I found this, I haven’t tried it, so no guarantees:

Hello Jim,

Thank you so much for your help on this problem, which I am finally getting around to address.

Without your email in July, I never would have known about the HVB issue & the shut-off that Ford programmed in.

Your help motivated me to look further, & I discovered a lot of info available on the Web. In particular, there is a detailed account on a website called fordfusionforum.com (!) that tells exactly how to reprogram the HVB. It is written by allen84, & you might want to check it out (maybe I could send you a link, if needed). I also found a website called cargurus.com that has a lot of discussion of this issue.

We plan to visit an independent mechanic we know today & hope he might be able to take care of this for us!

Again, many thanks!

Linda Moss

@LindaMoss - Did you see the link I posted above?

Hi texases:

Sorry it took so long to respond. I’ve been communicating with another user on Car Talk about the problem and she found the following; In particular, there is a detailed account on a website called fordfusionforum.com (!) that tells exactly how to reprogram the HVB. It is written by allen84, & you might want to check it out.


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Thanks. I got the OBD plug, and I’ll be downloading the software shortly.

‘Hybrid’ is misleading. Some people think of “hybrid vehicles” as vehicles that encompass the best of two worlds, an ICE (internal combustion engine) vehicle world, and an EV (electric vehicle world). They utilize both onboard systems for propulsion in order to enhance fuel economy.

However, I have never looked at them as “best of 2 worlds vehicles”, but rather as overly-complicated vehicles that contain 2 worlds. In my opinion, any savings that results from improved fuel economy is off-set by complications, problems, and not much future for longevity.

I believe these vehicles should be used for probably a maximum of 7 or 8 years and then sold off before the problems start and continue until the pre-mature death of the vehicle. 10 years is pushing it, probably too far.

How much fuel savings could there possibly be in only 44,000 miles and 10 years? If this vehicle had been a conventional ICE vehicle it would just be getting broken-in at 10 years and 44,000 miles, not beginning breaking down. Since it’s not, I’d get rid of it ASAP and consider an ICE vehicle.
:palm_tree: :sunglasses: :palm_tree:

There are countless Prius owners with high mileage on the original batteries who would probably disagree with much of what you just said


Also, this is not a hybrid reliability problem, it’s a problem with how Ford did their programming.

You’re clouding the issue. The intent of hybrids is not to save money, it’s to use less gasoline. There’s a difference.

The benefit to hybrid technology is not suited to all driving styles. It sounds like your driving styles are not what most hybrid owners do. On the other hand, a driver in the Seattle area who has a daily 2 1/2hour 80 mile round-trip stop and go commute is likely to see mpg in the mid-40’s and see a service life of 200,000 miles before any seeing any repairs outside of routine maintenance.

But if you want to throw money into the equation, think about this. Your average GM mid-size sedan would be lucky to go 30,000 miles before needing a brake job. I have personally serviced Priuses that have gone 200,000 miles of urban driving on the original pads. The cost of 6 brake jobs adds up.

Let me put it another way. I would buy an 8 or 10 year old ICE vehicle (and I have), but I would not consider a “hybrid”. Feeling lucky?
:palm_tree: :sunglasses: :palm_tree:

I generally get about 100,000 miles out of mine. Last brake job I did on the Grand Prix, all 4 rotors and pads was $200. It didn’t even need them, but I bought the parts before checking, expecting to need them and put them on anyhow.

When I was in the rust belt during winters, rust was the enemy of brakes, not miles. Rust is an equal opportunity destroyer and ruins brakes on ICE cars and Hybrid cars, alike.

Here in Florida, everything seems to last a long time, except batteries.
:palm_tree: :sunglasses: :palm_tree:

I would have no problem buying a 8- or 10-year old Prius

Does that go for any brand? Do you think the battery would continue to function properly for several/many years or are you factoring in any necessary battery work/replacement/cell replacement? I’m curious and would like your opinion.
:palm_tree: :sunglasses::palm_tree:

If I was buying a used Hybrid, it would be a Toyota

It appears that you’re slamming hybrids in general . . . and you haven’t made it sufficiently clear why that is the case, at least in my opinion

Well, I don’t feel like discussing this further with you, because I feel the discussion would get nowhere

I’m not attacking you . . . I’m just saying I feel the discussion would be unproductive for all involved

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I have the same problem. The battery in my 2010 Mercury Milan has gone from 38-39 miles per gallon down to 30-31 recently. The battery charges fine , in fact it is usually close to fully charged. Is my problem the same or do I have a different problem?
Thank you.

It sounds like you have the exact problem I had, described above. The Ford programming is reducing the power from the battery. I reset the age of the battery, my mpgs went back up.

Well, I did the big reset (to 1 yr) as outlined at fordfusionhybridforum. Worked like a charm. Back to GREAT milage. Yes, the only concern is will the battery and car then rapidly die because it wasn’t designed to operate past 10 yrs.? What kind of deal is that, FORD?
The battery seems quite healthy (at 100,000 mi). It charges/decharges properly in the zone (or levels) it should. Going downhill, etc. I can get a FULL charge easily. I mean 100%.
Why would FORD or anyone suggest that the “fix” could be bad for the battery? Before the fix, due to not using EV so much, it often STAYED near 90 to 100% at times. From what I know about NiCd batteries, it is NOT good to not have more variable charge cycles. That is, ya need to cycle the battery through a moderate range (at least) constantly. That means, if we run the car without the fix for very long, the battery really will lose its viability. I got a local dealer to admit that principle. But, they refused to touch the car. What a mess!!