[UPDATED with Ford Norway's Response] Reports of Steep Downhills / Descents Overheating Mach-E

[dbsb3233]

I'm in California. Should I call my local dealer and ask for a service appointment?

I wouldn't unless you're driving frequent, steep switchbacks. The reports so far seem more consistent with driving that might use frequent extreme regen. Extreme regen isn't generated when rolling down an interstate on a 5-6% grade. That's probably only generating 8-12 kW (basically level 2 charging power).

But a steep grade on switchbacks means you're frequently speeding up and then regenning hard to slow down into the curves. It's that hard slowing (especially downhill) that's likely to hit max regen. And even though it's only 10 seconds at a time for each curve, doing that many times might be the issue. At least that's my speculation anyway, FWIW.

Many of us have been up/down I-70 in CO from the Eisenhower tunnel on 6% grade that goes on for many miles with no problem. But that's gradual, not tight switchbacks with frequent hard regen into tight curves.

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[TRP]

We have a section of road here that depends down to the South Fork of the Cumberland River that is 13% for a few miles. I haven't driven the MME on it yet. I rally don't think it's a long enough descent to cause a problem tho ?‍

 

[AndyR]

T

This was a pretty interesting article and reveals a similar issue to some of our friends in the West on steep mountain descents. Apparently in the last 14 days, six Mach-Es have bricked themselves from the heat generated during long downward slopes in this one little town. Ford has said that a patch will fix it, but it's currently only available at service centers and won't be OTAed until Sep/Oct.

https://translate.google.com/translate?hl=&sl=auto&tl=en&u=https://motor.no/bil/slik-skal-ford-fikse-mustanger-som-matte-berges-i-bakkene-ned-til-geiranger/204431

They werent "bricked". They shut down to PREVENT damage due to heat.

 

[AndyR]

I

Regen is much less aggressive without one pedal on. One pedal mode is like being in low gear, but with a complete stop. Unfortunately, Ford does not provide a KW display so that you can see it, but GM does this and it is very useful info.

Plus, going downhill at 75mph, I will not be applying brakes.

I have a ODBII dongle that will read the regen amount. I'll try to measure the different modes at different speeds and report back.

 

[ARK]

Unless you touch the brake pedal. Which you probably will be if it's a steeper downhill than coasting grade.

At least that's my understanding - that the brake pedal still uses regen first, and only adds on friction braking if you max out regen (regardless of drive mode).

I was wondering this too, it would be interesting to know - whether when a Mach-E slams the brake pedal you always get max regen braking along with the friction brakes.

If so, I wonder how anti-lock braking would work in this scenario, perhaps regen does disable or the braking power of motor regen isn’t enough to mess with the anti-lock function. I suppose this question applies generally to all BEVs with regen.

 

[ajmartineau]

I have a few mountains around where I live with no issues.
Here is a picture from near the bottom of one of them.

 

[Frankie]

I have a ODBII dongle that will read the regen amount. I'll try to measure the different modes at different speeds and report back.

If you're going the exact same speed under the exact same conditions the regen is going to be the exact same no matter what mode you're in. If one mode was regenning more that would mean you'd be slowing down, if one mode was regenning less you would be speeding up. That's just physics. Like, where do you think the extra regen would be coming from? Any difference you would measure would be differences in grade or wind.

Yes, 1PD obviously regens more when you take your foot off the go pedal, but we're talking about maintaining a steady speed going down a hill.

 

[Kamuelaflyer]

T



They werent "bricked". They shut down to PREVENT damage due to heat.

Bricked enough. The vehicles shut down and had to be flat bed towed to a dealer for an update/repair. That's pretty much bricked.

 

[AndyR]

If you're going the exact same speed under the exact same conditions the regen is going to be the exact same no matter what mode you're in. If one mode was regenning more that would mean you'd be slowing down, if one mode was regenning less you would be speeding up. That's just physics. Like, where do you think the extra regen would be coming from? Any difference you would measure would be differences in grade or wind.

Yes, 1PD obviously regens more when you take your foot off the go pedal, but we're talking about maintaining a steady speed going down a hill.

agree on coming down hill and maintaining steady speed.

My test would be same beginning speed, foot off of accelerator, how much does each mode generate as you slow down. Flat road.

 

[AndyR]

Bricked enough. The vehicles shut down and had to be flat bed towed to a dealer for an update/repair. That's pretty much bricked.

Bricked tends to mean permanently broken.

 

[Kamuelaflyer]

Bricked tends to mean permanently broken.

nope.

 

[AndyR]

nope.

yep

 

[Shayne]

Uphill both ways.

Regen on the descent results in miles per kWh ranging from the 7’s to as high as 10.1. I usually lose about 3% soc in the first 4 Mike’s of a trip to Kona. By the time I get to the bottom of the cross island highway, I’ve regained all of that loss. If I’m driving close to the speed limit, there’s enough rolling hills trending downwards that the 40 mile drive results in a loss of 6 to 7%.

The return? 2.1 to 1.6. This is why the GOM is stuck at 220.

If I start at 100% I find I lose 0% for the first 25 km (16 mi). You think it only uses your last trip in the determination as it believes you are not high enough yet? (7.5 + (2.1 + 1.6)/2)/2 = 4.7 mi/Kw average? How fast are you driving average up and down? 220 mi range for an x sounds a bit wrong and average consumption says different. What happens to the GOM when you run it down is it 1:1 with actual distance traveled or is it not linear? Me I am not the faint of heart and am above 400 km range with 22 Kw/100km. On a 88 Kw pack makes the math pretty simple. The GOM has always reflected fairly accurately in mine. I am getting better and have seen below 20 lately but still like to scoot. Switch yours to metric and see what happens .

yep

I say brick because what is it good for? A paperweight? If we can bring it back to function again it is not a brick.

 

[AndyR]

If I start at 100% I find I lose 0% for the first 25 km (16 mi). You think it only uses your last trip in the determination as it believes you are not high enough yet? (7.5 + (2.1 + 1.6)/2)/2 = 4.7 mi/Kw average? How fast are you driving average up and down? 220 mi range for an x sounds a bit wrong and average consumption says different. What happens to the GOM when you run it down is it 1:1 with actual distance traveled or is it not linear? Me I am not the faint of heart and am above 400 km range with 22 Kw/100km. On a 88 Kw pack makes the math pretty simple. The GOM has always reflected fairly accurately in mine. I am getting better and have seen below 20 lately but still like to scoot. Switch yours to metric and see what happens .


I say brick because what is it good for? A paperweight? If we can bring it back to function again it is not a brick.

A brick, by definition, can't be brought back to life. Just sayin

 

[jlauro]

yep

Good point correcting yourself, brick typically but as defined doesn't always mean permanent basis.

I agree with Kamuelaflyer that this classifies as bricked, especially if the car didn't say something like wait for vehicle to cool. If all the driver knows is it doesn't work, then it's bricked even if waiting would fix itself. (and it's not clear from the story if it would of fixed itself or not if given time to cool).