MarleysMME

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[Updated with response from Ford Norway]

Courtesy of Motor.no:




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
This is what I reported a few weeks ago as well as another owner in New Hampshire. I suspected a softer bug...

https://www.macheforum.com/site/threads/going-downhill-car-won’t-start.7455/post-200767
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Very interesting that there are no updates to this thread since July! This happened to me yesterday in the Great Smoky Mountains National Park. I descended from Newfound Gap (elevation just over 5,000 feet) to Sugarlands Visitor Center (elevation about 1,500 feet), with a 20 minute stop at Chimney's Picnic Area. At about 2,000 feet my Mach-E beeped, displayed a red error message on the drive display area ("vehicle drive disengaged" or something similar), and stopped regenerative breaking. I was in Unbridled mode but did not have one pedal driving engaged.

I continued to coast down the hill, slowing via brakes, and turned into SVC parking area. (Thankfully there were no obstructions and the second parking spot was available - rare on an October afternoon.) The vehicle would not turn off; pressing the power button resulted in it blinking. I tried to be nonchalant since my wife and grandson were with me and had another agenda at SVC, so when the car finally did turn off we walked into the Visitor Center. When we returned after about 15 minutes, the car started and we drove home with no problems.

I plan to report this to my dealer and plan a service visit / 10,000 mile maintenance event next week.
 

Shayne

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Very interesting that there are no updates to this thread since July! This happened to me yesterday in the Great Smoky Mountains National Park. I descended from Newfound Gap (elevation just over 5,000 feet) to Sugarlands Visitor Center (elevation about 1,500 feet), with a 20 minute stop at Chimney's Picnic Area. At about 2,000 feet my Mach-E beeped, displayed a red error message on the drive display area ("vehicle drive disengaged" or something similar), and stopped regenerative breaking. I was in Unbridled mode but did not have one pedal driving engaged.

I continued to coast down the hill, slowing via brakes, and turned into SVC parking area. (Thankfully there were no obstructions and the second parking spot was available - rare on an October afternoon.) The vehicle would not turn off; pressing the power button resulted in it blinking. I tried to be nonchalant since my wife and grandson were with me and had another agenda at SVC, so when the car finally did turn off we walked into the Visitor Center. When we returned after about 15 minutes, the car started and we drove home with no problems.

I plan to report this to my dealer and plan a service visit / 10,000 mile maintenance event next week.
May be best to report it as a problem now (call them) and that you need it fixed. They may have the software available there and they can source it before hand; not when you are sitting there?

It will be good to hear your follow up and out come as it was noted to be coming OTA September October just 2 posts above. Not sure if this minor fix is coming with the must have tic tac toe? ;)
 

dbsb3233

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An obvious question is... Do many (or all) of us have this potential problem sitting in ours, but we just haven't experienced it yet because we haven't gone down long steep switchbacks where we keep hitting regen hard into the sharp corners?

It does appear the problem (overheating of some kind?) clears itself and returns to normal after it's allowed to rest and cool down, so that's good. But still.
 

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Very interesting that there are no updates to this thread since July! This happened to me yesterday in the Great Smoky Mountains National Park. I descended from Newfound Gap (elevation just over 5,000 feet) to Sugarlands Visitor Center (elevation about 1,500 feet), with a 20 minute stop at Chimney's Picnic Area. At about 2,000 feet my Mach-E beeped, displayed a red error message on the drive display area ("vehicle drive disengaged" or something similar), and stopped regenerative breaking. I was in Unbridled mode but did not have one pedal driving engaged.

I continued to coast down the hill, slowing via brakes, and turned into SVC parking area. (Thankfully there were no obstructions and the second parking spot was available - rare on an October afternoon.) The vehicle would not turn off; pressing the power button resulted in it blinking. I tried to be nonchalant since my wife and grandson were with me and had another agenda at SVC, so when the car finally did turn off we walked into the Visitor Center. When we returned after about 15 minutes, the car started and we drove home with no problems.

I plan to report this to my dealer and plan a service visit / 10,000 mile maintenance event next week.
Don’t forget that Unbridled mode has the most aggressive regenerative braking. Switching to Whisper mode might reduce the chance of over-heating on descent. Or, if you have a GT and the battery is cool enough, SoC is right, etc. Unbridled Extend might help. These are all guesses on my part since I am still a charter member of the Grumpy thread.
 

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An obvious question is... Do many (or all) of us have this potential problem sitting in ours, but we just haven't experienced it yet because we haven't gone down long steep switchbacks where we keep hitting regen hard into the sharp corners?

It does appear the problem (overheating of some kind?) clears itself and returns to normal after it's allowed to rest and cool down, so that's good. But still.
I would say of course that is the case it is just a certain condition that we have not subjected it to yet. We have no form of temperature gauge in these vehicles so hard to tell if we have even pushed it a couple of time. Definitely flashing a bunch of error messages at you is not something we can monitor. Motor and battery temps would be nice.
 

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It does appear the problem (overheating of some kind?) clears itself and returns to normal after it's allowed to rest and cool down, so that's good. But still.
I don't think we can say it's overheating... I think it fairer to guess that it's a software bug, not handling values at some edge conditions and reacting poorly to the "exceptional" numbers... But we can't really say anything for sure since Ford hasn't divulged specifics.

I would say of course that is the case it is just a certain condition that we have not subjected it to yet.
Exactly.
 

Timelessblur

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Don’t forget that Unbridled mode has the most aggressive regenerative braking. Switching to Whisper mode might reduce the chance of over-heating on descent. Or, if you have a GT and the battery is cool enough, SoC is right, etc. Unbridled Extend might help. These are all guesses on my part since I am still a charter member of the Grumpy thread.
I do not think it is the batteries over heating but the inverters and motors over heating. The batteries can take a much higher load than those for a sustain period of time.
 
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ARK

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Don’t forget that Unbridled mode has the most aggressive regenerative braking. Switching to Whisper mode might reduce the chance of over-heating on descent. Or, if you have a GT and the battery is cool enough, SoC is right, etc. Unbridled Extend might help. These are all guesses on my part since I am still a charter member of the Grumpy thread.
Regen braking is unavoidable on the Mach-E though. When you press the brake pedal, you first go through regen braking before the friction brakes are engaged (if you press hard enough).

So whether you are in Unbridled with 1PD on and going down a steep mountain with your feet off both pedals holding a steady speed, or in Whisper with 1PD off and your foot mildly/moderately on the brake pedal the whole way down the same mountain holding the same steady speed, the amount of regen the vehicle is generating should be the same.

Much of the misimpression over this comes because of how Tesla handles it, being the 1,000 pound gorilla in the room and all when it comes to EVs. A brake pedal on a Tesla works just like on an ICE - no regen is generated when you step on it. So in a Tesla, if you are using the brake pedal, it means you are not relying on regen to slow down, it’s a normal friction brake.

This is not the case with the Mach-E and some other EVs - the Mach-E has blended braking, as described above. 1PD on the Mach-E is more for preference in footwork, it doesn’t impact your ability to access or rely on regen to slow down. Whether the vehicle is automatically initiating regen when you lift off the accelerator pedal or calling it up only when you press the brake pedal, the result is ultimately the same.
 

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I don't think we can say it's overheating... I think it fairer to guess that it's a software bug, not handling values at some edge conditions and reacting poorly to the "exceptional" numbers... But we can't really say anything for sure since Ford hasn't divulged specifics.
I say "overheating" because the pattern suggests whatever is causing it seems to be cooling down after resting, allowing the car to function like normal again. So it appears the root cause is something getting warm/hot.

But yeah, since they seem to be fixing it with a software fix, it may be that whatever it is is only getting modestly warm and the threshold just needed to be raised. Or the new software modifies the cooling system parameters. Or something else like that. Don't know. But the behavior triggering it seems like something getting warm/hot beyond current software parameters can deal with.
 
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macchiaz-o

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I say "overheating" because the pattern suggests whatever is causing it seems to be cooling down after resting, allowing the car to function like normal again. So it appears the root cause is something getting warm/hot.

But yeah, since they seem to be fixing it with a software fix, it may be that whatever it is is only getting modestly warm and the threshold just needed to be raised. Or the new software modifies the cooling system parameters. Or something else like that. Don't know. But the behavior triggering it seems like something getting warm/hot beyond current software parameters can deal with.
Or it resets because of key off, wait five minutes (timer), key on. 🤷‍♂️
 

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Curious: if you go down one of these steep hills for long enough, does the battery meter tick back up? When you get the error, is the battery full?
 

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I could be remembering wrong but I thought when Darren Palmer was on the InsideEVs podcast, he made a quick passing reference to this issue and said it was being worked actively on. This sort of aligns with the Ford Norway response but sort of doesn't, since he implied it wasn't actually fixed yet?
 

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For whatever reason Ford, takes way to long to solve anything that has to do with the MME and doesn't tell their dealer's Sh...it!
 

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I do not think it is the batteries over heating but the inverters and motors over heating. The batteries can take a much higher load than those for a sustain period of time.
Actually yeah, you’re right. The motors are probably the culprits here, in which case Unbridled Extend on a GT *might* be a help, but there isn’t much else that will help unless the car has a software update to prevent this.
 
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