- First Name
- Dec 30, 2019
- Reaction score
- Colorado, USA
- 2021 Mustang Mach-E FE Red, 2013 Escape Titanium
Yes, the battery meter ticks back up with enough downhill grade (in my experience, the break-even point with climate control on seems to be around 5% downhill grade).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?
You are right to report this to your dealer and get it in for service right away. Trust me I have first-hand knowledge on this happening to someone else and it was way worse.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.
The drive modes just change the amount of lift off regen you get, with less in whisper and oddly more in unbridled. As I have the power meter on the dash I don't really seen a visual bump between the modes when lifting off, maybe if Ford had not made the bar microscopic in size I would , it is not a huge difference. I can't comment on 1pd as I have it switched off. I live in a hilly area simply going down hills with the cruise control on quickly kicks in regen which increases as needed which results in a very stable cruise control speed.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.
A good question Tim. I routinely drive to Kona and start out with about a 6,000-foot descent in just under 7 miles. No problems with that (yet. Knock on wood.). Engage mode with 1pd on.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've done a number of descents from over 11,000' summits without any problem, but always on interstate highways using gentle, consistent regen. Not hard regen. So far the problem pattern appears to be when there's a series of many switchbacks. People repeatedly hit the regen hard on those tight 180' turns over and over, with speed-ups in between each one. I'm guessing that's the difference.A good question Tim. I routinely drive to Kona and start out with about a 6,000-foot descent in just under 7 miles. No problems with that (yet. Knock on wood.). Engage mode with 1pd on.
Usually? But not necessarily in this case? See @RonTCat's hint here: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.
Oh wow, I never saw that post. Well that's curious then. I wonder what's actually triggering it?Usually? But not necessarily in this case? See @RonTCat's hint here:
I do believe that 21-2245 is the correct one for the downhill issue where the software doesn't correctly handle very high values of regen, with the resulting software panic resulted in an overreaction and vehicle shutdown.Update: I had my car in for service to correct the drive train disengagement problem. As I understand it, the fix they put on was TSB 21-2245, which doesn't sound exactly like my problem. Does anyone know the TSB to fix the overheating while regenerating going down hill problem (a la Norway)? (The last post above sounds logical to me: 12 V battery discharged due to running cooling fans - the red 12 battery icon was lit on my dash for a while after the problem occurred.)
Thanks for the quick update! I will test this at my first opportunity...which may be a few weeks...I do believe that 21-2245 is the correct one for the downhill issue where the software doesn't correctly handle very high values of regen, with the resulting software panic resulted in an overreaction and vehicle shutdown.
The red 12V battery icon stays lit while the car is in Accessory mode instead of Ready (to drive) mode. This is relatively normal... Just saw it today on mine while I was filling tire pressure.
I tested this last weekend. During the original failure, I had driven up to about 5,500 feet then started down to 1,300 feet, with 2 15 minute stops; the failure occurred at about 1,600 feet elevation. During the test last weekend, I drove up to the Clingman's Dome parking log (about 6,280' elevation) and descended without stopping all the way to Gatlinburg: an uneventful journey, so I guess TSB 21-2245 *did* fix the problem. Yay! (Only caveat is that it was about 15 degrees F colder last weekend than on the day of the drive train failure.)Thanks for the quick update! I will test this at my first opportunity...which may be a few weeks...