Connected to Charger Error & Won't Shift Out of Park. Lesson learned: carry a 10mm wrench (to disconnect battery)

[subseavet]

How long have you been using the OHMMU battery?
I understand it has its own BMS. Has that presented any issues with the truck's BMS?
Is the OHMMU BMS integral to the battery, or is it a separate device?

I've been using it since January 2024 and have not had any issues. The built-in BMS is entirely separate from the truck's BMS, so they don't talk, and there aren't any problems. Both are working. I know many people have thoughts (positive and negative, no pun intended) on the OHMMU battery. So far, I'm totally satisfied with mine.

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[Lytning]

So I keep one in my trunk/frunk after reading how people had issues after a software update. Not saying this was the culprit, more that this makes me wonder if we should just do a nice cold reboot once every quarter or 6 months or so. Kind of like back in the old Windows days. I'm 20 years from doing help desk work, but way back in the day it helped if you pulled the power from a workstation, hit the power button while the power was disconnected, then power it back on. A nice cold boot really helped keep the calls down.

So maybe we should disconnect the power cable for 20-30 minutes every x number of months? Just treat this like Windows 95 for now

This may actually be a great suggestion. I have to reboot my iPhone about once per month. What I notice is that random text messages are not delivered. Some come through, but others do not. (Try convincing your wife that you really did not receive the text she sent you.) After a reboot, all the undelivered texts magically appear. I also have to reboot the Xfinity gateway modem / router once per month to solve stuttering TV audio.

 

[FirstF150InCasco]

A few months back, someone warned us about having the 10 MM wrench handy. I bought one and put it in my console. Hope I never need to use it!

 

[Whammy Bar]

Yeah, that's a bad issue to run across. I have a basic toolkit, roadside emergency kit, and survival kit in every vehicle I own. You never know when having something as simple as a wrench or pair or pliers being the difference between a mild inconvenience and being stranded in a life-threatening situation.

I have an idea for an essential Ford EV repair kit:

A 10mm box wrench and an instruction sheet with one simple line: "Power cycle it."

For the amount of times one is required to powercycle this damn thing, Ford should just put a 100A breaker right next to the battery.

You could retrofit one like this, then it would be just as simple as resetting a GFCI.

 

[Pioneer74]

For the amount of times one is required to powercycle this damn thing, Ford should just put a 100A breaker right next to the battery.

You could retrofit one like this, then it would be just as simple as resetting a GFCI.

2 years and 50k miles later, I have never had to pull the negative terminal on my Lightning.

<knock on wood>

 

[Whammy Bar]

2 years and 50k miles later, I have not had to pull the negative terminal on my Lightning because I just have it towed to the dealer.

<knock on wood>

Fixed it for ya. I think at least 1 of those is what you probably meant.

 

[Pioneer74]

Never been towed either.

 

[queuewho]

2 years and 50k miles later, I have never had to pull the negative terminal on my Lightning.

<knock on wood>

Same, I did try to pull some various fuses to fix my modem once, but I think it ended up being a system wide outage and not just me. I think it's such a simple thing to keep a wrench handy incase.

I still have to get the bms thing replaced. Been lazy on that one.

 

[TreatYoSelf]

.
If you don't have a 10 mm wrench, you surely need to get one.

Super helpful. Thanks for sharing. Adding this wrench to my 12V jumper bag.

 

[B177y]

Today I experienced an error that I do not recall seeing on the forum. I also searched and did not find the issue, but I could have missed it.

I was running errands and after my third stop, when I started my truck it would not shift out of park. An icon on the dash display erroneously showed that the truck was connected to a charger, and there was a pop-up message to disconnect from the charger. (I was not connected to a charger.) I started and powered off several times, pushed the release button at the the charge port several times, and re-booted the main screen, all without eliminating the error. On two occasions upon starting the red 12 volt battery icon displayed. I plugged in a cigarette lighter USB charger with a voltage display. It showed 13.6 volts with the truck started and 12.5 volts when powered off. Everything else seemed to work properly. The AC was running, both displays were normal except for the connected-to-charger icon on the dash display, and the frunk opened properly. I have had the 12 volt BMS module replacement completed.

I pulled out the 10 mm wrench I purchased 18 months ago and lifted the negative cable off the 12 volt battery. I waited about a minute and reconnected the cable to the battery. The connected-to-charger icon was no longer present on the dash display, and the truck would now shift out of park. If I did not have the 10 mm wrench, I would still be sitting in the parking lot waiting on a tow truck to the dealership. I checked the battery status with an OBDLink MX+ and CarScanner when I returned home (only 1 mile distance), and found 12 volt SOC at 80% per the attached photo. Although the display is showing 102 degrees, the ambient temperature is 85 degrees. The truck is parked in the sun after driving it, so heat from the radiator is likely affecting the display temperature.

If you don't have a 10 mm wrench, you surely need to get one. This is the first time I have had to use mine. I am not a fan of using a 12 point wrench on hex head nuts. I have a 6 point box end / open end wrench, but it was a bit unwieldy. Here is a link to a ratcheting 10 mm 6 point wrench that I just ordered.
https://a.co/d/6KFPqRY

@rugedraw recently recommended one of these 12-volt battery switches:

https://www.amazon.com/IMAYCC-Batte...0D2K7CV69/ref=cm_cr_arp_d_product_top?ie=UTF8

I can't find which thread him and @Mike G were discussing it. It may have been on the Mach-e forum.

After reading about your experience, I finally ordered one.

 

[rugedraw]

@rugedraw recently recommended one of these 12-volt battery switches:

https://www.amazon.com/IMAYCC-Batte...0D2K7CV69/ref=cm_cr_arp_d_product_top?ie=UTF8

I can't find which thread him and @Mike G were discussing it. It may have been on the Mach-e forum.

After reading about your experience, I finally ordered one.

We momentarily derailed the FDRS thread here to talk about this recently. Very happy with it.

https://www.f150lightningforum.com/...software-updates-using-fdrs.11029/post-427296

 

[GarageMahal]

Yes as electrical engineer buddy always said and I live by today. "If all else fails reboot"
He worked for Northrop on the blackbird. Also Triple A responsible for setting up communications antennas on California mountains and what we know of today as cellphone service.
Rest in piece Jonith Johnson.

Sadly today's world is "Reboot first and hope it fixes it since nobody knows how to do anything else"

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