New 12v battery and reset BMS but still getting “update failed because vehicle battery too low message

[SeanOC]

Hey guys. I’ve been getting update fail message because vehicle battery too low the past week. Truck is 3.5 years old and 50k miles, I went ahead and put a new 12v in and upgraded to the H4. I reset the BMS after install.

Unfortunately I’m still getting message a few days later. Vehicle is charged to 90% and left plugged in overnight (updates scheduled for 2am).

Any thoughts?

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[TaxmanHog]

Try switching the headlight to OFF.
Switch off the sound system.
Switch off truck.
Set parking brakes.
Start Install now.
Get out & Lock doors.
Force stop your mobile app easy to do in Android, not sure how you do it in iOs.
Walk away with FOB and leave them still in the house/office for the projected duration of the install.

Hopefully you have success

 

[rpritchett2]

I had exact same issue. Tried the resets, but no joy. Took my truck to dealer and tech reset BMS with his Forscan tool. They also took care of some recall issues.

 

[Sleazy-E]

Hey guys. I’ve been getting update fail message because vehicle battery too low the past week. Truck is 3.5 years old and 50k miles, I went ahead and put a new 12v in and upgraded to the H4. I reset the BMS after install.

Unfortunately I’m still getting message a few days later. Vehicle is charged to 90% and left plugged in overnight (updates scheduled for 2am).

Any thoughts?

Check the BMS part number. This caught me when I bought used and was having the same exact issue.

https://www.f150lightningforum.com/...nc-cold-weather-performance.34418/post-651587

 

[Tony Burgh]

Try switching the headlight to OFF.
Switch off the sound system.
Switch off truck.
Set parking brakes.
Start Install now.
Get out & Lock doors.
Force stop your mobile app easy to do in Android, not sure how you do it in iOs.
Walk away with FOB and leave them still in the house/office for the projected duration of the install.

Hopefully you have success

Then you do the Hokey Pokey and you turn yourself about.

 

[Boomerboy]

Hey guys. I’ve been getting update fail message because vehicle battery too low the past week. Truck is 3.5 years old and 50k miles, I went ahead and put a new 12v in and upgraded to the H4. I reset the BMS after install.

Unfortunately I’m still getting message a few days later. Vehicle is charged to 90% and left plugged in overnight (updates scheduled for 2am).

Any thoughts?

When I replaced my 12v and reset the BMS truck did not totally reset the BMS until I drove the truck about 30 miles. After driving the truck 30 miles then letting the truck set overnight everything was fine.

 

[tearitupsports]

A couple of notes.
Just having the truck plugged in does not maintain or charge the 12V battery. It is only charging when the truck is "ON" or when it is actively charging the HV battery.
Low 12V battery is quite normal for people who make frequent but short trips and thus short charging sessions.

The ideas above are what you need to do. Keep the truck "ON" for several hours by turning off the 30 minute timer, and shutting off the lights as well as the AC system. This will work for most people.

As noted above, make sure you have the correct battery monitor part as well. 22 and 23 trucks had a recall for the battery monitor, and I don't think all vehicles had this completed. The link posted above will take you to another link that shows how to read the bad and good part numbers.

 

[SeanOC]

Yes unfortunately I have the an early ‘22 model and I have one of the recalled BMS sensors.
Will call the dealer on Monday.
I’ve tried all the other recommendations listed above but not luck, thanks everyone for the advice.

 

[chl]

Yes unfortunately I have the an early ‘22 model and I have one of the recalled BMS sensors.
Will call the dealer on Monday.
I’ve tried all the other recommendations listed above but not luck, thanks everyone for the advice.

Yes, I concur that if the normal ways to solve the issue didn't work, then likely a bad component in the 12v system, as others mentioned, and a trip to the Ford tech or dealership is the last resort...er, uh, I mean the easiest solution.

Keep us posted on the solution and the $damage$.

 

[jwrezz]

Check the BMS part number. This caught me when I bought used and was having the same exact issue.

https://www.f150lightningforum.com/...nc-cold-weather-performance.34418/post-651587

https://www.f150lightningforum.com/...ngs-bms-sensor-replacement.17900/#post-359823

 

[chl]

https://www.f150lightningforum.com/...ngs-bms-sensor-replacement.17900/#post-359823

You could always get the part yourself and hope that does the trick, however there could be other things going on so it's a crap shoot.

 

[SeanOC]

Check the BMS part number. This caught me when I bought used and was having the same exact issue.

https://www.f150lightningforum.com/...nc-cold-weather-performance.34418/post-651587

Thank you! I have one of the bad part numbers. My truck is an early ‘22 model

Yes, I concur that if the normal ways to solve the issue didn't work, then likely a bad component in the 12v system, as others mentioned, and a trip to the Ford tech or dealership is the last resort...er, uh, I mean the easiest solution.

Keep us posted on the solution and the $damage$.

should be covered under my extended warranty or the recall, but yes I will definitely update here

 

[chl]

Thank you! I have one of the bad part numbers. My truck is an early ‘22 model


should be covered under my extended warranty or the recall, but yes I will definitely update here

Good for you getting an extended warranty - I did the same!

 

[Tfarrell73]

That was CSP not a recall. I believe CSPs do expire but not sure about specifics for the BMS CSP 23B70

 

[chl]

That was CSP not a recall. I believe CSPs do expire but not sure about specifics for the BMS CSP 23B70

Yes, that one expired Jan 2025 I believe, but under the extended warranty since it seems to be failing, should be covered.

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