• Welcome to F150Lightningforum.com everyone!

    If you're joining us from F150gen14.com, then you may already have an account here!

    If you were registered on F150gen14.com as of April 16, 2022 or earlier, then you can simply login here with the same username and password!

Sponsored

MME 12v battery issues

Rob G

Well-known member
First Name
Rob
Joined
Apr 19, 2022
Threads
12
Messages
274
Reaction score
229
Location
Monmouth County NJ
Vehicles
GV60 Sport, Bronco BL Sasquatch, Taycan 4S
Occupation
Retired
It seems there are some serious issues plaguing the MME that I’ve read about on the sister forum that result in a dead 12v battery. I’m curious if the Lightning will have the same flaw. It’s concerning because about 40 forum members have had issues that has an unknown cause effecting several parts that lead to a dead 12V and a disabled car.

https://www.macheforum.com/site/thr...ers-biggest-fear-facts-and-info-thread.18143/
Sponsored

 

beatle

Well-known member
Joined
Jun 1, 2021
Threads
23
Messages
885
Reaction score
980
Location
Springfield, VA
Vehicles
Model S, Ridgeline, Miata, motorcycle(s)
Sounds like the 12v battery dying is just collateral damage from a HVJB failure. That thread says the HVJB is not a unique component to Ford, so it could conceivably be used among different models with the same battery voltage. I'm not sure if it has to be rated for certain amounts of current though. The MME GT uses the same component but still doesn't have the same power as the Lightning. We'll just have to wait and see if it is shared and has the same defect.

It's nice that Ford includes a lot of components in their 8 year / 100k mile EV warranty. The HVJB is not called out specifically but this page also says it is not limited to this list of electrical components:

https://help.ford.com/warranty/hybrid-electric-vehicle-unique-component-coverage/

Fortunately Ford's EV component warranty is better than Tesla who will tell you to pound sand and pony up if your HV battery fuse blows, if your battery heater goes out, or if your onboard charger fails beyond the bumper to bumper warranty.
 
OP
OP

Rob G

Well-known member
First Name
Rob
Joined
Apr 19, 2022
Threads
12
Messages
274
Reaction score
229
Location
Monmouth County NJ
Vehicles
GV60 Sport, Bronco BL Sasquatch, Taycan 4S
Occupation
Retired
I’m not concerned about Ford covering it. I’m concerned about being stranded on a road trip given it seems to be fairly prevalent. I’m concerned that you may not be able to depend on the vehicle (at least the MME).
 

sotek2345

Well-known member
First Name
Tom
Joined
Jun 7, 2021
Threads
29
Messages
3,535
Reaction score
4,076
Location
Upstate NY
Vehicles
2022 Lightning Lariat ER, 2021 Mach-e GT
Occupation
Engineering Manager
Those issues mainly seemed to plague the earlier builds. I know there was a software update that solved the fast majority of the problems (LVB wasn't being recharged correctly from the HVB). We have had no issues with ours.
 

Maquis

Well-known member
First Name
Dave
Joined
May 20, 2021
Threads
8
Messages
2,869
Reaction score
3,478
Location
Illinois
Vehicles
2021 Mach-E E4-X; 2023 Lightning Lariat ER
Those issues mainly seemed to plague the earlier builds. I know there was a software update that solved the fast majority of the problems (LVB wasn't being recharged correctly from the HVB). We have had no issues with ours.
I second this. I think all the cars with the issue were job 1 (pre-July builds) and have been fixed by software update. I won’t be worrying about this if I ever get a Lightning!
 

Sponsored
OP
OP

Rob G

Well-known member
First Name
Rob
Joined
Apr 19, 2022
Threads
12
Messages
274
Reaction score
229
Location
Monmouth County NJ
Vehicles
GV60 Sport, Bronco BL Sasquatch, Taycan 4S
Occupation
Retired
I have a 2022 GTPE as well and it’s a very recent build. I’m hopeful to not have this issue.
 
Last edited:

RickLightning

Well-known member
Joined
Jan 17, 2022
Threads
63
Messages
3,835
Reaction score
4,806
Location
SE MI
Vehicles
'22 Lighting ER Lariat,'22 Mach-E Premium 4X
I won't downplay the issues that some have had. But this is like 1% or less of cars sold to customers. And, as noted, it seems to be mostly earlier builds. We never had it on our May 2021 build.
 

Mike G

Well-known member
First Name
Mike
Joined
Jan 6, 2022
Threads
16
Messages
981
Reaction score
1,157
Location
N. AL, USA
Vehicles
2022 F-150 Lightning, 2023 Mach-E GT-PE
Yeah, me neither. I have an early '21 build and have never had that problem. I also haven't had the HVJB or halfshaft problems I see on the forum either.
 

Maquis

Well-known member
First Name
Dave
Joined
May 20, 2021
Threads
8
Messages
2,869
Reaction score
3,478
Location
Illinois
Vehicles
2021 Mach-E E4-X; 2023 Lightning Lariat ER
Yeah, me neither. I have an early '21 build and have never had that problem. I also haven't had the HVJB or halfshaft problems I see on the forum either.
👍🏼
People with problems tend to flock to these forums to share information and discuss possible solutions. That’s fine!
We just need to keep in mind that thousands of owners without issues don’t bother to post about it on the forums. It’s just human nature.
 

Theo1000

Well-known member
First Name
Theo
Joined
May 19, 2021
Threads
1
Messages
189
Reaction score
154
Location
Shawnee, KS
Vehicles
Audi Etron,Chevy Volt,BMW I3,Mach-E,F150 Lightning
Have a Mach-E never had an issue w/ the 12v. I think it was just first couple months and was a software charge issue of not transferring power from the HV to LV batteries. It was fixed very quickly.
 
Last edited:

EdRudy

Well-known member
First Name
Ed
Joined
Sep 6, 2022
Threads
1
Messages
223
Reaction score
270
Location
Springfield, VA.
Vehicles
2022 F150 Lariat Lightning ER Iced Blue Silver
Occupation
IT
I was sitting here scratching my head trying to figure out what MME stood for before I suddenly realized its

Mustang Mach E.

Still working on HVJB... I'm thinking High Voltage Junction Box but who knows...
Sponsored

 


 


Top