12v battery need to be replaced?

[Maui]

I just had a 2021 Mach E have its 12V battery die. Died in a parking lot in ~40F weather stranding my family. All kinds of errors about systems not working like AWS and single pedal and what not, wouldn't actually drive. Stereo turned off automatically to preserve 12V battery. Checked the voltage on the jump points, it was down to almost 9V by the time I got there about 20 minutes after. Managed to start it off another car nearby and there were no odd codes once it turned on. Drove it home as dealerships were closed, kept it on for hours plugged in to a level 2 charger. In the morning the battery was down to ~1V. Started the car with a battery jump pack/starter, lots of error codes, no power steering, AWD failure, one pedal drive issue, etc. Drove it to the dealership.

That was over a week ago. Dealership wanted to "diagnose" the issue which apparently included attempting to recharge a 4 year old battery and reinstall it to the car, which continued to have issues. They then asked me to authorize $700 to replace the battery and cover the costs for their diagnostics labor. Absolutely absurd, managed to talk them down to ~$430 as their diagnostics were unnecessary (I came in asking for a new battery!).

Now they're saying it still has these codes P087F, U0238, U0415 and want me to pay for a lot of additional diagnostics labor. And apparently pay hundreds of dollars to "install updates". What gives?

which dealership is this? Feels like one to avoid.

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[Maquis]

I just had a 2021 Mach E have its 12V battery die. Died in a parking lot in ~40F weather stranding my family. All kinds of errors about systems not working like AWS and single pedal and what not, wouldn't actually drive. Stereo turned off automatically to preserve 12V battery. Checked the voltage on the jump points, it was down to almost 9V by the time I got there about 20 minutes after. Managed to start it off another car nearby and there were no odd codes once it turned on. Drove it home as dealerships were closed, kept it on for hours plugged in to a level 2 charger. In the morning the battery was down to ~1V. Started the car with a battery jump pack/starter, lots of error codes, no power steering, AWD failure, one pedal drive issue, etc. Drove it to the dealership.

That was over a week ago. Dealership wanted to "diagnose" the issue which apparently included attempting to recharge a 4 year old battery and reinstall it to the car, which continued to have issues. They then asked me to authorize $700 to replace the battery and cover the costs for their diagnostics labor. Absolutely absurd, managed to talk them down to ~$430 as their diagnostics were unnecessary (I came in asking for a new battery!).

Now they're saying it still has these codes P087F, U0238, U0415 and want me to pay for a lot of additional diagnostics labor. And apparently pay hundreds of dollars to "install updates". What gives?

That dealer sucks. Never go there again.

Since you’re capable of starting the car with a jump pack, you’re also capable of changing the battery yourself. But I also understand not wanting to in sub-zero temps!

 

[vel0city]

That dealer sucks. Never go there again.

Since you’re capable of starting the car with a jump pack, you’re also capable of changing the battery yourself. But I also understand not wanting to in sub-zero temps!

Not sub-zero, about forty over zero. I had contemplated changing the battery but taking the tub out or removing the cross brace seemed a bit daunting at the time so I took it in. Big mistake it seems.

As for the dealership, North Central Ford in Richardson TX (DFW area). Not the first time I've had rough experiences with them.

Any thoughts on these DTCs? Seem like the last one is just a common code that isn't really a concern. Another would suggest the stereo doesn't work which I asked, "well do you hear sound from the stereo?" and they couldn't answer that at the moment. Then one is about single-pedal driving which once again they were unsure if single-pedal was actually operational or not. None of these DTCs would imply something wrong with the HVJB from what I can tell.

I think I'm leaning towards just picking up the car with the new battery and never going back there. Should I be concerned about these DTCs though?

 

[Maquis]

Not sub-zero, about forty over zero. I had contemplated changing the battery but taking the tub out or removing the cross brace seemed a bit daunting at the time so I took it in. Big mistake it seems.

As for the dealership, North Central Ford in Richardson TX (DFW area). Not the first time I've had rough experiences with them.

Any thoughts on these DTCs? Seem like the last one is just a common code that isn't really a concern. Another would suggest the stereo doesn't work which I asked, "well do you hear sound from the stereo?" and they couldn't answer that at the moment. Then one is about single-pedal driving which once again they were unsure if single-pedal was actually operational or not. None of these DTCs would imply something wrong with the HVJB from what I can tell.

I think I'm leaning towards just picking up the car with the new battery and never going back there. Should I be concerned about these DTCs though?

Sorry…I read your tilde as a minus sign. In my defense, I had cataract surgery yesterday.

I‘ll let someone more knowledgeable than me address the trouble codes.

 

[Mach-Lee]

Now they're saying it still has these codes P087F, U0238, U0415 and want me to pay for a lot of additional diagnostics labor. And apparently pay hundreds of dollars to "install updates". What gives?

Those codes are of no concern and can be ignored as minor glitches. This dealer is just trying to empty your wallet. Replace the 12V battery yourself, it should cost about $150 or less.

 

[vel0city]

End of the work day the manager called me back and is saying the car's 12V system is dead again after another overnight with a new battery. They haven't told me any other actual codes that would relate to battery drain and seemingly haven't even tested if there is parasitic drain on the 12V with a multimeter. They once again asked for a carte blanche approval to do "diagnostics" and "updates" to solve whatever problem. I asked for actual detailed plans for me to approve and they wouldn't be able to get back to me until tomorrow.

I don't get what would be causing any drain. I haven't installed anything like a camera or otherwise tapped into the 12V system. The HV battery was down to 28% last it checked in with the app, it's been outside in below freezing temps, I imagine the state of charge of the 12V off the shelf could have been questionable. They haven't been plugging it in, or if they have it hasn't charged but didn't throw any charging errors in the Ford app. I wonder if that could result in the car being seemingly dead.

 

[Mach-Lee]

End of the work day the manager called me back and is saying the car's 12V system is dead again after another overnight with a new battery. They haven't told me any other actual codes that would relate to battery drain and seemingly haven't even tested if there is parasitic drain on the 12V with a multimeter. They once again asked for a carte blanche approval to do "diagnostics" and "updates" to solve whatever problem. I asked for actual detailed plans for me to approve and they wouldn't be able to get back to me until tomorrow.

I don't get what would be causing any drain. I haven't installed anything like a camera or otherwise tapped into the 12V system. The HV battery was down to 28% last it checked in with the app, it's been outside in below freezing temps, I imagine the state of charge of the 12V off the shelf could have been questionable. They haven't been plugging it in, or if they have it hasn't charged but didn't throw any charging errors in the Ford app. I wonder if that could result in the car being seemingly dead.

Here's a list of drain causes that may be helpful: https://www.macheforum.com/site/thr...-system-drain-service-required-message.36140/

In rare cases, you may have some kind of wire corrosion somewhere, or rodents chewing on wires that could cause a sudden 12V drain.

I can look at your VIN to see anything unusual if desired (DM me).

I really think that just putting in a brand new full charged 12V battery and resetting the BMS should do it. Make sure they reset the BMS.

 

[MonicaArmstrong]

I have a 2021 Mach-e. All these error messages happened to mine too. Stranded in extreme cold weather. Had 12v battery replaced. One month later……exact same error messages. Stranded again, awaiting diagnostics.

 

[Shayne]

Hi All,
I’ve been getting intermittent error messages (AWD Off, Service Vehicle Soon, Hill Start Assist N/A, Pre-Collision Assist N/A, 1-Pedal Driving Fault, Service Advancetrac) when starting my 2021 in temps below 20°F. I suspect the 12V battery might be the issue.

I had it tested at Advanced Auto (12.71V static, 14.64V alternator test), and they said it was “good” but recommended replacement soon. Ford tested it too, said it was “good” at 61% health, and didn’t need replacement.

Since 61% seems close to the 50% threshold that Mach-lee recommended for replacement and with winter in full swing, is it worth going against ford's recommendation replacing the battery now, or should I wait?

Thanks!

Ford does not replace them until 50% soh but the car will not install updates with it below 80%. How does that work?

 

[Mach-Lee]

Ford does not replace them until 50% soh but the car will not install updates with it below 80%. How does that work?

SoC and SoH are different. You can have a battery at 60% state of health that is charged to 90% state of charge. Which will still install OTAs.

 

[Shayne]

SoC and SoH are different. You can have a battery at 60% state of health that is charged to 90% state of charge. Which will still install OTAs.

Yes but as SOH goes down the chances of it being over 80% decreases. It is the specific gravity of a aqueous solution and is related to the maximum voltage it can charge to. At 50% soh I would say the amps it can deliver have decreased. At 50% soh it is not charging it to 100% voltage and has only 50% its original storage.

What do you think the reason is that 2021 updates are few and far between?

All this tech and battery capacity and the weak link turns out to be a little 12V. It dies kids are trapped, people are locked out or it just does not go into gear. If it is low the car will not update. Bit amazing the logic and dependency on a small 12V when there is a power supply onboard powered by a huge battery. That we should see change over time; maybe for my second one?

 

[Mach-Lee]

Yes but as SOH goes down the chances of it being over 80% decreases. It is the specific gravity of a aqueous solution and is related to the maximum voltage it can charge to. At 50% soh I would say the amps it can deliver have decreased. At 50% soh it is not charging it to 100% voltage and has only 50% its original storage.

What do you think the reason is that 2021 updates are few and far between?

All this tech and battery capacity and the weak link turns out to be a little 12V. It dies kids are trapped, people are locked out or it just does not go into gear. If it is low the car will not update. Bit amazing the logic and dependency on a small 12V when there is a power supply onboard powered by a huge battery. That we should see change over time; maybe for my second one?

The 12V battery is not the reason 2021's aren't getting OTAs. Ford isn't sending them out due to dependency and server issues. If the 12V battery was causing problems, it would say "OTA failed to install, conditions not met". The absence of OTAs does not mean the 12V battery is bad. FDRS will be required to get 2021's fully up to date.

I've seen plenty of OTAs install with marginal batteries that were down to close to 50% SoH. Different OTAs require different amounts of battery to install. If the battery won't go to 100% SoC, it will still install OTAs. The normal fully charged target is 92% on the Mach-E BMS.

And I know you disagree, but the 35 Ah AGM is plenty large for the vehicle needs. Tesla uses a 7 Ah battery, which is five times smaller than our battery for comparison. A larger battery would not have prevented the 12V issues, they were due to early abuse of the battery (e.g. vehicle was parked on dealer lot with almost dead battery for months) and poor 12V management in software (which has been improved). Damage is cumulative as active lead material is lost.

 

[Shayne]

The 12V battery is not the reason 2021's aren't getting OTAs. Ford isn't sending them out due to dependency and server issues. If the 12V battery was causing problems, it would say "OTA failed to install, conditions not met". The absence of OTAs does not mean the 12V battery is bad. FDRS will be required to get 2021's fully up to date.

I've seen plenty of OTAs install with marginal batteries that were down to close to 50% SoH. Different OTAs require different amounts of battery to install. If the battery won't go to 100% SoC, it will still install OTAs. The normal fully charged target is 92% on the Mach-E BMS.

And I know you disagree, but the 35 Ah AGM is plenty large for the vehicle needs. Tesla uses a 7 Ah battery, which is five times smaller than our battery for comparison. A larger battery would not have prevented the 12V issues, they were due to early abuse of the battery (e.g. vehicle was parked on dealer lot with almost dead battery for months) and poor 12V management in software (which has been improved). Damage is cumulative as active lead material is lost.

My last OTA said not completed or something like that with a tap for help? I put it on the high amp 12V charger and it completed. I would assume there are some OTA's that the a battery will no longer have the capacity to do at 50% capacity.

I do not disagree with you about the battery sizes. I am the guy that says all it should be is a rechargeable CMOS battery but it is not. PC motherboard CMOS battery are not rechargeable and last for awhile. One that can recharger should last a lot longer than that.

Agree my first 12V was abused with contact stuck open and was replaced. I kept the second on a charger until fixed so it was only drained once (maybe 2x?) and then maintained. Booting the entire system (all modules) off the 12V is not the best logic if you ask me. Installing OTA same thing. It was early abuse for my first one now we see if the second dies before 4 years?

 

[dbsb3233]

My last OTA said not completed or something like that with a tap for help? I put it on the high amp 12V charger and it completed.

This just happened to me. BC 1.3 failed to complete in December and I've been stuck on that ever since. Got home from a 2 week trip driving the Bronco Sport to find the MME wouldn't go into gear after 2 weeks of sitting. Thought it might be a low LVB so I yanked the cover and put it on the trickle charger. Charger said 60% but not sure how accurate that is. Later in the day it hit 100 so I disconnected and turned the car on. Still wouldn't go in gear, but after 4 months a message popped up saying BC 1.3 was ready to install. Coincidence?

So I let it install (said 140 minutes, I think). Shows complete now, but still won't go into gear. I know "complete" isn't always fully complete though, so I'll give it another day or two before worrying much. At least it's at home in the garage this time, not stuck 1000 miles from home.

 

[Shayne]

This just happened to me. BC 1.3 failed to complete in December and I've been stuck on that ever since. Got home from a 2 week trip driving the Bronco Sport to find the MME wouldn't go into gear after 2 weeks of sitting. Thought it might be a low LVB so I yanked the cover and put it on the trickle charger. Charger said 60% but not sure how accurate that is. Later in the day it hit 100 so I disconnected and turned the car on. Still wouldn't go in gear, but after 4 months a message popped up saying BC 1.3 was ready to install. Coincidence?

So I let it install (said 140 minutes, I think). Shows complete now, but still won't go into gear. I know "complete" isn't always fully complete though, so I'll give it another day or two before worrying much. At least it's at home in the garage this time, not stuck 1000 miles from home.

No errors when it boots just does not go into gear? Only time it would not go in gear for me is when the 12V was weak and it would spit lots of error messages at me as it failed to boot clean due to lack of juice. Charge it and all was good here. Can you read codes or maybe someone here can help you out.

Recommend drilling ports through the cover to hook up a 12V charger. It is not as frustrating when you need to put a charger on it. I have ports and the 12V charger in the frunk for those long trips after it stranded me once.

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