12v battery need to be replaced?

[Jd43325]

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!

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[Mach-Lee]

50-60% health is time to replace, especially if you are getting odd faults. So I definitely would. They should have told you that was marginal, not good.

 

[Jd43325]

50-60% health is time to replace, especially if you are getting odd faults. So I definitely would. They should have told you that was marginal, not good.

Thank you!!

 

[Aboltoflightning!]

50-60% health is time to replace, especially if you are getting odd faults. So I definitely would. They should have told you that was marginal, not good.

@Mach-Lee is there a way to know the health of the 12V through an OBD and car scanner? (like what was posted above with the 61% example) and if so, which sensor or line item would indicate that? or would I need to bring it in and have them test it for me?

Thanks for taking the time to respond

 

[dtbaker61]

@Mach-Lee is there a way to know the health of the 12V through an OBD and car scanner? (like what was posted above with the 61% example) and if so, which sensor or line item would indicate that? or would I need to bring it in and have them test it for me?

Thanks for taking the time to respond

there is no way I am aware of to measure "remaining capacity" or Health of the 12v battery via ODB2 sensor data I am aware of.

It is a lot harder to measure than "cold cranking power" we are used to checking with 12v batteries intended to start ICE motors.

The consequences of a failed 12v in the MME are unpleasant, unpredictable, and sudden. If the battery is less than 36 months old and questionable, try for replacement under warranty. If it is over 36 months, just replace it now.

 

[Aboltoflightning!]

there is no way I am aware of to measure "remaining capacity" or Health of the 12v battery via ODB2 sensor data I am aware of.

It is a lot harder to measure than "cold cranking power" we are used to checking with 12v batteries intended to start ICE motors.

The consequences of a failed 12v in the MME are unpleasant, unpredictable, and sudden. If the battery is less than 36 months old and questionable, try for replacement under warranty. If it is over 36 months, just replace it now.

Thanks, that's what I figured but I thought I would confirm with more knowledgeable people of this forum as I am not one of those. Thanks for replying.

 

[Mach-Lee]

@Mach-Lee is there a way to know the health of the 12V through an OBD and car scanner? (like what was posted above with the 61% example) and if so, which sensor or line item would indicate that? or would I need to bring it in and have them test it for me?

Thanks for taking the time to respond

No.

 

[Adventureboy]

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?

Yes. 12V issues are a pain. Replace it - it is cheap. It is especially important if you drive less than 60 miles per day or don't drive for 2-3 days at time since this draws down the 12v battery regularly.

 

[Eagertrader]

Replace if it is close to 3 years. Mine died without ever giving me a single warning one week before the third year.

 

[bellyer]

So, having a MME First Edition that I bought in March 2021, is it safe to assume that I should contact my dealer and ask that they replace the 12v battery at this point? I've been wondering about this lately. I have not had any issues with the vehicle, but I certainly don't want my wife or me to end up stranded somewhere in the middle of winter here in Chicago.

 

[dtbaker61]

So, having a MME First Edition that I bought in March 2021, is it safe to assume that I should contact my dealer and ask that they replace the 12v battery at this point? I've been wondering about this lately. I have not had any issues with the vehicle, but I certainly don't want my wife or me to end up stranded somewhere in the middle of winter here in Chicago.

yes, you are living on borrowed time.... have it replaced asap.

 

[Maquis]

So, having a MME First Edition that I bought in March 2021, is it safe to assume that I should contact my dealer and ask that they replace the 12v battery at this point? I've been wondering about this lately. I have not had any issues with the vehicle, but I certainly don't want my wife or me to end up stranded somewhere in the middle of winter here in Chicago.

My car is a month older than yours. My 12V battery failed without any prior symptoms on January 1st. Fortunately, I had just parked in my garage. If you can’t tolerate a sudden failure, replaced it now.

 

[Adventureboy]

So, having a MME First Edition that I bought in March 2021, is it safe to assume that I should contact my dealer and ask that they replace the 12v battery at this point? I've been wondering about this lately. I have not had any issues with the vehicle, but I certainly don't want my wife or me to end up stranded somewhere in the middle of winter here in Chicago.

That is a long time for a battery in our MMEs. I might be tempted to see just how long it will go, although that won't give you peace of mind . It will likely give you warning messages if it is getting weak like "Plug in to maintain 12v Battery" or something similar. I can also show up as more frequent problems with FordPass functions like remote climate control that require the modem since the car will shut the modem down if it draws down the 12v battery too far. That said, folks above have had no warnings at all.

If you have a maintenance appointment, the dealer can test it. If not, I'd probably replace it to keep it fresh. A dead 12v battery can wreck your day.

 

[pcvtre]

So my MME had the same message, but I did not check this forum to replace the battery. It happened three separate times and it will no longer start. It is currently stranded under the place where I work out at with a 10 foot ceiling. I tried jump starting it for 30 mins. I then changed out the battery and did a BMS reset but still the same message, AWD Off, Service Vehicle Soon, Hill Start Assist N/A, Pre-Collision Assist N/A, 1-Pedal Driving Fault, Service Advancetrac. Any suggestions on what to do next?

 

[vel0city]

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 AWD 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?

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