12V fault service soon message

[Benjamin Kegele]

When I search here in the forum I see a lot of results. Most of them with several cross links. But never a clear answer.

If my car parks over night and I come in the morning to it. For a split second the screen behind the steering wheel shoes sometimes a fault which says 12V fault Service soon.

It does not come always and it clears itself right away as soon the door open message comes. I feel like it comes more often, if I have not charged the night before.

It does not come during the day.

And again it does not come always.

I have a cheap multimeter and the 12V measures 12.53V when unplugged ignition off.

I do not really want to bring it i , as I see no codes in fordpass and have no proof that I actually had this code.

my car is a 2021 sr rwd delivered in 02/21 built 12/20
I have ota 2.8.3 and I had the custpmer satisfaction update installed most recently at the dealer.

@DevSecOps ran my vin and only found attached open updates. Thanks for that!

What causes this fault and what is the fix?

 

[generaltso]

It’s just a poorly worded message that pops up any time the DC/DC converter kicks on to top off the LVB while parked. If you only get it occasionally, you can ignore it.

 

[Gimme_my_MME]

It’s just a poorly worded message that pops up any time the DC/DC converter kicks on to top off the LVB while parked.

Not exactly. It is a message stating the HVB has topped up the LVB and I'm sure it could be worded better but at some point while off the LVB SoC got to a point that required a boost.

@Benjamin Kegele when did you start noticing this?

At this point it is probably not worth your time to take it to a dealer. The battery system is working properly in that it is monitoring SoC and making sure it doesn't get too low.

 

[Benjamin Kegele]

Not exactly. It is a message stating the HVB has topped up the LVB and I'm sure it could be worded better but at some point while off the LVB SoC got to a point that required a boost.

@Benjamin Kegele when did you start noticing this?

At this point it is probably not worth your time to take it to a dealer. The battery system is working properly in that it is monitoring SoC and making sure it doesn't get too low.

Someone in fb told me his car got bricked after a while.


I recently travlled for two weeks. While I was out my wife drove the car. She is not sure if she had the code. I came back 5/23 and I have it now since and probably 3-4 out 5 times in the morning when I hop in. Not when I go for lunch, not when I drive home from work. I work 8-5

 

[generaltso]

Not exactly. It is a message stating the HVB has topped up the LVB and I'm sure it could be worded better but at some point while off the LVB SoC got to a point that required a boost.

Isn't that kinda what I said?

I think the warning verbiage is a lot worse than "could be worded better". It says "12V battery fault - Service soon". But it doesn't usually indicate a fault with the 12V battery, and if you try to bring it in for service, the dealer won't be able to find any codes to diagnose. If it's working as designed, I don't think it should alert the driver at all. But if it's going to, it should say something like "12V battery low - Energy transferred from HVB". I bet this warning has resulted in a lot of unneeded service visits.

 

[Mach-Lee]

Yes, the message means the 12V was recharged while the car was off, which is normal if it happens occasionally, but it shouldn't be happening daily.

If you have hardwired accessories like a dashcam that could be the cause. Or if you do a lot of in and out after you park it might drain the battery some. Using a 3rd party app/widget to check on vehicle status may also drain the 12V.

You should know that the 12V battery is only being charged when the ignition is on (solid green light on the button). If you are in acc mode (blinking light) the 12V battery is being drained. The modes work like an ICE vehicle.

My battery is in good shape and runs around 12.7V or higher when off. You have to wait 30 minutes after opening the hood without disturbing the car before all the modules shut down so you can get a true voltage reading.

If you're still worried put a battery charger on it for a couple days like I talk about in my reconditioning topic.

 

[Logal727]

Am I the only one who has never seen this message?

The only battery message I’ve seen is the”Deep Sleep” one, yes actual deep sleep, I know about normal sleep.

 

[Mach-Lee]

And Ben looking at your topics I'm pretty sure your battery problems are caused by you having your dashcam tied into fuse #4 under the dash which is always-on power. You need to use a different fuse that is switched power so you're not draining the 12V battery.

The Recurrent health monitoring could also be suspect if it is polling the vehicle excessively though the API.

 

[Benjamin Kegele]

And Ben looking at your topics I'm pretty sure your battery problems are caused by you having your dashcam tied into fuse #4 under the dash which is always-on power. You need to use a different fuse that is switched power so you're not draining the 12V battery.

The Recurrent health monitoring could also be suspect if it is polling the vehicle excessively though the API.

I moved the dashcam long time ago to a switched fuse.
Maybe it has something to do with the recurrent software which keeps reading out data from the modem?

Can you send me a link to your recondition topic you earlier mentioned

 

[generaltso]

Am I the only one who has never seen this message?

Do you usual plug in your car when parked? If so, you aren’t likely to ever see this message.

 

[Mach-Lee]

I moved the dashcam long time ago to a switched fuse.
Maybe it has something to do with the recurrent software which keeps reading out data from the modem?

Can you send me a link to your recondition topic you earlier mentioned

Might want to double check the fuse is shutting off to be safe.

https://www.macheforum.com/site/threads/how-to-recondition-service-your-12v-battery.11069/

 

[Benjamin Kegele]

Might want to double check the fuse is shutting off to be safe.

https://www.macheforum.com/site/threads/how-to-recondition-service-your-12v-battery.11069/

thank you for sharing the link.


my dashcam turns off everytime when I press the ignition button. and I measured it before plugging it in. honestly, I do not remember the fuse number as it has been a while since. But, it always shuts off. also the recordings are only from driving. Many times my dashcam does not even come on automatically and I have to turn it on manually.

 

[Logal727]

Do you usual plug in your car when parked? If so, you aren’t likely to ever see this message.

Yeah, most I’ve gone is maybe 3 days without

 

[scoopman]

I would follow Mach-Lee's one-time battery reconditioning instructions (you can search to find that thread). It's not normal to have this occur frequently, because it means that for some reason, your 12V didn't hold enough of a charge while the car was off.

If you can attribute the battery drain to some behavior or instance (for example, a dashcam running while your car is off, or and OBD-II reader left in the car, or keeping the key or phone so nearby so that the car keeps waking up to "welcome" you) then you can safely ignore this and modify your behavior.

But if there's nothing that changed and you keep seeing this -- and if you recondition your battery and still see this -- it might be time for a dealer visit and new 12V battery.

I put a BT battery monitor on my 12V via an add-a-fuse. It's been cool to reassure me that this part of my car keeps healthy. Link to what I used to monitor my 12V from the comfort of my couch: https://www.amazon.com/gp/product/B07NSTQCM8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[Benjamin Kegele]

I would follow Mach-Lee's one-time battery reconditioning instructions (you can search to find that thread). It's not normal to have this occur frequently, because it means that for some reason, your 12V didn't hold enough of a charge while the car was off.

If you can attribute the battery drain to some behavior or instance (for example, a dashcam running while your car is off, or and OBD-II reader left in the car, or keeping the key or phone so nearby so that the car keeps waking up to "welcome" you) then you can safely ignore this and modify your behavior.

But if there's nothing that changed and you keep seeing this -- and if you recondition your battery and still see this -- it might be time for a dealer visit and new 12V battery.

I put a BT battery monitor on my 12V via an add-a-fuse. It's been cool to reassure me that this part of my car keeps healthy. Link to what I used to monitor my 12V from the comfort of my couch: https://www.amazon.com/gp/product/B07NSTQCM8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

thanks, good advice, I wonder if there is a difference on AGM batteries or if it is the same battery monitor I can use.

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