21 Select Dead, Frunk Won't Open With External 12v

[SonicBlue]

PSA: We‘re see about 2 threads per day of 2021s with failing 12V batteries. If you own a 2021 with the original battery, replace it.

And if you encounter low battery issues, pop your frunk while you still can.

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[PA27]

Similar issues this morning. Car was plugged in last night for cold north Alabama temperatures. App told me at departure time the vehicle has charged to 70% as expected and cabin temperature was ready and battery conditioned for departure. Except when I got in, cabin cold all the lights you saw and HVB was not at 70%, etc. I left doors unlocked and waiting for warmer temperatures today then I will go disconnect 12v for a few minutes to see if it resets as the app still shows no warnings.

After temperatures were above freezing, went out and tried the car, no indication I had ever had warning lights and HVB showed 69% agreeing with the app and clearly having charged last night. Pulled out frunk and disconnected 12v. Put it on the trickle charge at 2amp and it was fully charged in about an hour. Put a tester on it and it tested well as you would expect an 18 month old battery. Charged it up, closed it up and drove around the block and plugged car in again for tonight’s freezing temps. We’ll see what happens tomorrow when it prepares for departure

 

[Flyboy]

Don't lock your doors!

 

[PA27]

Don't lock your doors!

Purposely left them unlocked after reading the post on it, very helpful info I do not see in the owner’s manual. My 12 volt was just fine so no clue what caused mine. Waiting to see if the car prepares correctly for this morning’s scheduled departure.

 

[flapjake314]

Purposely left them unlocked after reading the post on it, very helpful info I do not see in the owner’s manual. My 12 volt was just fine so no clue what caused mine. Waiting to see if the car prepares correctly for this morning’s scheduled departure.

sorry does this help / why does it help? it still needs power to unlatch the doors right, or are you leaving all your doors ajar everyday? (is it not easier to just leave windows down, if you're in a garage)

also i have an obd reader, is there some way to assess 12V battery health? i see everyone just shouting to replace the battery every 3 years but it just doesn't seem like a reasonable approach to blindly replace.

out of the people on this forum and fb that had 12V's go bad, i'd say easily 50-75% were before the exact 3Y mark. i'd say maybe 25-33% were less than the 2Y mark. so are people going to throw away a 12V every 2.5 years, it just doesn't make sense....

 

[Snakebitten]

Actually, it does kinda make sense if someone doesn't have any method to monitor or verify the health of the battery, yet they don't want to risk experiencing the issues of the battery failing at a really inconvenient place/time.

I happen to be nerdy enough to monitor, even log the battery voltage, 24/7. But many folks just want to be on the safe side and a fresh battery every 3 years isn't a big deal to them.

 

[flapjake314]

I happen to be nerdy enough to monitor, even log the battery voltage, 24/7. But many folks just want to be on the safe side and a fresh battery every 3 years isn't a big deal to them.

but do you agree 3Y exactly doesn't even get them that safe? OP of this post didn't even reach 3Y for example, out of maybe 15 cases i've read so far only a couple were actually past 3Y (not even sure that's true, sometimes people just said out of warranty which could have been mileage)

there's no reason for the cautious person who is willing to spend some $ to avoid pain to look at this and say 3Y is the answer, if i was scared by these posts and wanted to be safe i'd be looking for replacement after 2Y...

 

[PA27]

sorry does this help / why does it help? it still needs power to unlatch the doors right, or are you leaving all your doors ajar everyday? (is it not easier to just leave windows down, if you're in a garage)

also i have an obd reader, is there some way to assess 12V battery health? i see everyone just shouting to replace the battery every 3 years but it just doesn't seem like a reasonable approach to blindly replace.

out of the people on this forum and fb that had 12V's go bad, i'd say easily 50-75% were before the exact 3Y mark. i'd say maybe 25-33% were less than the 2Y mark. so are people going to throw away a 12V every 2.5 years, it just doesn't make sense....

Turns out no, if unlocked and no power you can double push the button and the capacitor holds enough power to open the door. Plunger does not function and you cannot unlock the door without power but you can open an unlocked door.

 

[flapjake314]

Turns out no, if unlocked and no power you can double push the button and the capacitor holds enough power to open the door. Plunger does not function and you cannot unlock the door without power but you can open an unlocked door.

thanks didn't know that. i'm past 3Y so maybe i should start doing this... i'm in a private garage (shared with other residents, but locked from public) but leave nothing in my car (other than dash cam i guess) so probably very doable for me...

 

[flapjake314]

Actually, it does kinda make sense if someone doesn't have any method to monitor or verify the health of the battery, yet they don't want to risk experiencing the issues of the battery failing at a really inconvenient place/time.

I happen to be nerdy enough to monitor, even log the battery voltage, 24/7. But many folks just want to be on the safe side and a fresh battery every 3 years isn't a big deal to them.

https://www.macheforum.com/site/thr...erent-i-dont-have-a-garage.42305/#post-909441

new battery example by the way... again i'm not saying swapping doesn't decrease the risk it just doesn't seem like the answer is really 3Y if we go by these stories, and changing it much more often than that feels very cost/effort/waste prohibitive

 

[Flyboy]

I would also suggest you test the Frunk Soft Button. If this doesn’t open it, a dead battery becomes a much bigger problem.

 

[ricksta6]

Update:

Finally got it towed yesterday. Tow guy was able to pop the hood and confirmed 12v was totally dead.

Dealer diagnosed it and besides the 12v, the HVB connectors have apparently gone bad. Not entirely sure what connectors they’re referring to, but said it’s all covered under the 100k battery warranty so at least not paying any of this outta pocket.

They expect it’ll be ready on Monday and will try to get me a courtesy vehicle tomorrow, but not holding out hope on that.

 

[ricksta6]

Picked it up. Docs reference TSB 24-2163. Haven’t been able to find much on it but looks like they replaced the LVB and HVBJB and did a few updates.

 

[Mach-Lee]

Picked it up. Docs reference TSB 24-2163. Haven’t been able to find much on it but looks like they replaced the LVB and HVBJB and did a few updates.

That means your HVBJB was bad and prevented the 12V from being charged, hence why it died.

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