M3 problem - dies when it is frosty.

[Helixx]

So.

I had a problem about 1 month ago. The Tesla died out of nowhere.

Got it to Tesla and got a new 12v. Worked fine for about a week. After this it died again. (Died meaning totally unresponsive).

I got another appointment after this and they had the car for about 2 weeks with the response ”tightened the 12v bolts, no problem, car now works fine”.

Got it back. About 10 days ago again - dead.

The only thing connecting these 3 times is the temperature. all three times the temperature was below 0 degrees celsius, so as soon as its frosty.

Any idea guys?

 

[Tam]

So.

I had a problem about 1 month ago. The Tesla died out of nowhere.

Got it to Tesla and got a new 12v. Worked fine for about a week. After this it died again. (Died meaning totally unresponsive).

I got another appointment after this and they had the car for about 2 weeks with the response ”tightened the 12v bolts, no problem, car now works fine”.

Got it back. About 10 days ago again - dead.

The only thing connecting these 3 times is the temperature. all three times the temperature was below 0 degrees celsius, so as soon as its frosty.

Any idea guys?

When was the car made? Did it work during 0F winters before?

 

[Helixx]

When was the car made? Did it work during 0F winters before?

It is a 2020. I got it in november. We had a few cold nights when I got it, and it worked fine whole of december. So the problems started in mid january..

 

[Tam]

It is a 2020. I got it in november. We had a few cold nights when I got it, and it worked fine whole of december. So the problems started in mid january..

That year means you got the normal 12V, not the 15.5v lithium battery.

That doesn't explain why yours run out too fast.

Sorry that I have no idea.

Please give us an update when you can.

 

[rotarypower101]

That year means you got the normal 12V, not the 15.5v lithium battery.

That doesn't explain why yours run out too fast.

Sorry that I have no idea.

Please give us an update when you can.

Anyone know, do any variations of the lithium 16V LV cells have issues in the "extreme" cold over long periods of inactivity and cold soaked?

Is there any issue with the 16V LV cells not charging if they cannot create enough warmth and charging back up when the PCS turns on?

Is that possibly a reason why they did Not use LFP LV packs keeping the nominal voltage ~12Vdc?

 

[Flybyglass]

The current Ohmmu for model 3 is heated and works at low temperatures however, if your 12 volts dies after a week twice there is something else. I would access the service mode and see what messages are present to help point to the cause. In service mode, you can view the LV system to see if any components are flagged. To enter service mode, in PARK on the software page press and HOLD on the model car (there is an invisible button there). After about 5 seconds release and a popup box asks for password. it is service (all lower case). Accept the disclaimers. When in service mode (red bordered) you can select service messages see what is said. Take a photo and you can expand each for more detail. Then select the LV page (left margin) and view the low voltage charging system. The car should not keep diving in cold weather. Assuming your main battery was charged it will wake and recharge the LV battery as needed. If you can park with the charging cable connected that helps as well to precondition before departure.

 

[ewoodrick]

Anyone know, do any variations of the lithium 16V LV cells have issues in the "extreme" cold over long periods of inactivity and cold soaked?

Is there any issue with the 16V LV cells not charging if they cannot create enough warmth and charging back up when the PCS turns on?

Is that possibly a reason why they did Not use LFP LV packs keeping the nominal voltage ~12Vdc?

ANY battery has issues in cold.

 

[ewoodrick]

So.

I had a problem about 1 month ago. The Tesla died out of nowhere.

Got it to Tesla and got a new 12v. Worked fine for about a week. After this it died again. (Died meaning totally unresponsive).

I got another appointment after this and they had the car for about 2 weeks with the response ”tightened the 12v bolts, no problem, car now works fine”.

Got it back. About 10 days ago again - dead.

The only thing connecting these 3 times is the temperature. all three times the temperature was below 0 degrees celsius, so as soon as its frosty.

Any idea guys?

What is the charge level of the main battery when parked? Was it plugged in?

 

[KenC]

Is this a PCS problem? The car's HV not keeping the 12v properly charged?

 

[rotarypower101]

ANY battery has issues in cold.

The underlying question being at low temperatures, if the 16V lithium LV pack can not be heated sufficiently, will the packs BMS deny power flow to charge the cells ever? Is that possibly why there have been some issues documented in social media with LV systems in the cold recently, and specifically after sitting unused for a period of time?

And to extend the question, LFP seems to have even greater issues with charging at low temperatures, might that be why Tesla chose to use what I assume is ternary cells in the 16V LV pack and not the LFP cells in the LV pack?

 

[ewoodrick]

The underlying question being at low temperatures, if the 16V lithium LV pack can not be heated sufficiently, will the packs BMS deny power flow to charge the cells ever? Is that possibly why there have been some issues documented in social media with LV systems in the cold recently, and specifically after sitting unused for a period of time?

And to extend the question, LFP seems to have even greater issues with charging at low temperatures, might that be why Tesla chose to use what I assume is ternary cells in the 16V LV pack and not the LFP cells in the LV pack?

Except that the OP said they have a 12V battery.

 

[ItsNotAboutTheMoney]

Is this a PCS problem? The car's HV not keeping the 12v properly charged?

Either failure to keep it charged, or there's an additional drain on the 12V.

OP, do you have any additional devices plugged in?
Are you using any special remote services?
Are all extra optional internal power uses, such as lighting, correctly off?

 

[Helixx]

Yes. Always plugged in.

No extra or third party apps like tessie..

 

[Helixx]

It starts again as soon as temperature gets hotter.. and no codes in service mode.

So right now it is working fine. When i check low voltage in service everything looks fine and volts is right..