Coldest day of 2024, heater stopped working.

[Biscuitman]

I am having some gremlins going on with my pre heat pump 20 M3.
Earlier in tye month horn stoped working and then started working again after I made an appointment with SC which I cancelled.
Today the heater was blowing cold air, despite being cranked up to 25!
I was wearing my hat and gloves with the heat seater helping out. Any thoughts?

 

[richyrich]

Did you check alerts in service mode?

 

[Biscuitman]

Good point, just checked it and it said no active alerts but it did say earlier Unable to Charge. , service required .

 

[ItsNotAboutTheMoney]

Weird issues Question 1: How old is your 12V battery?

 

[Biscuitman]

I have not changed it so 4 years old

 

[Biscuitman]

 

[Tz00]

Did you try turning the temperature setpoint to Max or turn on the Red Defrost mode? Either one will ignore the actual cabin ambient temperature reading. If one of the ambient temperature sensors is bad, it can think the cabin is too hot and then try to cool it. I had this issue once on my 2019 3.

 

[Biscuitman]

Yes turned to defrost and that seemed to work fine. Tech called me this morning and said they did an OTA work around that should solve the problem , if not they will need to order a battery part that is not covered by warranty and is 1300 dollars.
Prefer to not go that route

 

[Thp3]

Four years with a TESLA 12v is a long time. Get Tesla to install a new one ( can be done by mobile ranger). Unless you have a lithium battery? Those *might* last Abit longer… Lead Acid 12V only cost about $100, lithium might be $400?

I replace my 12V every three years since is a b+*#h to fix it when it dies, often without warning.

 

[bolero]

Yah. I got my Model 3 lead acid battery replaced when the card was 4 year old. also cold weather is a 12 volt battery killer when it's old.

 

[Soul Surfer]

I’m assuming that you park outdoors? If yes, then your 12V is a remarkable battery. The cold affects/kills lots of things.

 

[brulaz]

I park my truck and trailer near Huntsville ON, but keep a 12V "battery maintainer " on them as they're not used that frequently. The batteries have typicaly lasted ~8 years when maintained that way.

So I'm surprised the Tesla hi voltage battery doesn't do a better job as a 12V "battery maintainer ", even when the system "sleeps".

 

[Thp3]

A car 12 v battery has about 1.3 kwh. A Tesla 12v car battery has about 0.4 kwh. One could guess that the Tesla battery could wear out three times faster than a car battery, very rough guess.

But in 2021 lithium 12V batteries started being used. These have a different recharge schedule than the older 12v lead acid ones. They are not swap-able. OHMU has a lithium replacement for the 12 v but some have reported issues with recharge schedules in the Tesla.

For the older Model 3s and older Model 4S it’s pretty simple and inexpensive to just replace them after about three years.

 

[Biscuitman]

I am going in to the service center tomorrow as the heat is still an issue.
They are thinking at this point that I need a “new heater” rough estimate of $1300.
I will ask them to replace the 12V at tye same time. A lot of discussion ai have seen as to why this part of the battery is not covered on the 8 year warranty. We will see soon

 

[Biscuitman]

Update: the heater element was replaced and they told me that the 12V battery is fine and if it was not the system would send me notifications. The tech told me his M3 is 6 years old and still on the original 12V, so I guess every case is different.

 

[Soul Surfer]

Update: the heater element was replaced and they told me that the 12V battery is fine and if it was not the system would send me notifications. The tech told me his M3 is 6 years old and still on the original 12V, so I guess every case is different.

Hoping this was done under warranty?

 

[Biscuitman]

Unfortunately no

 

[Runner]

I'm sorry to say that my car has had the entire cooling and heating system (coolant and battery heating related) replaced. I've spent a small used car price on fixing these. Tesla has changed a lot since I bought my first car from them, all in the negative direction though :-(

 

[ZooSean]

Update: the heater element was replaced and they told me that the 12V battery is fine and if it was not the system would send me notifications. The tech told me his M3 is 6 years old and still on the original 12V, so I guess every case is different.

How much that costs you? I think you are out of warranty already?

 

[Biscuitman]

Yes out of warranty. 1100 .