2018 Model 3 Resistive Cabin Heater not working while driving

[myers567]

So my heater finally got fixed. After waiting forever for the part, my car came up with a warning that 'Car may not restart; schedule service'. Tesla responded that it was due to the PTC heater faulting, and that if affects the high voltage loop. Sure enough, next morning, car won't go into gear, lots of messages coming up about electrical system shutting down. Schedule a tow for the Monday. Next day, go to empty out my car and it's completely dead. App won't connect, doors are locked, key card doesn't work. Go buy a 12V from Cdn Tire ($150) and pop the frunk using the cables in the tow port, replace the battery and can open the car & empty out. Install the tow hook in the frunk before locking up again. Sure enough, the next morning, the new 12V is completely dead. Tow it Tesla ($400), and two weeks later get a message it's fixed. Text (because there's no one to call) to ask if the 12V from Cdn Tire is OK and they say it looks fine. Go to pick up the next morning, and there's a 'Schedule service to replace low voltage battery' message on the screen. Go back in to 'service' where I'm told they are too busy to fix and I should take the battery back to Cdn Tire and replace under warranty. So apparently I'm replacing the 12V again this weekend, myself Unbelievably disappointed in Tesla service. Because nothing was under warranty, I'm stuck without a car without any idea when the part may come in. Had the part come in earlier (in the months that I've had no heat), I could have saved myself over $500 in tow/battery, and having to borrow cars for two weeks when the car became inoperable. So if you're heater goes, get on the list for a new one, because you may think you just have no heat, but eventually your car will die. I did look for an aftermarket/used part and couldn't find one.

 

[DocHolliday]

So my heater finally got fixed. After waiting forever for the part, my car came up with a warning that 'Car may not restart; schedule service'. Tesla responded that it was due to the PTC heater faulting, and that if affects the high voltage loop. Sure enough, next morning, car won't go into gear, lots of messages coming up about electrical system shutting down. Schedule a tow for the Monday. Next day, go to empty out my car and it's completely dead. App won't connect, doors are locked, key card doesn't work. Go buy a 12V from Cdn Tire ($150) and pop the frunk using the cables in the tow port, replace the battery and can open the car & empty out. Install the tow hook in the frunk before locking up again. Sure enough, the next morning, the new 12V is completely dead. Tow it Tesla ($400), and two weeks later get a message it's fixed. Text (because there's no one to call) to ask if the 12V from Cdn Tire is OK and they say it looks fine. Go to pick up the next morning, and there's a 'Schedule service to replace low voltage battery' message on the screen. Go back in to 'service' where I'm told they are too busy to fix and I should take the battery back to Cdn Tire and replace under warranty. So apparently I'm replacing the 12V again this weekend, myself Unbelievably disappointed in Tesla service. Because nothing was under warranty, I'm stuck without a car without any idea when the part may come in. Had the part come in earlier (in the months that I've had no heat), I could have saved myself over $500 in tow/battery, and having to borrow cars for two weeks when the car became inoperable. So if you're heater goes, get on the list for a new one, because you may think you just have no heat, but eventually your car will die. I did look for an aftermarket/used part and couldn't find one.

Wow, what a saga. Do they have any idea what killed the new 12V battery overnight?

 

[XPsionic]

So my heater finally got fixed. After waiting forever for the part, my car came up with a warning that 'Car may not restart; schedule service'. Tesla responded that it was due to the PTC heater faulting, and that if affects the high voltage loop. Sure enough, next morning, car won't go into gear, lots of messages coming up about electrical system shutting down. Schedule a tow for the Monday. Next day, go to empty out my car and it's completely dead. App won't connect, doors are locked, key card doesn't work. Go buy a 12V from Cdn Tire ($150) and pop the frunk using the cables in the tow port, replace the battery and can open the car & empty out. Install the tow hook in the frunk before locking up again. Sure enough, the next morning, the new 12V is completely dead. Tow it Tesla ($400), and two weeks later get a message it's fixed. Text (because there's no one to call) to ask if the 12V from Cdn Tire is OK and they say it looks fine. Go to pick up the next morning, and there's a 'Schedule service to replace low voltage battery' message on the screen. Go back in to 'service' where I'm told they are too busy to fix and I should take the battery back to Cdn Tire and replace under warranty. So apparently I'm replacing the 12V again this weekend, myself Unbelievably disappointed in Tesla service. Because nothing was under warranty, I'm stuck without a car without any idea when the part may come in. Had the part come in earlier (in the months that I've had no heat), I could have saved myself over $500 in tow/battery, and having to borrow cars for two weeks when the car became inoperable. So if you're heater goes, get on the list for a new one, because you may think you just have no heat, but eventually your car will die. I did look for an aftermarket/used part and couldn't find one.

That's awful service and design on Tesla's part. Sorry you had to go through all that.

 

[myers567]

Wow, what a saga. Do they have any idea what killed the new 12V battery overnight?

Just the PTC heater faulting, I guess?

 

[bbell]

Just the PTC heater faulting, I guess?

I had a fault with the PTC recently as well (2018 LR RWD), but I am still in warranty so it was no cost. In my case the car did not shut down, I would only get heat for a minute or so and then it would stop for the rest of the drive.

From what I understand the PTC heater is attached to the high voltage system. If a fault is found in the PTC that suggests a short/serious fault the car immediately disconnects the high voltage system, thus the charging of the 12V battery stops (this is similar to what happens when the pyro fuse pops).

Once the computers run the battery down that is it, the car is "dead" and needs to be boosted.

Probably this is a better design choice than leaving 400V going into a possible short circuit in the PTC heater, which I am sure would be quite exciting, especially since it is located under the dash in the passenger compartment.

In my case although Tesla didn't have a PTC in stock they wanted me to bring the car in immediately due to the risk of a shutdown. I was given a Tesla loaner until the work was done. I felt it was handled well.

I do notice there are 2 revisions of the PTC, the latest being a -I version, which is what was installed as a replacement, so perhaps this one is improved.

 

[Coopernd]

On my drive home from work last night, approx. -6ºC outside, the cabin heater was not working. The fan would work, but the air coming out was cold. Seat heaters worked.
This morning, the cabin heated while plugged in to charge overnight, and was 22ºC by the time I got in the car, but as I started driving, the air became cool, and I turned off the climate control as it was cooling the car down again.
When parked outside at work, unplugged, I started the climate control on the app, and again, the car begins to heat up.
Have scheduled a service, but first available is February 3rd. Windshield gets dicey while the car cools on my 1 hour commute. Any ideas? Tried a soft reset while I was driving last night, and that didn't do anything.

 

[Coopernd]

On my drive home from work last night, approx. -6ºC outside, the cabin heater was not working. The fan would work, but the air coming out was cold. Seat heaters worked.
This morning, the cabin heated while plugged in to charge overnight, and was 22ºC by the time I got in the car, but as I started driving, the air became cool, and I turned off the climate control as it was cooling the car down again.
When parked outside at work, unplugged, I started the climate control on the app, and again, the car begins to heat up.
Have scheduled a service, but first available is February 3rd. Windshield gets dicey while the car cools on my 1 hour commute. Any ideas? Tried a soft reset while I was driving last night, and that didn't do anything.

My 2018 Model 3 heat died this week. Booked a SC visit but it is not until next week. They said their diagnostics say it is the PTC heater and the repair estimate is > $1500. The funny thing is that the heat works when it is plugged in - to either my 220 40A charger or 110. That seems to me that the heater core is working. I wonder if this is software. The forum notes on the newer heat pump M3s talked about a vent being jammed open in the cold. The front vents I could see looked closed. Anyone have any thoughts on this? Did you get a resolution?

 

[bbell]

My 2018 Model 3 heat died this week. Booked a SC visit but it is not until next week. They said their diagnostics say it is the PTC heater and the repair estimate is > $1500. The funny thing is that the heat works when it is plugged in - to either my 220 40A charger or 110. That seems to me that the heater core is working. I wonder if this is software. The forum notes on the newer heat pump M3s talked about a vent being jammed open in the cold. The front vents I could see looked closed. Anyone have any thoughts on this? Did you get a resolution?

I can supply a data point for you, I had the PTC fail in the spring on my 2018 LR RWD. The only way I could get heat is if I set it to max heat/defrost. As soon as I set it to temperature keeping where it would need to cycle it would fail until my next drive. You might want to try MAX heat and see if you can keep heat that way.

Tesla wanted to replace it urgently since they said it could cause other problems if it fails completely with a short (since it is connected to the high voltage system). Since I was under warranty it was easy for me.

I had a co worker have the same failure a few months later but in his case the warranty was over, when he arrived at the SC he mentioned (very nicely) that mine had failed in a similar way and they waived the labour Maybe if you mention you have seen a lot of people mentioning this failure on the forums you might be able to get a similar deal.

After it was replaced I decided to replace the air filters, since I had never done it before. When I pulled the old filters out they were totally clogged with debris. This may have not helped the situation with the PTC because the airflow was so much better after the swap, so if you haven't swapped your filters have them done while the SC is doing the PTC.

Hope this helps!

 

[okolehao]

So just linking to my earlier post here last March.. My heater repair failed again and this time it was the harness. First time PTU Heater and second time was the actual wiring harness.

Tesla Model 3 2018 Heater Failed a 2nd time in 9 months

Wanted to see if anyone else has run into this and how they approached it. My Tesla Model 3 2018 Heater has failed twice. Once 9 months ago, it was a slow fade out, each day a little less heat. Sometimes no heat, then a few days of heat, then all gone. Finally took to the SC and they...

teslamotorsclub.com

 

[GrEW]

So my heater finally got fixed. After waiting forever for the part, my car came up with a warning that 'Car may not restart; schedule service'. Tesla responded that it was due to the PTC heater faulting, and that if affects the high voltage loop. Sure enough, next morning, car won't go into gear, lots of messages coming up about electrical system shutting down. Schedule a tow for the Monday. Next day, go to empty out my car and it's completely dead. App won't connect, doors are locked, key card doesn't work. Go buy a 12V from Cdn Tire ($150) and pop the frunk using the cables in the tow port, replace the battery and can open the car & empty out. Install the tow hook in the frunk before locking up again. Sure enough, the next morning, the new 12V is completely dead. Tow it Tesla ($400), and two weeks later get a message it's fixed. Text (because there's no one to call) to ask if the 12V from Cdn Tire is OK and they say it looks fine. Go to pick up the next morning, and there's a 'Schedule service to replace low voltage battery' message on the screen. Go back in to 'service' where I'm told they are too busy to fix and I should take the battery back to Cdn Tire and replace under warranty. So apparently I'm replacing the 12V again this weekend, myself Unbelievably disappointed in Tesla service. Because nothing was under warranty, I'm stuck without a car without any idea when the part may come in. Had the part come in earlier (in the months that I've had no heat), I could have saved myself over $500 in tow/battery, and having to borrow cars for two weeks when the car became inoperable. So if you're heater goes, get on the list for a new one, because you may think you just have no heat, but eventually your car will die. I did look for an aftermarket/used part and couldn't find one.

My son’s 2018 M3 dual motor/LR had the exact same experience last week. Car no longer moving when arriving at place of work, error code alerts, etc.; had to push into a parking spot. (He had noticed a couple short periods of no heat in the car in the prior week). Next day; 12v battery dead. New 12v battery (group 51R,$176 CAD +tax, fyi) from CTC dead the morning after replacing original. Recharged it & kept on charger until CAA tow to SC. Service advisor said they would take care of the car (i.e., not necessary to disconnect 12v to keep from discharging while it sat 3 days until service appointment). They did not; they replaced again-dead CTC battery with another new Tesla one ($105+ labour & tax). After complaining about that, we got CTC battery back and I was able to fully recharge & return for refund (battery has to be ‘as new’ & resaleable condition, not installed/used, so cleaned up posts, and plastic caps, etc. reinstalled). CTC tested battery condition OK so got refund OK.

Tesla SC removed the charge for new Tesla 12v after my complaint of situation.

New PTC heater $695 CAD + 1 hr labour diagnostic charge + 1 hr labour to replace heater (2x$210CAD) + tax = approx $1200 CAD. Got the old heater back for my inspection.
As described above, this type fault causes an electrical short circuit which the software categorizes as a safety hazard so shuts down the HV system & makes car immovable. It also directly drains the 12v battery.
My other son’s 2018 M3/SR had no heat for 3 weeks last winter, but no error codes/alerts, and car was still otherwise normal/driveable. He also had to have PTC heater replaced at same cost. So his failure in PTC was just no heat.
So, 2 types of failures of these 2018 PTCs in our family experience. Both cases reported to Transport Canada for their potential future action.