How did you figure out that the heater was bad?
Very good question!
They actually haven't given me an explanation yet. Another problem is that the staff sometimes have no clue about it. Well, during the last year, when I supercharged the power started much lower, it also declined faster, which is also what I read here on this forum. As a result, it took 2 hours and a half to charge from 10% to 90%. Has been passed on to Tesla Assistance several times to annoying. You just had to know how much time it takes you to explain this too, with the lengthy queue times ... while most operators are clueless. Finally, after almost a year and an explicit insistence from me, they made an appointment for a service visit.
But they wanted to investgate remotely, they still wanted some more information, and I had to provide them with data such as times, percentages, etc. However I had previously passed that data to the Tesla Assistance several times over several charges over months. This way you will find out that they actually do nothing with it. Besides, the service advisor from the Service Center in the area said they can only look back eight days. Do you have to take this seriously?( after all those calls, should have had a smartphone that registered them ... ) After a few seconds I understand from that man that he is not technically skilled ... . Because he came up with a number of things, the first was that the AC DC ratio was not favorable and therefore the supercharging was smothered. No fun, if you want to make a trip of 600-700 miles. With this change I would have to count an extra day for this trip compared to normal supercharging. The development of the charging capacity had also changed according to an update from Tesla sometime in early 2019. I was particularly perplexed by that AC DC ratio, actually discriminating and never informed before, the way they want to determine the use of your car. I still have a another, company car that I use every day for work and the Model S is more of a pleasure car to go on holiday or discover.
Many times I tried to point out that it could be something with the temperature management.
After I called him to ask what the investigation revealed he kept insisting that everything is normal, checked, "and pay attention, sir, if you want to come to the service center anyway, if our people don't find anything, you pay all the hours they would have spent."
Consequently, I judged the recent interaction with Service Advisor poor. More than 3 weeks later (March 26, 2020) I suddenly get a Tesla Service Estimate in which they present the replacement of the battery heater. Then I called that guy and had to hear again an evasive explanation that the so-called from above found the defect. Not happy at all with such a statement that you can't even call it, I replied that I am fed up and I am going to file a complaint.
