Hi, I had a similar experience. The first time, model 3 was about a month old and tesla replaced the 12v and said I should be fine. When I got the same error msg 2 weeks later, I called roadside assistance who said I just needed to drive the car more (I drive it everyday) and 12v would recharge itself. I decided to drive it to the service center. After I got there it died and they couldn't get it started. They need to replace the rear drive shaft. Curious how your issue was remedied and if you've experienced any other issues? I too am excited to get my car back, but also anxious, hoping that 4 visits to the service center in 2 months is all I'll have to make for the year.