Picked up my 2015 85D a couple days ago that had the daughterboard replaced with the
MSX MCU TEGRA VCM REV-A-PROVISION (64GB) (2728212-S0-A) under the 4 year/50k mile warranty (purchased the car used through Tesla about two years ago).
A couple months ago, my mobile app stopped connecting to my car. Didn’t think much of it and the issue persisted for about a month until one night I started to troubleshoot. After attempting a couple MCU reboots, the center screen just stayed black and it appeared the MCU would not boot up. I had pin to drive enabled so the car was pretty much a brick and I had to get it towed to Tesla. They diagnosed the car and said the SD card that holds the map data was corrupt, so they formatted the SD card and performed a factory reset and everything was working again.
A couple weeks later, the mobile app stopped connecting to my car again. I gave it a week, tried some of my own troubleshooting to include an MCU reboot but it still would not connect. Before attempting to log out of the mobile app and back in, I went ahead and made a service appointment because I learned from last time that if your mobile app can’t connect to your car, you can’t make service appointment via the app which is a pretty poor design in my opinion. I realize you can call the service center, but the one here never answers.
Initially they scheduled me for a mobile technician to come out to troubleshoot the issue, but a few days later it was changed to an appointment at the service center and they put the Tegra daughterboard on order. The latest email I received from Tesla said the daughterboard was still “pending” for shipping, so I left a message with Tesla and they called me back the next day to confirm they still haven’t received the part and that I could drop it off on Friday when they were hoping to expect the part. Dropped off the car and a few days later, they were finished and ended up replacing the daughterboard. Of note, I received an email after I dropped off the car with the status of the daughterboard and it still said “pending” (never actually got an email saying it actually shipped), but they apparently received it.
It’s only been a few days but everything seems to work fine. I did notice in the description of work on the invoice, they mentioned the touchscreen was blank so they replaced the MCU Tegra daughterboard per a service bulletin. When I dropped off the car, the screen was working fine so the eMMC must have died between dropping it off and when they looked at it - lucky on timing I guess. I did notice in the notifications section on the center display, there were several errors of the touchscreen being unresponsive while it was in service.
