Mine were completed in about 6 hours, but I've hard that some cars take much longer and that the firmware issue that you're seeing does exist.question for those of you who have already had the MCU2 upgrade done - did anyone's upgrade take more than a day for Tesla to complete?
brought my AP1 70D into service for the MCU2 infotainment upgrade first thing yesterday am - apparently hardware installation went fine but they ran into trouble updating the firmware (I was warned at drop off time they've run into that sort of problem before with other MCU2 upgrades). So they kept the car overnight aiming for completion by end of today. But now late day2 they're still having problems and need to keep the car a 2nd night, hopefully finished tomorrow. Apparently the firmware update takes several hours but then quits/fails and they have to start over; as mentioned they said they've seen this before
is a common issue with the MCU2 upgrade?
One advise is when you pick up your car, don't leave the service center until you verify all if good. Test out the Mobile App to confirm that you can unlock the car, open the hatch, vent the windows, modify the radio settings, etc...
It's a known issues, where they sometimes forgot to re-instal your security certificate which then limits your ability to use certain feature of the app. they can fix this right away. If you realize this after the fact, if you open up a service ticket in the Mobile App, they can even reset your certificate remotely if you have an internet connection to your Car (either Wifi or LTE).