Wait a minute. I'm not 100% SURE about all that. All I know is that out of the blue, the car (2020 CT5-VSeries) acted like an iPhone the other day requesting a software update to happen. I'm like WTF? So I delayed it via the touchscreen. So in order for the download to happen, you have to accept it, turn the car off, but it keeps the infotainment screen powered up and it locks the car down saying it cannot move, and no power accessories will work until the download is complete. Takes several minutes and you can go ahead and leave the car when it happens. I chose to stay and watch. It has a download progress bar and goes into minimum power mode (screen gets darker) during the download. Once it's done, it turns the power to the screen off like normal.
Now, the thing I am NOT sure of if it was simply BCM updates or if it could have been connected to the drivetrain software. I read something in the manuals about navigation map updates, I do recall an article I read on the Blackwing CT5-V development where GM would have the ability to update drivetrain or other vehicle software via OnStar which would almost make it impossible to do a performance tune unless you redesigned a lot of computerized junk. Is that here already? I dunno. Not even sure how much of that article was true anyway about drivetrain updates.
But I did find this from the CT5 information from GM...(note the last sentence in the first paragraph. Reads like a bad translation from some other language. 🙂 ) What are they not telling us?