@ghoststl The updates are huge (hundreds of MB), so I wouldn’t expect OnStar to be able to download them to the vehicle. What’s more than likely to happen is that Chevy will provide the update for download on its website. From there, you can put the update on a USB drive, plug the drive into the USB port in the car, and MyLink will update from there.
Other than that, I’m sure the dealer will be able to install the update as well.
