I'm attempting to update our '18 TourX Essence to 21.11 (or .10), using a FAT32-formatted USB drive. I've extracted the update files into the root directory of the USB, but am getting the error message "Vehicle update download failed." upon insert of the USB. Have tried with both x.11 and x.10 with the same result.
FWIW, I've done similar updates on my other vehicles, so I'm not new to the process, but could also be missing something obvious.
I didn't see this anywhere in this whole thread, but it seems the car must either be running, or have the ignition "ON" (not running, not in ACC) for the update process to start. I do have a battery jump-pack connected (not plugged in).
Don't know if it matters, but we have never activated OnStar on this vehicle (since new).
Any suggestions?