First of all, big thanks to OP for this forum post. I bough a 2011 GMC Sierra with a AVIC-X850BT and the old maps/firmware. Followed the steps and update successful. It did take the whole 45mins. After the initial 79 files updated, truck was on, I had to pull out and re-insert SD card for the hard update to initiate. Then the 45min warning came up. Thanks alot...paypal donation sent!
Step 1: Format an 8gb SD card to FAT32. Google it.
Step 2: Download the file, and extract using winrar.
Step 3: Transfer the files you extracted to the SD card.
Step 4: Turn your car on, and insert the SD c
