sounds like exactly the same problem i just had. The unit is stick on Program Forced Write.
Followed the steps exactly so why will it brick. My screen is currently still on and seems i need to pull my battery to switch it off. Only reason i updated was to get the appradio working, now this.....
Update
Upon returning to my car, the screen was off and the system seems to be fine now. Did give me a lil bit of a scare. Don't even care if the firmware update completed, just glad to have it back.