Ran the update Sync Gen2 v3.6.2 and no data was lost other then resetting the clock and pairing the phone. Problem was when I ran a VHR, two systems were unavailable (Restraints & Driver Assistance as well as check Fluid & Filters. Customer service (1-800 392-3673 option 1 and then option 3) 1st time suggested a master reset and if that didn't work open door and close door and wait 30 seconds then and and do a master reset.
Followed both suggestions but did not work. I asked if I would lose any data and they indicated no. You lose your radio stations and your favorites on the navigation system, they need some retraining.
2nd time I called customer service I was informed the dealer has a way of doing a hard reset. Have another apt with dealer and don't know if this will work