The only way to know if it is the Sync unit - is to remove it.
Locate Passenger side Glove Box, look under it you'll see something like this...
To gain access - you just need to untuck the FELT kick panel - it's got tabs that go into slots towards the front firewall.
Just "pucker pop" the FELT to pull the tabs away from their slots and then you can swing it down and away, then up towards the glovebox door.
It is under the glovebox and the "splash cover" FELT cover kick panel - tucked in underneath it - to reveal this...
You'll see Recessed Hex Head screws - 4 of them - in black - two on each side of this rectangle box.
If the unit was ever hit, struck or kicked from the passenger - this "box" can get damaged - there is a lot of SMD (Surface Mount Devices) on a board that houses this as a Logic unit that controls nearly everything on the car or at least has it's fingers in it.
Disconnect Battery Ground wait one minute...then proceed...
You can also see round head Hex SOCKET head - it has 4 of them - you can remove the box, by removing the 4 black recessed screws - the USB Port connector is a "pinch" type so you'll need to locate it's tab and press pinch it to pull it out to remove. The other MAIN HARNESS Connector is a grey "flip to the side" tab release to loosen the harness - the box screws can be removed to help you obtain a better grip and it's easier to get the connectors undone - install is the reverse.
IF you are having problems with the SYNC II unit - or the Radio seems to want to "hang up" and not power up - there may be a condition that itself needs to be cleared before you can even power the radio to even work.
Each vehicle's "SYNC" unit has a unique Serial ID that ID's itself to the vehicles VIN and all the modules it connects to thru the USB and SERIAL IO on the Main wiring harness - it communicates this to the vehicle and can even receive "signal" from the radio antenna and execute a reflector "ID" Ping from itself Its' part of the Passive an Anti-Theft system in these things.
IF it sees something wrong - or itself needs to "refresh" the ID to the system - it can take several minutes for the condition to complete and clear so you can operate the radio. The Radio itself needs SYNC to operate it's controls - so if it's hung up on something, SYNC can't "see" the other pieces of hardware demanding attention.
So if you're having issues with the Radio - it may not be the radio - or if it is, it's not connecting to SYNC - so both the SYNC and the Radio connectors needs to be popped off - then put back on - reseated to hopefully clear the condition.
IT is not out of the question that if some damage has happened to the SYNC unit - the unit itself will have to be replaced and the DEALER it have to "re-train" the new SYNC and it's ID to the other Modules.