Running a Vehicle Health Report records the current version of your SYNC software. (Show me how to run a Vehicle Health Report.)
After running the report, you will receive an email notifying you that your Vehicle Health Report is ready.
Check your Owner Account. If there are no updates to download, your SYNC version is up to date.
Your dealer can also help you figure out your SYNC version. There may be a charge for this service, so check with your dealer first. (Help me locate a dealer.)