Hi,
I found this information at esportsheadlines.com, there’s an extensive list of error codes listed.
Error Code 16 Explained: This error occurs when you run into a generic error while trying to set your internal clock.
How to solve Error Code 16: To fix this, start the Xbox with the Eject button if your console supports dual-boot. In case it doesn’t, but your system is modded, you can also try booting into AID or Slayers from your PC and then trying to install the stock dashboard on the console’s C: drive. If that doesn’t help, find someone who has a working Xbox, and plug in your HDD to the working system to reinstall Microsoft stock dashboard. Once your console is back working again, make sure to softmod your console to the latest version to avoid something like this happening again.
Hope this helps