Before you begin applying any potential fixes, I strongly suggest you do the following:
- ensure you are using the latest iTunes version.
- ensure your iPhone has sufficient memory space to bring in a new update. One gigabyte or more is recommended.
- ensure your iPhone has enough battery power or sufficiently charged.
1st Workaround: Change the USB port/cable
As your first approach to fixing the error, try to change the USB port to which you connect the iPhone. Also try to change the cable you are using.
You can also try to use a different computer which has the latest iTunes version installed, if available. Doing so will help you further isolate the problem.
2nd Workaround: Backup Files and enter Recovery Mode
If this error still prompts even after changing the cables/port, while you're attempting to update the firmware without doing a clean restore, then you can immediately proceed with restoring your iPhone. But before you start, ensure you back up all your important files. You may refer to the following procedures, if you want.
1. Connect your iPhone to the computer.
2. Open iTunes.
3. Backup your iPhone.
4. After successfully backing up all your files, disconnect the iPhone and then exit iTunes.
5. Put your iPhone in recovery mode. You can do this by pressing and holding the power and home buttons on your phone until the screen goes blank.
6. Now go to your computer and open iTunes.
7. Connect your iPhone to the computer. iTunes will let you know if your phone is successfully connected and recognized in Recovery mode.
8. Whenever you're all set, go ahead and restore your phone as new. Doing so will erasing everything in it. No worry though because you have the backup to restore from.
Others who have encountered the same error code has fixed it by simply clearing out some apps and apps memory to free up some space on their device. So you might as well give it a try. There's nothing to lose if you do so, though.