I am getting an F01 error on my Whirlpool Duet dryer model #WED9400SW2. Any ideas what that means?

Bad control board. Might reset if you unplug it for 30 seconds.

You need to fix the main control board, more than likely. Look here: https://www.youtube.com/watch?v=xq-RNvQZvSg and https://www.youtube.com/watch?v=eWqrn5klxm0; and if the dryer is over two years old you need to totally tear it down and clean it, including putting white lithium grease on all bearings. Make sure to clean the blower and all air ducts with soap and water. You need to take it outside to do this, of course, but it's the only way to get it clean. Make sure you do not miss anything when you clean it or it will fail again. Here are some manuals: https://dl.dropboxusercontent.com/u/8010163/Whirlpool%20Dryers.zip
https://dl.dropboxusercontent.com/u/8010163/Electrical%20Theory%20and%20Diagnosis%20of%20Major %20Appliances%20Service%20Manual.pdf
https://dl.dropboxusercontent.com/u/8010163/How%20to%20use%20Test%20Equipment%20Service%20Manu al.pdf
Service Manual: https://dl.dropboxusercontent.com/u/8010163/Whirlpool%20L-79%20Duet%20Sport%20Dryer%20Service%20Manual.pdf
You should be able to fix it now. Get a good meter and a good soldering iron if you have to work on the board.