I have a whirlpool duet dryer model # WGD 9 400SWD with a F01 error code. Unplugging and restarting after turning off power and back on. Still has F01 error code.

The F01 error is a failure code of the main control board. You will need to replace the control board. The control board you need for your model can be ordered from the link below: https://prismparts.com/products/whirlpool-dryer-main-electronic-control-board-pp2605106?_pos=1&_sid=3dfa26328&_ss=r.