Whirlpool duet over fills, then F-20

I have replaced the water inlet valve and drain pump on my whirlpool duet after getting repeated F-20 codes. Fixed it at first. Now the washer over fills, then F-20. Drains fine when I push reset. If I leave it unplugged 30 minutes and restart all is well. Do you think I need a new control module? If so, which one? My model number is wfw8300sW02. Or should I replace a different part? BTW, thanks for the fast shipping on the parts so far.