There are four possible causes for F-01 that I know of:
CCU should make 2 clicks within 0.2 seconds when machine is plugged in. If hear none or only 1 click, replace CCU or replace relays K1 and K2 on CCU board (buy at Mouser or Digikey).
CCU does 2 clicks, but drum never rotates: replace MCU or re-solder GR1 bridge rectifier (4 pin device screwed to heat sink) on MCU board if no diodes or tracings look burnt.
CCU does 2 clicks, and drum rotates, and door locks, then later gets F-01: remove debris if drain pump is jammed or replace drain pump if it has a bad bearing or bad coil (should be ~12 ohms) AND / OR replace CCU or re-solder drain pump triac TR4 (loose pins) on CCU board.