Pioneer YN020GMFI22M2D Service Manual page 38

8.4.1.4 Indoor fan speed has been out of control diagnosis and solution.
Malfunction decision
conditions
Supposed causes
Trouble shooting:
When indoor fan speed keeps too low (300RPM) for certain time, the
unit will stop and the LED will display the failure.
● Wiring mistake
● Fan ass'y faulty
● Fan motor faulty
● PCB faulty