Pioneer YN020GMFI22M2D Service Manual page 69

8.4.2.11 P3 (Current overload protection) diagnosis and solution.
Error Code
Malfunction decision
conditions
Supposed causes
Trouble shooting:
P3
If the outdoor current exceeds the current limit value, the LED
will display the failure.
● Wiring mistake
● Over load protector faulty
● System block
● Outdoor PCB faulty