Midea MEHS-09PSH1 Service Manual page 50

9.3.10 Inverter compressor drive error diagnosis and solution(P4)
Error Code
Malfunction decision
conditions
Supposed causes
Trouble shooting:
For 9K~18K:
P4
An abnormal inverter compressor drive is detected by a special
detection circuit, including communication signal detection,
voltage detection, compressor rotation speed signal detection
and so on.
Wiring mistake
●
IPM malfunction
●
Outdoor fan ass'y faulty
●
Compressor malfunction
●
Outdoor PCB faulty
●