Midea M4OC-36HRFN1-M - High Pressure Protection (P1) Diagnosis

9.4.2.9 P1(High pressure protection) error diagnosis and solution. (Only for M4OC-36HRFN1-M)
Error Code
P1
Malfunction decision
conditions
If the sampling voltage is not 5V, the LED will display the
failure.
Supposed causes
● Wiring mistake
● Over load protector faulty
● System block
● Outdoor PCB faulty
Trouble shooting:
High pressure protection
Judge 1: Whether the wiring
between the high pressure
switch and main control
board is connected well or
correctly
Method: Short connect the high
pressure protector socket,
check whether the system can
run normally or test the
resistance.
Yes
No
Connect it well
Replace outdoor main board
No
Replace high pressure protector
Yes
Judge 2: Whether
the high pressure
protector is broken
Check whether
the refrigerant
system is ok
Judge 3: Check whether the
outdoor ambient
temperature is higher than
43℃
No
Stop the unitYes
Judge 4: Check whether the
outdoor unit is bad
ventilation
No
Make the outdoor unit ventilate wellYes
Judge 5: Check whether the
heat exchanger is dirty
Clean the heat exchanger
Yes
Judge 6: Check whether the
refrigerant pipe is blocked
Let the refrigerant out, then use the
high pressure nitrogen or refrigerant to
blow pipe, vacuumize and charge the
refrigerant again
Yes