Midea MSH-07CRN1, MSH-07HRN1, MSH-09CRN1, MSH-09HRN1, MSH-12CRN1, MSH-12HRN1 Manual page 304

11.1.10
Display
P3 Outdoor low temp. protection
This is optional, factory standard unit has not this function.
Unit stops when outdoor temp. is low than -15°C and lasting time more than 60 minutes, and unit runs
again when outdoor temp. more than -12°C.
Is the outdoor temp. low than -15°C?
No
Is the outdoor temp sensor right according to the table in clause 12
Yes
Replace the outdoor main board
11.1.11
Display
P4
Are the U,V,W connected to compressor and inverter module right?
Yes
Are the connectors CN6 and CN 11 right?
Yes
Is there +15 voltage between CN6
Yes
Replace outdoor main PCB
If the problem comes to again, check wingding resistance of inverter compressor, is it 0.64 ohm?
No
Replace inverter compressor
LED STATUS
LED STATUS
Inverter compressor error
No
Replace inverter module
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