LG Multi V ARWM072CAS5 Service Manual page 128

Self-diagnosis function
Error No. Error Type
42*
Master 421
Sensor error of low
pressure
Slave1 422
Slave2 423
43*
Master 431
Sensor error of
Slave1 432 high pressure
Slave2 433
n Error diagnosis and countermeasure flow chart
Is sensor connected
to PCB correctly?
Yes
After replacement of
outdoor unit main PCB
is the system normal?
Yes
END
High pressure sensor
Pressure sensor connector
Error Point
Abnormal value of
sensor
(Open/Short)
Abnormal value of
sensor
(Open/Short)
No
Connect sensor to PCB correctly
No
Replace corresponding
pressure sensor
Low pressure sensor
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Main Reasons
1. Bad connection of low pressure sensor connector
2. Defect of low pressure sensor connector (Open/Short)
3. Defect of outdoor PCB
1. Bad connection of high pressure sensor connector
2. Defect of high pressure sensor connector (Open/Short)
3. Defect of outdoor PCB
High pressure sensor
Low pressure sensor
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