Pioneer WYB-GMFI SERIES Service Manual page 51

9.2.5 IGBT over-strong current protection diagnosis and solution
Check whether the connections between
outdoor PCB and IPM are good?
Yes
Check whether the IPM is fixed to radiator
tightly
Replace the IPM
9.2.6 Over voltage or too low voltage protection diagnosis and solution
Is the power supply good?
Yes
Replace the outdoor e-box.
9.2.7 High temperature protection of compressor top diagnosis and solution
Does the compressor operate?
Yes
Is refrigerant circulation
volume normal?
No,
Charge refrigerant
Is the abnormality the same
after gas charging?
There is block (Such as capillary or
welded points of the pipes.)
No
The unit does not work normally
No
No
Is the connection good?
Is protector normal?
Replace the outdoor PCB.
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Fastening the IPM to the radiator
Replace the compressor
Make sure the power supply is normal.
No
Yes
No
Yes
Reconnect it
Replace it