Carrier 40MPHA Service Manual page 35

DIAGNOSIS AND SOLUTION (CONT)
P0 (IPM malfunction or IGBT over−strong current protection diagnosis and solution)
Description: When the voltage signal the IPM sends to the compressor drive chip is abnormal, the display LED displays "P0" and the air
conditioner turns off.
Recommended parts to prepare:
S
Wiring mistake
S
IPM malfunction
S
Faulty outdoor fan assembly
S
Compressor malfunction
S
Faulty outdoor PCB
Troubleshooting and Repair:
Check the wiring between
PCB and compressor
Does an error exist ?
Check the IPM
Is it in working order ?
Check the outdoor fan and the
outdoor unit ventilation
Is it in working order ?
Check the compressor
resistance values.
acceptable parameters ?
Replace the outdoor PCB
YES
NO
NO
YES
NO
YES
YES
Ensure proper connections or
replace the wires and connectors
Replace the IPM board or
replace the outdoor PCB
Refer to the solution
'Fan Speed is Out of Control" malfunction
NO Replace the compressor
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