Carrier 40QSM009DS Service Manual page 103

16.3.7 IPM malfunction or IGBT over-strong current protection diagnosis and solution (P0)
Error Code
Malfunction
conditions
Possible causes
Trouble shooting:
Check the wiring between main PCB
and compressor. Does an error
exist?
No
Check the IPM. Is it in working
order?
Yes
Check the outdoor fan and the
outdoor unit ventilation. Is it in
working order?
Yes
Check the compressor resistance
values. Are they within acceptable
parameters?
Yes
Replace the outdoor main PCB
P0
When the voltage signal the IPM sends to the compressor drive
chip is abnormal, the display LED shows "P0" and the AC turn
off.
Wiring mistake
●
IPM malfunction
●
Faulty outdoor fan assembly
●
Compressor malfunction
●
Faulty outdoor PCB
●
Yes
No
No
No
Ensure a proper connection or
replace the wires and connectors
Replace the IPM board or replace
the main PCB
Please refer to the solution to the
"fan speed is out of control"
malfunction
Replace the compressor
100