Carrier 38QUA009DS, Service Manual, Page: 103 / 116

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