York YHKE09XEEAMH-RX Service Manual page 48

9.2.10 Inverter compressor drive error diagnosis and solution(P4)
Error Code
Malfunction decision
conditions
Supposed causes
Trouble shooting:
Check if the wiring between main
PCB and compressor connected
well?
Yes
Check if the IPM installed correctly.
Yes
IPM continuity check. Check if the
IPM terminal resistance values are
uniform.
Yes
Check if the outdoor fan runs
properly or the outdoor unit
ventilation is good.
Yes
Check if the compressor resistance
values are uniform .
Yes
Replace the outdoor main PCB if the
main PCB and IPM are separate.
P4
An abnormal inverter compressor drive is detected by a special
detection circuit, including communication signal detection,
voltage detection, compressor rotation speed signal detection
and so on.
Wiring mistake
●
IPM malfunction
●
Outdoor fan ass'y faulty
●
Compressor malfunction
●
Outdoor PCB faulty
●
No
No
No
Correct the connection or
No replace the wires and
Correct the installation,
No tighten the screws and
apply silicon grease.
Replace the IPM board or replace
the main PCB if the IPM board and
main PCB are integrated together.
Please refer to the solution of 【Fan
Speed Has Been Out Of Control】
malfunction
Replace the compressor.
46
connectors.