Troubleshooting Guide

Table Of Contents
7.12 P4/PC 04(Inverter compressor drive error diagnosis and solution)
Description: 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.
Recommended parts to prepare:
Connection wires
IPM module board
Outdoor fan assembly
Compressor
Outdoor PCB
Troubleshooting and repair:
Check the wiring between
PCB and compressor.
Does an error exist ?
Ensure proper connections or
replace the wires and connectors.
YES
NO
Are the IPM terminal
resistances uniform?
Replace the IPM board or
replace the outdoor PCB.
NO
Check the outdoor fan and the
outdoor unit ventilation.
YES
Is it in working order?
NO
Check the compressor
resistance values.
YES
Are they uniform?
Replace the compressor.
Replace the outdoor PCB.
YES
NO
Check if the IPM
installed correctly.
YES
NO
Correct the installation
, tighten the
screws and apply silicon grease
IPM continuity check
Troubleshooting 34
Note: For certain models, outdoor PCB cannot be removed separately. In this case, the outdoor electric
control box should be replaced as a whole.
Please refer to the solution of the
“Fan Speed is operating outside of
normal range” malfunction.