Carrier 40MPHA Service Manual page 36

P4 (Inverter compressor drive error diagnosis and solution)
Description: If the temperature of IPM module is higher than limited value, the LED displays this failure code.
Recommended parts to prepare:
• Wiring mistake
• PM malfunction
• Outdoor fan assembly faulty
• Compressor malfunction
• Outdoor PCB faulty
Troubleshooting and Repair:
Check the wiring between the
PCB and compressor.
Is it improperly wired ?
Check the IPM.
Is it functioning
properly?
Check the outdoor fan and
the outdoor unit ventilation.
Is it functioning
properly?
Check the compressor
resistance values.
Are they within
acceptable parameters ?
Replace the outdoor PCB.
36
NO
YES
YES
YES
Specifications subject to change without notice.
Ensure proper connections or replace
YES
the wires and connectors.
Replace the IPM board or replace
NO
Please refer to "Fan Speed
NO
Malfunction" solution.
Replace the compressor.
NO
the outdoor PCB.
40MPHA-03SM