Error Code: PC 04 – Inverter Compressor Drive Error

Error Code: PC 04 – Inverter Compressor Drive Error

What this means:
This error indicates that the system has detected an abnormality in the inverter compressor drive circuit. It could be related to communication signal loss, abnormal voltage readings, or incorrect compressor rotation feedback.

Try this first (quick reset):

1. Turn off the power to the entire system.

2. Wait 2 minutes.

3. Turn the power back on and check the display.

• If the error clears — the issue may have been a temporary fault.

• If it returns — begin the full diagnosis below.

Next steps (for technicians):

1. Inspect wiring between compressor and PCB:

   • If connections are loose or miswired → correct or replace the wires and connectors.

2. Check the IPM module:

   • If the IPM board is faulty → replace the IPM board or the outdoor PCB.

3. Check outdoor fan and ventilation system:

   • If the outdoor fan is not working → refer to “Fan Speed Malfunction” (e.g., EC 07).

   • Ensure the heat exchanger is clean and the fan spins freely.

4. Check compressor resistance:

   • If resistance readings are outside the acceptable range → replace the compressor.

   • If resistance is normal → replace the outdoor PCB.

What you might need:

• Connection wires

• IPM module board

• Outdoor fan assembly

• Compressor

• Outdoor PCB

Helpful tip:
PC 04 often shares root causes with EC 07 (fan speed) and PC 00 (IPM protection). Always verify wiring and fan operation before replacing major components.

Click here to view the detailed guide.TS28