Error Code: PC 04 – Inverter Compressor Drive Error

Error Code: PC 04 – Inverter Compressor Drive Error
Applies to LETO and AURA Series

What this means:
The system has detected an abnormal signal in the inverter compressor drive. This could involve issues with voltage, communication signals, or compressor rotation speed — all critical for efficient operation.

Try this first (quick check):

1. Turn off power to the system completely.

2. Wait 2 full minutes.

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

• If the error clears — it may have been a temporary inverter signal fault.

• If the error remains — follow the steps below.

Next steps (for technicians):

1. Check the wiring between the outdoor PCB and compressor.

   • Replace or re-secure if connections are damaged or loose.

2. Test the IPM terminal resistance:

   • If uneven → replace the IPM board or outdoor PCB.

3. Inspect the outdoor fan and unit ventilation:

   • If the fan isn’t operating properly, refer to the “fan speed out of range” guide.

4. Check the compressor resistance:

   • If resistance is abnormal → replace the compressor.

   • If resistance is fine, replace the outdoor PCB.

5. Verify IPM installation:

   • Tighten screws, confirm thermal contact, and apply silicon grease if needed.

What you might need:

• IPM module board

• Outdoor PCB

• Compressor

• Outdoor fan assembly

• Connection wires

Helpful tip:
This error often involves multiple components. Before replacing the compressor, always check fan function, wiring integrity, and IPM installation quality.

Click here to view the detailed guide.TS12-S