ACiQ PC00

What does ACiQ PC00 mean?

PC00 is an outdoor IPM (Intelligent Power Module) protection fault. The IPM drives the inverter compressor, and its protection trips when the module detects an abnormal condition. The diagnosis centers on the IPM board, the signal wiring between the IPM and main board, and the outdoor main control board.

Symptoms

• PC00 shown on the display
• Compressor will not run or stops shortly after starting
• Outdoor unit protection trips repeatedly
• No or weak heating and cooling output

Common causes

• Faulty IPM module board
• Loose or broken signal wire between the IPM board and main board
• Faulty outdoor main control board
• Fault in the electric control box

Diagnostic steps

1. 01

   Check the IPM board LED

   Verify at least one LED on the IPM board is lit, indicating the board is powered.

2. 02

   Inspect the signal wiring

   Check the signal wire between the IPM board and the main board and confirm it is connected properly; reconnect and retry.

3. 03

   Replace the IPM board

   If the fault persists with good wiring, replace the IPM board and check whether the system runs normally.

4. 04

   Replace the outdoor main board

   If the fault remains, replace the outdoor main board.

5. 05

   Replace the electric control box

   If the problem still is not resolved, replace the electric control box.

When to call a professional

PC00 involves the high-voltage inverter power module, where capacitors store dangerous charge even after the power is off and must be fully discharged before any work. Diagnosis requires antistatic precautions and board-level replacement. Always contact a licensed HVAC technician for PC00; the IPM, main board, and control-box work on these inverter condensers is hazardous and must be done by a qualified professional.