ACiQ PC02

What does ACiQ PC02 mean?

PC02 is a compressor top (or IPM) temperature protection fault. On models with an overload protector, it is flagged when the protector's sampling voltage is not 5V; the protection also trips when the IPM module temperature rises above a set value. It typically points to restricted airflow, an overload-protector issue, or a refrigerant-system problem driving temperatures too high.

Symptoms

• PC02 shown on the display
• Compressor stops on protection, especially under heavy load
• Hot outdoor or indoor airflow restriction
• Compressor top running above about 90°C before tripping

Common causes

• Obstructed indoor or outdoor airflow / dirty heat exchanger
• Faulty overload protector (OLP) or its wiring
• Abnormal refrigerant system condition
• Faulty IPM board or outdoor control PCB

Diagnostic steps

1. 01

   Clear airflow obstructions

   Check whether the air flow of the indoor and outdoor units is obstructed and clear the inlets, outlets, or heat exchanger.

2. 02

   Power cycle and wait

   Turn off the power and turn it on about 10 minutes later, then check if the compressor top is still above 90°C.

3. 03

   Check the overload protector

   Inspect the OLP connection and measure the resistance across its two ports; if it is not zero, replace the OLP.

4. 04

   Verify the refrigerant system

   Confirm the refrigerant system is normal and repair it if a problem is found.

5. 05

   Replace the control board

   If the above are good, replace the outdoor control PCB.

When to call a professional

PC02 can stem from refrigerant-system faults and requires measuring the overload protector and possibly replacing the IPM or control board around high-voltage, capacitor-charged electronics. Refrigerant verification needs EPA certification. If clearing airflow blockages does not resolve PC02, contact a licensed HVAC technician; OLP testing, refrigerant work, and board replacement must be done by a qualified professional.