Mitsubishi Electric

Indoor temperature sensor malfunction. Check sensor connections and replace if necessary.

Evaporator temperature sensor fault. Professional sensor replacement required.

Outdoor coil temperature sensor malfunction. Check outdoor unit sensor connections.

Outdoor ambient temperature sensor fault. Professional sensor replacement needed.

Communication failure between indoor and outdoor units. Check control wiring.

Indoor unit communication fault. Inspect indoor control board and connections.

External control signal error. Check external control connections and settings.

Compressor discharge temperature sensor fault. Professional replacement required.

Compressor suction temperature sensor malfunction. Check sensor and connections.

Condensate drain pan sensor fault. Check sensor and drainage system.

Inverter control circuit malfunction. Professional diagnosis and repair required.

Power module malfunction. Professional power module replacement needed.

Compressor discharge pressure too high. Check refrigerant charge and condenser.

Inverter heat sink overheating. Check outdoor unit ventilation and clean coils.

Current sensor fault in inverter circuit. Professional inverter repair needed.

Compressor motor malfunction. Professional compressor diagnosis required.

Indoor or outdoor fan motor fault. Check motor operation and connections.

Compressor discharge pressure too low. Check for refrigerant leaks.

Outdoor ambient temperature sensor fault. Replace outdoor temperature sensor.

Motor position detection fault. Professional motor diagnosis required.

Supply voltage too low. Check electrical connections and utility supply.

Refrigerant leak detected. Professional leak repair and recharge required.

Compressor oil level low. Professional oil level check and refill needed.

Suction pressure too low. Check for refrigerant shortage or restrictions.

Superheat too low. Check expansion valve and refrigerant flow.

Subcooling too low. Check refrigerant charge and condenser performance.

Ambient temperature too low for operation. Check operating conditions.

Indoor temperature below operating range. Check system settings.

Air filter severely clogged. Clean or replace air filters immediately.

Indoor coil freeze protection activated. Check airflow and refrigerant levels.

Condensate overflow protection activated. Check drain system.

Reversing valve malfunction. Professional valve inspection and replacement needed.

Fan speed control fault. Check fan motor and control electronics.

Refrigerant flow control malfunction. Check expansion valve operation.

Defrost cycle malfunction. Check defrost sensors and control.

Fresh air damper control fault. Check damper motor and position.

High pressure switch activated. Check condenser coil and refrigerant charge.

Compressor overheating protection. Check refrigerant levels and electrical supply.

Compressor discharge temperature too high. Professional diagnosis required.

Superheat too high. Check expansion valve and refrigerant charge.

Subcooling too high. Check refrigerant overcharge and condenser operation.

Supply voltage too high. Check electrical supply and voltage regulation.

Ambient temperature exceeds operating range. Improve ventilation.

Indoor temperature above operating range. Check system capacity.

Main control board fault. Professional board replacement required.

Indoor and outdoor unit mismatch. Verify system compatibility.

System configuration error. Check system settings and parameters.

Control sequence malfunction. Professional diagnosis required.

Conflicting user settings detected. Review and correct settings.