Access our premium database of error codes, common faults, and professional repair solutions for Gree / Mace appliances.
Compressor loss step protection
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
Check compressor functionality and driver board.
Gree / Mace HC: Motor drive or inverter rotation anomaly in Air Conditioner / Heat Pump; drum/motor fails to spin at target RPM.
Defective 3-Phase Motor Windings / Tacho Generator / Carbon Brushes, open/short circuit in the wiring harness, or faulty connector on the drive motor, inverter & tachometer sensor.
Power Factor Correction error. Check inverter driver board.
Compressor demagnetization protection
Defective 3-Phase Motor Windings / Tacho Generator / Carbon Brushes, open/short circuit in the wiring harness, or faulty connector on the drive motor, inverter & tachometer sensor.
Check compressor internal condition or replace inverter board.
Outdoor DC fan motor malfunction
Defective 3-Phase Motor Windings / Tacho Generator / Carbon Brushes, open/short circuit in the wiring harness, or faulty connector on the drive motor, inverter & tachometer sensor.
Check outdoor fan motor and rotation.
Gree / Mace LC: Operational cycle fault detected during Air Conditioner / Heat Pump program execution.
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
Compressor failed to start. Check capacitors, wiring, and compressor windings.
Compressor loss of phase protection
Defective 3-Phase Motor Windings / Tacho Generator / Carbon Brushes, open/short circuit in the wiring harness, or faulty connector on the drive motor, inverter & tachometer sensor.
Check compressor phase connections and inverter output.
Compressor locked rotary protection
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
Compressor may be seized mechanically.
Over compressor phase current protection
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
Check compressor winding resistance and power supply.
Communication failure between main board and driver board
Defective PCB Power Supply Rails & DC Bus Filter Capacitors, open/short circuit in the wiring harness, or faulty connector on the electronic control board (pcb) & bus communications.
Check internal wiring between PCBs in outdoor unit.
IPM sensor circuit malfunction
Defective NTC Temperature Sensor Probe (Thermistor), open/short circuit in the wiring harness, or faulty connector on the ntc temperature sensor & thermistor.
1. Disconnect 230V mains power. 2. Unplug NTC thermistor harness connector. 3. Measure NTC resistance with multimeter across pins 1-2 (nominal: 4.8kΩ–12kΩ at 20°C–25°C; resistance should drop smoothly when probe tip is warmed). Replace sensor if open circuit (OL). 4. Reset: Power cycle reset: Disconnect appliance from 230V mains for 3 minutes. Press and hold Start/Power for 10 seconds while unplugged, then reconnect power.
IPM high temperature protection
Defective 3-Phase Motor Windings / Tacho Generator / Carbon Brushes, open/short circuit in the wiring harness, or faulty connector on the drive motor, inverter & tachometer sensor.
Check outdoor fan, heat sink, and ensure normal airflow around inverter board.
Current detect circuit malfunction or Current sensor malfunction
Defective PCB Power Supply Rails & DC Bus Filter Capacitors, open/short circuit in the wiring harness, or faulty connector on the electronic control board (pcb) & bus communications.
1. Disconnect 230V mains power for 3 minutes. 2. Inspect wire harness and edge connectors on control board for loose pins or oxidation. 3. Inspect mechanical linkages and sensors associated with subsystem. 4. Reset: Power cycle reset: Disconnect appliance from 230V mains for 3 minutes. Press and hold Start/Power for 10 seconds while unplugged, then reconnect power.
Over voltage protection for PN
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
Check incoming power supply voltage is not too high.
Low PN voltage protection
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
1. Disconnect 230V mains power for 3 minutes. 2. Inspect wire harness and edge connectors on control board for loose pins or oxidation. 3. Inspect mechanical linkages and sensors associated with subsystem. 4. Reset: Power cycle reset: Disconnect appliance from 230V mains for 3 minutes. Press and hold Start/Power for 10 seconds while unplugged, then reconnect power.
Capacitor charge malfunction
Defective 3-Phase Motor Windings / Tacho Generator / Carbon Brushes, open/short circuit in the wiring harness, or faulty connector on the drive motor, inverter & tachometer sensor.
Check inverter board capacitor and charging circuit.
Compressor phase current detection circuit malfunction
Defective PCB Power Supply Rails & DC Bus Filter Capacitors, open/short circuit in the wiring harness, or faulty connector on the electronic control board (pcb) & bus communications.
Check current detection circuitry on PCB.
Compressor protection against loss of phase
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
Check phase connections to the compressor.
PN voltage drop protection
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
Check power supply for severe voltage drops.
Compressor reverse protection
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
Check for correct phase sequence and wiring to the compressor.
AC current detect circuit malfunction
Defective PCB Power Supply Rails & DC Bus Filter Capacitors, open/short circuit in the wiring harness, or faulty connector on the electronic control board (pcb) & bus communications.
Inspect current detection circuit on the main board.
4-way valve reversal abnormal
Component fatigue, sensor feedback out of tolerance, wiring harness connector discontinuity, or electronic control board glitch.
Check reversing valve and coil for proper operation in heat cycle.
Disconnection of the exhaust temperature sensor
Defective NTC Temperature Sensor Probe (Thermistor), open/short circuit in the wiring harness, or faulty connector on the ntc temperature sensor & thermistor.
Reconnect or replace exhaust temperature sensor.
AC power zero voltage detect error
Defective PCB Power Supply Rails & DC Bus Filter Capacitors, open/short circuit in the wiring harness, or faulty connector on the electronic control board (pcb) & bus communications.
Check power supply voltage quality and main PCB zero-cross detection circuit.