Error Codes and Description SiUS091601EA123 Part 6 Service Diagnosis4. Error Codes and Description: Displayed only when system down occurs.ErrorCodes Description Reference PageFTX FVXS FDMQSystem 00 Normal — — —U0 Refrigerant shortage — — —U2 Low-voltage detection or over-voltage detection 133 133 146U4 Signal transmission error (between indoor unitand outdoor unit) 135 135 148U5 Signal transmission error (between indoor unitand remote controller) — — 150U8 Signal transmission error (between MAIN/SUBremote controller) — — 151UA Unspecified voltage (between indoor unit andoutdoor unit) 137 137 152IndoorUnitA1 Indoor unit PCB abnormality 124 124 138A3 Drain level control system abnormality — — 139A5 Freeze-up protection control/heating peak-cutcontrol 126 126 —A6 Indoor fan motor (DC motor) or relatedabnormality 128 128 140A8 Indoor fan PCB abnormality — — 142AF Humidifier or related abnormality — — 143C4 Indoor heat exchanger thermistor or relatedabnormality 132 132 144C5 — — 144C9 Room temperature thermistor or relatedabnormality 132 132 144CJ Remote controller thermistor abnormality — — 145OutdoorUnitE1 Outdoor unit PCB abnormality 153E5 OL activation (compressor overload) 154E6 Compressor lock 157E7 DC fan lock 158E8 Input overcurrent detection 159EA Four way valve abnormality 161F3 Discharge pipe temperature control 163F6 High pressure control in cooling 165F8 System shutdown due to temperature abnormalityin the compressor 167H0 Compressor system sensor abnormality 168H6 Position sensor abnormality 169H9 Outdoor temperature thermistor or relatedabnormality 172J3 Discharge pipe thermistor or related abnormality 172J6 Outdoor heat exchanger thermistor or relatedabnormality 172L3 Electrical box temperature rise 174L4 Radiation fin temperature rise 176L5 Output overcurrent detection 178P4 Radiation fin thermistor or related abnormality 172U7 Signal transmission error on outdoor unit PCB 180
