Troubleshooting SiUS091601E69 Service Diagnosis4. Troubleshooting4.1 Error Codes and Description+: Displayed only when system-down occurs.Error Codes Description ReferencePageSystem 00 Normal —U2 Low-voltage detection or over-voltage detection 76U4 Signal transmission error (between indoor unit and outdoor unit) 78UA Unspecified voltage (between indoor unit and outdoor unit) 80IndoorUnit A1 Indoor unit PCB abnormality 70A5 Freeze-up protection control / heating peak-cut control 71A6 Fan motor (DC motor) or related abnormality 72C4 Indoor heat exchanger thermistor or related abnormality 75C9 Room temperature thermistor or related abnormality 75OutdoorUnit E1 Outdoor unit PCB abnormality 81E5+ OL activation (compressor overload) 82E6+ Compressor lock 84E7+ DC fan lock 85E8 Input overcurrent detection 86EA Four way valve abnormality 87F3 Discharge pipe temperature control 89F6 High pressure control in cooling 90H0 Compressor system sensor abnormality 92H6 Position sensor abnormality 93H9 Outdoor temperature thermistor or related abnormality 95J3+ Discharge pipe thermistor or related abnormality 95J6 Outdoor heat exchanger thermistor or related abnormality 95L3 Electrical box temperature rise 97L4 Radiation fin temperature rise 98L5+ Output overcurrent detection 99P4 Radiation fin thermistor or related abnormality 95
