Multi Plus ODU Main Board Troubleshooting

Fault Code	Fault Description	Possible Reason for Fault	Potential Fixes
1	Outdoor Ambient Temperature Sensor Fault	The outdoor ambient temperature sensor connection is loose The outdoor ambient temperature sensor has failed The sampling circuit has failed	Reconnect the outdoor ambient temperature sensor Replace the outdoor ambient temperature sensor Replace the outdoor board
2	Outdoor Coil Temperature Sensor Fault	The outdoor coil temperature sensor connection is loose The outdoor coil temperature sensor has failed The sampling circuit has failed	Reconnect the outdoor coil temperature sensor Replace the outdoor coil temperature sensor Replace the outdoor board
3	The Unit Over-Current Turn Off Fault	Control board current sampling circuit has failed The current is too high because the supply voltage is too low The compressor is blocked Overload in heating mode Overload in cooling mode	Replace the control board Replace the compressor
4	EEprom Data Error	EE components have failed EE components control circuit failed EE components have been inserted incorrectly	Replace the EE components Replace the outdoor control board Reassemble the EE components
5	Cooling Freezing Protection (the indoor coil temperature is too low) or Heating Overload (indoor coil temperature is too high)	The indoor unit isn't blowing air normally The room temperature is too low in cooling mode or the room temperature is too high in heating Air filter is dirty The duct resistance is too high to result in low air flow The setting fan speed is too low The indoor unit is not standard installed, air inlet is too near with air outlet