GREE         U-Match 5 SERIES UNIT SERVICE MANUAL 
61 
3.4.5 “E6” Communication Error 
Error display: ODU mainboard, IDU wired controller and IDU receiver light board will display E6 
Error judgment condition and method: 
If no communication between ODU and IDU or between IDU and wired controller in continuously 120s, this 
error will be reported. 
Possible reason:   
■Communication wire is connected improperly or loose. 
■Communication wire is cut off 
■Communication wire is in poor connection 
■Connected wired controller quantity or address setting is improper 
■Controller is abnormal 
Troubleshooting: