Troubleshooting
Si12-714
186
Service Diagnosis
5.7
Signal Transmission Error (between Indoor and Outdoor
Units)
Remote
Controller
Display
U4
Method of
Malfunction
Detection
The data received from the outdoor unit in indoor unit-outdoor unit signal transmission is
checked whether it is normal.
Malfunction
Decision
Conditions
When the data sent from the outdoor unit cannot be received normally, or when the content of
the data is abnormal.
Supposed
Causes
Faulty outdoor unit PCB.
Faulty indoor unit PCB.
Indoor unit-outdoor unit signal transmission error due to wiring error.
Indoor unit-outdoor unit signal transmission error due to disturbed power supply waveform.
Indoor unit-outdoor unit signal transmission error due to breaking of wire in the connection
wires between the indoor and outdoor units (wire No. 2).
Short circuit inside the fan motor winding.