Signal Transmission Error (Between Indoor Unit And Outdoor Unit) - Daikin CTXS07LVJU Service Manual

Troubleshooting for CTXS, FTXS, CDXS, FDXS, FVXS Series
5.5 Signal Transmission Error (Between Indoor Unit and
Outdoor Unit)
U4
Error Code
Method of Error The data received from the outdoor unit in signal transmission is checked whether it is normal.
Detection
Error Decision The data sent from the outdoor unit cannot be received normally, or the content of the data is
Conditions abnormal.
Supposed
Causes
122
Reduction of power supply voltage
Wiring error
Breaking of the connection wires between the indoor and outdoor units (wire No. 3)
Defective outdoor unit PCB
Short circuit inside the fan motor winding
Defective indoor unit PCB
Disturbed power supply waveform
SiUS121602E
Service Diagnosis