Signal Transmission Error (Between Indoor Unit And Outdoor Unit) - Daikin 4MXS-R Series Service Manual

SiUS121736EA
6.9 Signal Transmission Error (Between Indoor Unit and
Outdoor Unit)
U4
Error Code
Method of Error The signal transmission data from the outdoor unit 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
Service Diagnosis
Power supply voltage out of specification
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
Troubleshooting for SA Indoor Unit
174