Signal Transmission Error (Between Indoor Unit And Outdoor Unit) - Daikin FTXM-V Series Service Manual

SiUS042113E
4.9 Signal Transmission Error (Between Indoor Unit and
Outdoor Unit)
U4
Error Code
Method of Error
The signal transmission data received 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
 Power supply voltage out of specification
 Reduction of power supply voltage
Causes
 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
Part 6 Service Diagnosis
Troubleshooting
101