SiUS042113E
Troubleshooting
Part 6 Service Diagnosis
101
4.9 Signal Transmission Error (Between Indoor Unit and
Outdoor Unit)
Error Code
U4
Method of Error
Detection
The signal transmission data received from the outdoor unit is checked whether it is normal.
Error Decision
Conditions
The data sent from the outdoor unit cannot be received normally, or the content of the data is
abnormal.
Supposed
Causes
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
Summary of Contents for FTXM-V Series
Page 16: ...SiUS042113E 12 Part 2 Specifications 1 Specifications 13 Part 2 Specifications...
Page 96: ...Troubleshooting SiUS042113E 92 Part 6 Service Diagnosis Reference Check No 01 Refer to P 134...
Page 150: ...Check SiUS042113E 146 Part 6 Service Diagnosis 18 24 class R24539 DC DC W V U...
Page 166: ...Piping Diagrams SiUS042113E 162 Part 8 Appendix RXM24VVJU 3D132217...
Page 171: ...SiUS042113E Operation Limit Part 8 Appendix 167 3 Operation Limit RXM09 12 18 24VVJU 3D133582A...