Daikin Super Multi Plus E-Series - Transmission Error between Indoor Unit and BP Unit

SiEN18-622 Troubleshooting for BP Unit
Troubleshooting 355
6.4 Transmission Error between Indoor Unit and BP Unit
Outdoor Unit
Indication
U4
Method of
Malfunction
Detection
The data received from the BP unit in indoor unit-BP unit signal transmission is checked
whether it is normal.
Malfunction
Decision
Conditions
When the data sent from the BP unit cannot be received normally, or when the content of the
data is abnormal.
Supposed
Causes
 Faulty BP unit PCB.
 Faulty indoor unit PCB.
 Indoor unit-BP unit signal transmission error due to wiring error.
 Indoor unit-BP unit signal transmission error due to disturbed power supply waveform.
 Indoor unit-BP unit signal transmission error due to breaking of wire in the connection wires
between the indoor and BP units (wire No. 2).