U4 Transmission Error Between Indoor Unit And Outdoor Unit - Daikin R71FUV1 Service Manual

Troubleshooting by Remote Controller
U4
3.93
Between Indoor Unit and
Outdoor Unit
Remote Controller Display
U4
Applicable Models
RZ(Y)
Method of Error Detection
Micro-computer checks if transmission between indoor
and outdoor units is normal.
Error Decision Conditions
When transmission is not carried out normally for a
certain amount of time
Supposed Causes
Wiring indoor-outdoor transmission wire is incorrect.
Defective indoor unit PCB
Defective outdoor unit PCB
External factor (Noise, etc.)
Power supply -open phase
Transmission Error
Si20-701_B
381