Daikin FTXS30HVJU - Signal Transmission Error (between Indoor and Outdoor Unit)

SiUS04-924 Troubleshooting
Service Diagnosis 79
4.6 Signal Transmission Error (between Indoor and Outdoor
Unit)
Remote
Controller
Display
U4
Method of
Malfunction
Detection
The data received from the outdoor unit in indoor unit-outdoor unit signal transmission is checked
whether it is normal.
Malfunction
Decision
Conditions
When the data sent from the outdoor unit cannot be received normally, or when the content of the
data is abnormal.
Supposed
Causes
 Faulty outdoor unit PCB / Faulty indoor unit PCB
 Indoor unit-outdoor unit signal transmission error due to wiring error / due to disturbed power
supply waveform / due to breaking of wire in the connection wires between the indoor and
outdoor units (wire No. 3)
 Short circuit inside the fan motor winding
Troubleshooting
Check No.10
Refer to P.110
Check the voltage of the indoor
unit-outdoor unit connection wires
between No. 1 and No. 3, and
Check No.10
Check power supply waveform.
YES
YES
Replace indoor unit control
PCB .
Locate the cause of the
disturbance of the power supply
waveform, and correct it.
NO
(R8300)
NO
YES
YES
NO
NO
Caution
Be sure to turn off the power switch before connecting or disconnecting
the connector, or parts damage may occur.
YES
NO
Correct the indoor unit-outdoor
unit connection wires.
Diagnose the outdoor unit.
Replace the connection wires
between the indoor and
outdoor units.
Replace fan motor and outdoor
unit PCB .
Does fan rotate
smoothly?
Is LED A flashing?
Is the voltage 0 V?
Is there any
disturbance?
Is there any wiring error?
Check the indoor unit-outdoor unit