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

Troubleshooting
4.6 Signal Transmission Error (between Indoor Unit and
Outdoor Unit)
U4
Remote
Controller
Display
Method of The data received from the outdoor unit in indoor unit-outdoor unit signal transmission is
checked whether it is normal.
Malfunction
Detection
Malfunction The data sent from the outdoor unit cannot be received normally, or the content of the data is
abnormal.
Decision
Conditions
Supposed
Causes
Troubleshooting
Check No.10
Refer to P.127
87
Wiring error
Breaking of the connection wires between the indoor and outdoor units (wire No. 3)
Defective outdoor unit PCB
Defective indoor unit PCB
Disturbed power supply waveform
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
Check the indoor unit-outdoor unit
connection wires.
Is there any wiring error?
NO
Check the voltage of the
connection wires on the indoor
terminal board between No. 1
and No. 3, and between No. 2
and No. 3.
Properly insulated?
NO
Check the LED A on the outdoor
unit PCB.
Is LED A blinking?
YES
Check No.10
Check the power supply
waveform.
Is there any disturbance?
YES
YES
YES
∗ Before you check the LED A,
cancel the standby electricity
saving function by operating
fan operation with the remote
controller.
∗ Wait at least for 7 sec. after
turning on the power.
NO
NO
SiBE041101
Correct the indoor unit-outdoor
unit connection wires.
Replace the connection wires
between the indoor and
outdoor units.
Diagnose the outdoor unit
PCB.
Replace the indoor unit PCB.
Locate the cause of the
disturbance of the power
supply waveform, and correct
it.
Service Diagnosis
(R12160)