U4-00 - Indoor/Outdoor Unit Communication Problem - Daikin FTXP20-71L Service Manual

2.5.29 U4-00 – Indoor/outdoor unit communication problem
ATXP20~35 + FTXP20~71 + ARXP20~35 + RXP20~71
Split Comfora R32
ESIE18-01E – 2023.01
Possible cause:
▪ Faulty or disturbance of the power supply (power supply MUST be within
range of nominal operating voltage ±4%),
▪ Power drop,
▪ Short circuit.
2 Perform a check of the compressor. See "3.2 Compressor" [
Possible cause: Faulty compressor or miswiring of the compressor power
supply cable.
3 Perform a check of the outdoor unit fan motor. See
4
motor" [ 100].
Possible cause: Faulty outdoor unit fan motor.
4 Perform a check of the main PCB. See
Possible cause: Faulty main PCB.
5 Wait until the compressor restarts.
Possible cause:
▪ Momentary drop of voltage,
▪ Momentary power failure.
6 Perform a check of the indoor unit main PCB. See
4
PCB" [ 78].
Possible cause: Faulty indoor unit main PCB.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
Trigger
Communication failure
between outdoor and
indoor unit.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Check if the power supply is compliant with the regulations. See
4
circuit" [ 142].
Possible cause:
▪ Faulty or disturbance of the power supply (power supply MUST be within
range of nominal operating voltage ±4%),
▪ Power drop,
▪ Short circuit.
2 Perform a check of the power supply, connections, wiring,... between the
outdoor unit and the indoor unit. See
Possible cause: Faulty wiring between the outdoor unit and the indoor unit.
3 Perform a check of the main PCB. See
"3.7 Main
Effect
Unit will stop operating.
"4.1 Electrical
"3.7 Main
2 Troubleshooting
|
4
52].
"3.8 Outdoor unit fan
4
PCB" [ 84].
"3.6 Indoor unit main
Reset
Power reset via outdoor
unit.
"4.1 Electrical
4
circuit" [ 142].
4
PCB" [ 84].
Service manual
35