U4-00 - Indoor/Outdoor Unit Communication Problem - Daikin Emura RXJ20A5V1B Service Manual

3.5.32 U4-00 – Indoor/outdoor unit communication problem
RXJ20~50A + FTXJ-A(W)(S)(B)
Split Emura 3 R32
ESIE22-04B – 2022.08
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 "4.2 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" [ 134].
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" [ 103].
Possible cause: Faulty indoor unit main PCB.
7 Perform a check of the indoor unit power PCB. See
4
PCB" [ 108].
Possible cause: Faulty indoor unit power 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" [ 180].
Possible cause:
▪ Faulty or disturbance of the power supply (power supply MUST be within
range of nominal operating voltage ±4%),
▪ Power drop,
▪ Short circuit.
"4.12 Main
Effect
Unit will stop operating.
3 Troubleshooting
|
4
62].
"4.13 Outdoor unit fan
4
PCB" [ 117].
"4.9 Indoor unit main
"4.10 Indoor unit power
Reset
Power reset via outdoor
unit.
"5.1 Electrical
Service manual
41