Daikin Emura 3 Series Service Manual page 37

3.5.33 U5-00 – Communication abnormality between indoor unit main PCB and remote controller
RXJ20~50A + FTXJ-A(W)(S)(B)
Split Emura 3 R32
ESIE22-04 – 2022.04
3 Perform a check of the main PCB. See Main PCB.
Possible cause: Faulty main PCB.
4 Perform a check of the outdoor unit fan motor. See Outdoor unit fan motor.
Possible cause: Faulty outdoor unit fan motor.
5 Perform a check of the indoor unit main PCB. See Indoor unit PCB.
Possible cause: Faulty indoor unit main PCB.
6 Perform a check of the indoor unit power PCB. See Indoor unit power PCB.
Possible cause: Faulty indoor unit power PCB.
Prerequisite: Stop the unit operation via the user interface.
Prerequisite: Turn OFF the respective circuit breaker.
7 Wait until the rectifier voltage is below 10 V DC.
DANGER: RISK OF ELECTROCUTION
Wait for at least 10 minutes after the circuit breaker has been turned OFF, to be sure
the rectifier voltage is below 10 V DC before proceeding.
8 Check that the thermal interface grease is applied properly on the (PCB or
refrigerant piping) contact surface of the heat sink. Adjust if needed.
Possible cause: Thermal interface grease NOT applied properly on the heat
sink.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
Trigger
Transmission abnormality
between indoor unit main
PCB and remote
controller.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Check for improper combination of the indoor unit and the remote controller.
See Business Portal for more information.
Possible cause: Improper combination of indoor unit and remote controller.
2 Perform a check of the remote controller. See documentation of the specific
remote controller for more information.
Possible cause: Faulty remote controller.
3 Perform a check of the indoor unit main PCB. See Indoor unit PCB.
Possible cause: Faulty indoor unit main PCB.
Effect
Unit will stop operating.
draft – 22/04/2022 08:50
3 | Troubleshooting
Reset
Auto reset.
Service manual
37