Daikin VRV RXYMQ-A Series Service Manual page 260

Troubleshooting by Error Code
254
U4-03
Indication
YES
after launch test
operation?
NO
Operate all indoor units.
NO
Do all units display U9?
YES
NO
Did 2 minutes or more
elapse after U9 is
displayed?
YES
SiME332106E
Check controller indoor units:
(1) Some error about
thermistor, or fan motor,
electronic expansion
valve, or defective PCB.
(2) Test operation was
interrupted by the MODE
(BS1) button.
Check all indoor error
indication.
Carry out the diagnosis again
after a lapse of 2 minutes or
more.
The PCBs of indoor units
displaying U9 are normal.
Check for indoor units of
other systems to troubleshoot
them according to relevant
error codes.
Part 6 Service Diagnosis