SiUS371901E
Troubleshooting by Error Code
Service Diagnosis
346
Troubleshooting
Do all
indoor unit
remote controllers in
the same refrigerant
system display
U4
?
Are the
indoor-outdoor and
outdoor-outdoor
transmission wirings
normal?
Fuse on
the outdoor unit main
PCB has blown
out.
Does the
seven-segment
display show (1) or (2)?
(
∗
1)
The
lamp does not turn
OFF for a period of 12
minutes or more.
Is
voltage
between L1 and N
terminals of the outdoor unit
main PCB within ±10% of
the voltage
range?
Does the
microcomputer
normal monitor indication
lamp (HAP) on the outdoor
unit main PCB
blink?
Has the
indoor or
outdoor unit main
PCB been replaced, or
has the indoor-outdoor or
outdoor-outdoor
transmission
wiring been
modified?
U4-01
∗
1. :OFF :ON :BLINK
SEG1 SEG2 SEG3
(1)
(2)
Correct the voltage.
Replace the fuse.
Press and hold the
RETURN
(BS3)
button on the outdoor
unit main PCB for a period of
5 seconds or more.
YES
NO
YES
YES
Replace the indoor unit
control PCB.
Press and hold the
RETURN
(BS3)
button on the master
outdoor unit main PCB for a
period of 5 seconds or more.
(The system will not operate
for a period of 12 minutes at
maximum.)
Modify the transmission
wirings.
YES
Refer to troubleshooting
U4-03
(Indoor unit system
transmission error)
NO
NO
NO
Replace the outdoor unit
main PCB.
NO
YES
NO
NO
NO
YES
NO
Reset the power supply once.
YES
Check for details of error in
monitor mode.
YES
YES
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Any open
phase in the
power supply wiring or
any wrong wiring of
the outdoor
unit?
NO
Correct the power supply
wiring.
YES
Check the power supply wiring.
A
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Summary of Contents for REYQ72-456XATJU
Page 415: ...SiUS371901E Wiring Diagrams Appendix 402 REYQ144 168XATJU 2D119206A ...
Page 416: ...Wiring Diagrams SiUS371901E 403 Appendix REYQ72 96 120XAYDU 2D119207B ...
Page 417: ...SiUS371901E Wiring Diagrams Appendix 404 REYQ144 168XAYDU 2D119208B ...
Page 418: ...Wiring Diagrams SiUS371901E 405 Appendix REYQ72 96 120 144 168XAYCU 2D119209A ...
Page 421: ...SiUS371901E Wiring Diagrams Appendix 408 FXZQ05 07 09 12 15 18TAVJU 3D110443A ...
Page 423: ...SiUS371901E Wiring Diagrams Appendix 410 FXEQ07 09 12 15 18 24PVJU 3D098557A ...
Page 426: ...Wiring Diagrams SiUS371901E 413 Appendix FXMQ07 09 12 15 18 24 30 36 48 54PBVJU 3D093209B ...
Page 428: ...Wiring Diagrams SiUS371901E 415 Appendix FXHQ12 24 36MVJU 3D048116C ...
Page 429: ...SiUS371901E Wiring Diagrams Appendix 416 FXAQ07 09 12 18 24PVJU C 3D075354D ...
Page 435: ...SiUS371901E Wiring Diagrams Appendix 422 VAM1200GVJU 3D073270D ...
Page 437: ...SiUS371901E Wiring Diagrams Appendix 424 1 4 2 Multi Branch Selector Unit BS4Q54TVJ 3D089123B ...
Page 438: ...Wiring Diagrams SiUS371901E 425 Appendix BS6 8Q54TVJ 2D089122B ...
Page 439: ...SiUS371901E Wiring Diagrams Appendix 426 BS10 12Q54TVJ 2D089121B ...
Page 440: ...Revision History Month Year Version Revised contents 04 2019 SiUS371901E First edition ...