SiUS371901E
Troubleshooting by Error Code
Service Diagnosis
278
3.22 Thermistor Abnormality
Error Code
C4, C5, C9, CA
Applicable
Models
C4, C5
: All indoor units
C9
: except FXTQ-TA and CXTQ-TA models
CA
: FXMQ-PB models only
Method of Error
Detection
The error is detected by temperature detected by thermistor.
Error Decision
Conditions
The thermistor becomes disconnected or shorted while the unit is running.
Supposed
Causes
Defective thermistor
Defective indoor unit control PCB
Defective connector connection
Broken or disconnected wire
Troubleshooting
Notes:
∗
1. Error code and thermistor
∗
C9
for FXTQ-TA and CXTQ-TA models
Is the
thermistor normal?
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Remove the thermistor from the
indoor unit control PCB. Then,
insert the connector again.
Remove the thermistor from
the indoor unit control PCB,
and then make resistance
measurement of the thermistor
using a multimeter.
Normal?
Normal (The error is caused by
defective contact.)
YES
NO
Replace the indoor unit
control PCB (A1P).
YES
Replace the thermistor (
∗
1).
NO
CHECK 11
Error Code
Thermistor
Except
FXMQ-PB and
FXTQ-TA,
CXTQ-TA
FXMQ-PB
FXTQ-TA,
CXTQ-TA
C4
Indoor heat exchanger liquid pipe thermistor
R2T
R2T
R2T
C5
Indoor heat exchanger gas pipe thermistor
R3T
R3T
R3T
C9
Suction air thermistor
R1T
R1T
∗
2
CA
Discharge air thermistor
—
R4T
—
CHECK 11
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 ...