Service Manual
Table Of Contents
- Cover
- Table of contents
- Part 1 List of Functions
- Part 2 Specifications
- Part 3 Printed Circuit Board Connector Wiring Diagram
- Part 4 Refrigerant Circuit
- Part 5 Functions and Control
- Part 6 Test Operation and Field Settings
- Part 7 Remote Controller
- Part 8 Troubleshooting
- 1. Troubleshooting with LED
- 2. Service Diagnosis
- 3. Error Codes and Description
- 4. Troubleshooting for CTXG, CTXS, FTXS, CDXS, FDXS, FVXS Series
- 5. Troubleshooting for FFQ Series
- 6. Troubleshooting for Branch Provider (BP) Unit
- 7. Troubleshooting for Outdoor Unit
- 8. Thermistor Resistance/Temperature Characteristics
- 9. Pressure Sensor
- 10. Method of Replacing Inverter’s Power Transistors Modules
- Part 9 Appendix
SiUS181631EA Troubleshooting for CTXG, CTXS, FTXS, CDXS, FDXS, FVXS Series
Troubleshooting 203
4.4 Thermistor or Related Abnormality
Error Code
C4, C9
Method of Error
Detection
The temperatures detected by the thermistors are used to determine thermistor errors.
Error Decision
Conditions
The voltage between both ends of the thermistor is either 4.96 V or more, or 0.04 V or less during
compressor operation.
Supposed
Causes
Disconnection of connector
Thermistor corresponding to the error code is defective.
Defective indoor unit PCB
Troubleshooting
Check No.01
Refer to P.205
C4 : Indoor heat exchanger thermistor
C9 : Room temperature thermistor
Note: When replacing the defective thermistor(s), replace the thermistors as ASSY.
YES
(R21870)
NO
Check No. 01
Check the thermistor resistance
value.
YES
NO
Caution
Correct the connection.
Replace the defective
thermistor.
Replace the indoor unit PCB
(control PCB).
Normal?
Normal?
Check the connection of
connectors.
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.