Thermistor Or Related Abnormality (Indoor Unit) - Daikin FTX-N Series Service Manual

Troubleshooting
4.5

Thermistor or Related Abnormality (Indoor Unit)

C4, C9
Error Code
Method of Error
The temperatures detected by the thermistors determine thermistor errors.
Detection
Error Decision
The voltage between the both ends of the thermistor is either 4.96 V or more, or 0.04 V or less
Conditions
during compressor operation.
Supposed
 Disconnection of connector
Causes  Defective thermistor(s)
 Defective indoor unit PCB
Troubleshooting
Check No.01
Refer to P.94
C4 : Indoor heat exchanger thermistor
C9 : Room temperature thermistor
Note: When replacing the defective thermistor(s), replace the thermistors as ASSY.
65
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
Check the connection of
connectors.
Normal?
YES
Check No. 01
Check the thermistor resistance
value.
Normal?
YES
NO
NO
SiUS041638EA
Correct the connection.
Replace the defective
thermistor.
Replace the indoor unit PCB
(control PCB).
(R21870)
Service Diagnosis