Troubleshooting
SiMT041311E
139
Service Diagnosis
2.12 Thermistor or Related Abnormality (Indoor Unit)
Error Code
C4
,
C9
Method of Error
Detection
The temperatures detected by the thermistors determine thermistor errors.
Error Decision
Conditions
The thermistor input is 4.96 V and more or 0.04 V and less during compressor operation.
Supposed
Causes
Disconnection of connector
Thermistor corresponding to the error code is defective.
Defective indoor unit PCB (A1P, A4P)
Troubleshooting
Check No.01
Refer to P.181
C4
: Indoor heat exchanger thermistor
C9
: Room temperature thermistor
YES
(R19725)
NO
Check No. 01
Check the thermistor resistance
value.
YES
NO
Caution
Correct the connection.
C4: Replace the indoor heat
exchanger thermistor.
C9: Replace the humidity
sensor PCB (A4P).
Replace the control PCB
(A1P).
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.
∗
To secure the connection,
once disconnect the connector
and then reconnect it.