Daikin FTX09NMVJU, Service Manual

Page: 106 / 145

Troubleshooting SiUS091601E
95 Service Diagnosis
4.19 Thermistor or Related Abnormality (Outdoor Unit)
Error Code
H9
,
J3
,
J6
,
P4
Method of Error
Detection This fault is identified based on the thermistor input voltage to the microcomputer.
A thermistor fault is identified based on the temperature sensed by each thermistor.
Error Decision
Conditions
„
The voltage between the both ends of the thermistor is above 4.96 V or below 0.04 V with the
power on.
„ J3
error is judged if the discharge pipe temperature is lower than the heat exchanger
temperature.
Supposed
Causes
„
Disconnection of the connector for the thermistor
„
Thermistor corresponding to the error code is defective.
„
Defective heat exchanger thermistor in the case of
J3
error (outdoor heat exchanger thermistor
in cooling operation, or indoor heat exchanger thermistor in heating operation)
„
Defective outdoor unit PCB
Troubleshooting In case of
P4
Replace the outdoor unit PCB (main PCB).
P4
: Radiation fin thermistor
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.