SiUS091601EA Troubleshooting for Outdoor Unit
Part 6 Service Diagnosis 172
7.12 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 either 4.96 V or more, or 0.04 V or less
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
Defective thermistor(s)
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.