Thermistor Or Related Abnormality (Outdoor Unit) - Daikin FTX20K(2)V1B Service Manual

Troubleshooting

4.19 Thermistor or Related Abnormality (Outdoor Unit)

H9, J3, J6, P4
Error Code
This fault is identified based on the thermistor input voltage to the microcomputer.
Method of Error
A thermistor fault is identified based on the temperature sensed by each thermistor.
Detection
 The voltage between the both ends of the thermistor is above 4.96 V or below 0.04 V with
Error Decision
Conditions
 J3 error is judged if the discharge pipe temperature is lower than the heat exchanger
 Disconnection of the connector for the thermistor
Supposed
 Thermistor corresponding to the error code is defective.
Causes
 Defective heat exchanger thermistor in the case of J3 error (outdoor heat exchanger
 Defective outdoor unit PCB
In case of P4
Troubleshooting
Replace the outdoor unit PCB (main PCB).
P4 : Radiation fin thermistor
73
the power on.
temperature.
thermistor in cooling operation, or indoor heat exchanger thermistor in heating operation)
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
SiBE041525F
Service Diagnosis