Thermistor Or Related Abnormality (Outdoor Unit) - Daikin FTXM-K Series Service Manual

Troubleshooting

4.21 Thermistor or Related Abnormality (Outdoor Unit)

H9, J3, J6, P4
Error Code
Method of Error 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.
Detection
Error Decision
Conditions
Supposed
Causes
Troubleshooting In case of
Replace the outdoor unit PCB (main PCB).
P4
91
The voltage between the both ends of the thermistor is 4.96 V and more or 0.04 V and less
during compressor operation.
J3
error is judged if the discharge pipe temperature is lower than the heat exchanger
temperature.
Disconnection of the connector for the thermistor
Thermistor corresponding to the error code is defective.
Defective heat exchanger thermistor in the case of
thermistor in cooling operation, or indoor heat exchanger thermistor in heating operation)
Defective outdoor unit PCB
P4
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
: Radiation fin thermistor
J3
error (outdoor heat exchanger
Service Diagnosis
SiBE041434E