Thermistor Or Related Abnormality (Outdoor Unit) - Daikin 4MXL-T Series Service Manual

Troubleshooting for Outdoor Unit

7.16 Thermistor or Related Abnormality (Outdoor Unit)

H9, J3, J6, J8, J9, P4
Error Code
Outdoor Unit LED A j 1 i 2 i 3 h 4 h 5 h
Display
Method of Error This fault is identified based on the thermistor input voltage to the microcomputer.
Detection A thermistor fault is identified based on the temperature sensed by each thermistor.
Error Decision
 The voltage between the both ends of the thermistor is above 4.96 V or below 0.04 V with the
Conditions
 J3 error is judged if the discharge pipe temperature is lower than the heat exchanger
 The system is shut down if all the units are judged as the J8 error.
Supposed
 Disconnection of the connector for the thermistor
Causes  Defective thermistor(s)
 Defective heat exchanger thermistor in the case of J3 error (outdoor heat exchanger thermistor
 Defective outdoor unit PCB
Troubleshooting
In case of P4
Replace the outdoor unit PCB (main PCB).
P4 : Radiation fin thermistor
224
power on.
temperature.
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.
SiUS121827E
Part 6 Service Diagnosis