Daikin FTKE25BVM, Service Manual

Page: 205 / 298

Troubleshooting Si12-411A
194 Service Diagnosis
5.19 Thermistor or Related Abnormality (Outdoor Unit)
Remote
Controller
Display
P4, J3, J6, J8, J9, H9
Outdoor Unit LED
Display A
5
1
4
2
4
3
1
4
1
Method of
Malfunction
Detection This type of error is detected by checking the thermistor input voltage to the microcomputer.
[A thermistor error is detected by checking the temperature being detected by each thermistor.]
Malfunction
Decision
Conditions When the thermistor input is above 4.96 V or below 0.04 V with the power on, the J3 error is
judged if the discharge pipe thermistor temperature is smaller than the condenser thermistor
temperature, or the system will be shut down if all the units are judged with the
J8
error.
Supposed
Causes
„
Connector in poor contact
„
Thermistor defective
„
Outdoor unit PCB defective
„
Indoor unit PCB defective
„
Condenser thermistor defective in the case of
J3
error (outdoor unit heat exchanger
thermistor in the cooling mode, or indoor unit heat exchanger thermistor in the heating
mode)