Thermistor System Fault - Daikin E Series Service Manual

Troubleshooting

2.29 Thermistor System Fault

P4, J3, J6, H9
Remote
Controller Display
Outdoor Unit LED A5
Display
Method of This fault is identified based on the thermistor input voltage to the microcomputer.
A thermistor fault is identified based on the temperature detected by each thermistor.
Malfunction
Detection
Malfunction When power is supplied and the thermistor input is 4.98 V or more
or when the thermistor input is 0.02 V or less for 5 sec. continuously
Decision
Conditions
For J3,
"Discharge pipe thermistor < heat exchanger thermistor" is take into consideration to identify the
fault.
Supposed
Causes
180
5 -
Improper connection of connector
Defective thermistor
Defective indoor unit PCB
For J3, defective heat exchanger thermistor
(Cooling: outdoor heat exchanger thermistor, heating: indoor heat exchanger thermistor)
SiBE04-624
Service Diagnosis