Fujitsu AU*24LUAR Service Instruction page 66

Trouble shooting 7
OUTDOOR UNIT Error Method:
INDOOR UNIT
Outdoor Temperature Sensor Error
Detective Actuators:
Outdoor Unit Main PCB Circuit
Outdoor Temperature Thermistor
Forecast of Cause :
1. Connector connection failure 2.Thermistor failure 3. Main PCB failure
Check Point 1 : Check connection of Connector
Check if connector is removed.
Check erroneous connection.
Check if thermistor cable is open.
>>Upon correcting the removed connector or mis-wiring, reset the power.
OK OK
Check Point 2 : Remove connector and check Thermistor resistance value Check Point 2 :
Thermistor Characteristics (Approx. value)
Temperature
Resistance Value (k )
Temperature
Resistance Value (k )
If Thermistor is either open or shorted, replace it and reset the power.
OK OK
Check Point 3 :
Check Point 3 : Check voltage of Main PCB (DC5.0V)
Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)
1 2
CN21 CN22
If the voltage does not appear, replace Main PCB.
Indicate or Display:
Indoor Unit
Outdoor Unit : LED 4 times blink
ERROR CODE : E : 0A
Detective details:
When Outdoor Temperature Thermistor open or short-circuit is
detected at power ON or while running the compressor.
-20°C -10°C -5°C
115 62.3 46.6
30°C
40°C 50°C
7.97 5.18 3.45
1 2
1 2 1 2
CN23 CN26
: No LED
0°C 5°C 10°C
35.2 26.9 20.7
60°C 70°C
2.36 1.65
1 2
CN25
07-10
15°C 20°C
16.1 12.6