Fujitsu AS*G09LTCB Service Instructions Manual page 45

Trouble shooting 14
OUTDOOR UNIT Error Method:
Outdoor thermistor error
Detective Actuators:
Outdoor unit Main PCB
Outdoor temperature thermistor
Forecast of Cause :
1. Connector connection 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)
AO*G09/ 12LTCN
THERMISTOR
(PIPE)
BLACK
BLACK
BROWN
BROWN
THERMISTOR
(DISCHARGE)
THERMISTOR
(OUTDOOR)
BLACK
BLACK
If the voltage does not appear, replace Main PCB.
Indicate or Display:
Refer to error code table.
Detective details:
When Outdoor temperature thermistor open or short-circuit is
detected at power ON or while running the compressor.
2.Thermistor failure
-30°C -25°C -20°C -15°C
224.3 159.7 115.2 84.2
15°C 20°C 25°C 30°C
16.1 12.6 10.0 8.0
AO*G14LTCN
THERMISTOR
(PIPE)
1 1
2 2
CN71
3 3
4 4
THERMISTOR
(DISCHARGE)
THERMISTOR
(OUTDOOR)
1 1
CN70
2 2
3 3
3. Main PCB failure
-10°C -5°C 0°C
62.3 46.6 35.2
35°C 40°C 45°C
6.4 5.2 4.2
BLACK
1 1
BLACK
2 2
CN61
BLACK
3 3
BLACK
4 4
BLACK
1 1
CN62
2 2
BLACK
3 3
02-18
5°C 10°C
26.9 20.7
50°C 55°C
3.5 2.8