Fujitsu ARU7RLF Service Instruction page 59

Trouble shooting 20
OUTDOOR UNIT Error Method:
2-way valve Thermistor Error
Detective Actuators:
Outdoor Unit Main PCB Circuit
2-way valve 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(°F)
Resistance Value (k )
Temperature(°F)
Resistance Value (k )
If Thermistor is either open or shorted, replace it and reset the power.
OK OK
Check Point 3 : Check voltage of Main PCB (DC5.0V) Check Point 3 :
Make sure circuit diagram of outdoor unit and check terminal voltage at Thermistor (DC5.0V)
BLACK
1 1
1
WHITE RED
3
2 2
WHITE
4 3 3
WHITE YELLOW
5 4 4
CN39
WHITE
6 5 5
WHITE BLUE
6 6
7
WHITE
7
8 7
WHITE BLACK
9 8 8
WHITE
BLACK
1 1 1
RED GRAY
2 2 2
RED
4 3 3
RED BROWN
5 4 4
CN40
RED
6 5 5
RED ORANGE
7 6 6
RED
8 7 7
GREEN
RED
9 8 8
RED
If the voltage does not appear, replace Main PCB.
Indicate or Display:
Refer to error code table.
Detective details:
When 2-way valve Temperature Thermistor open or short-circuit is
detected at power ON or while running the compressor.
14°F 23°F 32°F
312 233 176
104°F
122°F 140°F
25.6 17.1 11.6
VALVE THERMISTOR A, B
2-WAY VALVE A
3-WAY VALVE A
2-WAY VALVE B
3-WAY VALVE B
VALVE THERMISTOR D (For AOU36RLXFZ)
2-WAY VALVE C
3-WAY VALVE C
2-WAY VALVE D
3-WAY VALVE D
41°F 50°F 59°F
134 103 80.3
158°F 176°F 194°F
8.12 5.78 4.19
02-24
68°F 86°F
62.9 39.6
212°F
3.09