Fujitsu AS*G09KXCA Series Service Instruction page 44

Trouble shooting 7
INDOOR UNIT Error Method:
Indoor Room Thermistor Error
Detective Actuators:
Indoor unit Controller PCB
Room temperature thermistor
Forecast of Cause : 1. Connector failure connection 2. Thermistor failure 3. Controller PCB failuer
Check Point 1 : Check connection of Connector
Check if connector is loose or removed
Check erroneous connection
Check if thermistor cable is open
>>Reset Power when reinstalling due to removed connector or incorrect wiring.
OK
Check Point 2 : Remove connector and check Thermistor resistance value
Thermistor Characteristics (Rough value)
Temperature (°C )
Resistance value (k )
Temperature (°C )
Resistance value (k )
If Thermistor is either open or shorted, replace it and reset the power.
OK
Check Point 3 : Check voltage of Controller PCB (DC5.0V)
Make sure circuit diagram of each indoor unit and check terminal voltage at Thermistor (DC5.0V)
BLACK
1 1
CN4
BLACK
2 2
If the voltage does not appear, replace Controller PCB and execute the check operation again.
Indicate or Display:
Indoor Unit :
Operation indicator : 4 time Flash
Timer indicator
Economy indicator: Continuous Flash
Error code: [ E: 41 ]
Detective details:
When Room temperature thermistor open or short-circuit is detected.
-10 -5 0
58.3 44.0 33.6
30 35 40
8.0 6.5
5.3
Thermistor(Room Termp.)
: 1 time Flash
5 10 15
25.9 20.2 15.8 12.5
45
4.4
02-11
20 25
10.0
DC