Fujitsu AUXB04GALH Service Manual page 123

Trouble shooting 45
OUTDOOR UNIT Error Method:
Suction Gas Temp Sensor Error
<TH4>
Detective Actuators:
Suction gas temperature thermistor
Forecast of Cause :
1. Connector connection defective, open
2. Thermistor defective
3. Main PCB defective
Check Point 1 : Check the connector connection and cable open
Connector connection state check
Cable open check
OK
Check Point 2 : Check the thermistor
Thermistor characteristics check (Disconnect the thermistor from the PCB and check.)
* For the thermistor characteristics, refer to the "Service Parts Information 17".
OK
Check Point 3 : Check voltage of Main PCB (DC5.0V)
Main PCB (CN147:1-2) voltage value = 5V
Remove the thermistor from Main PCB, check the voltage.
CN147
Suction gas temperature sensor (CN147:1-2)
If the voltage does not appear, replace Main PCB and set up orignal address.
Indicate or Display:
E. 75.1
Outdoor Unit : E. 75. 1
Error Code
Detective details:
Suction gas temperature thermistor short or open detected
1 2 3 4
1 2 3 4
Filter LED Continuous Flash.
: 75
DC
04-53