Fujitsu ARCG040LSTA Service Instruction page 48

Trouble shooting 20
OUTDOOR UNIT Error Method:
4-way valve error
Detective Actuators:
Indoor unit Controller PCB
Heat exchanger temperature thermistor
Room temperature thermistor
4-way valve
Forecast of Cause :
1. Connector connection failure
5. 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 : Check thermistor of Indoor unit
Isn't it fallen off the holder?
Is there a cable pinched?
>> Check characteristics of thermistor, (Refer to Trouble shooting 7,8),
If defective, replace the thermistor.
OK OK
Check Point 3 : Check the solenoid coil and 4-way valve
[ Solenoid coil ]
Remove CN30 from PCB and check the resistance value of coil.
Resistance value is about 1.4k
>> If it is Open or abnormal resistance value, replace Solenoid Coil.
[ 4-way valve ]
Check each piping temperature,
and the location of the valve by the temperature difference.
>> If the value location is not proper, replace 4-way valve.
OK OK
Check Point 4 : Check the voltage of 4-way valve
Check the CN 30 voltage of Main PCB
Check if AC198V(AC220V-10%) - 242V(AC220V+10%) appears at CN 30 of Main PCB.
[ Heating operation ]
>> If it is not voltage, Replace Main PCB.
[ Cooling operation ]
>> If it is voltage, Replace Main PCB.
OK OK
Check Point 5 : Replace Controller PCB
If Check Point 1- 4 do not improve the symptom, replace Controller PCB of Indoor unit .
Indicate or Display:
Outdoor Unit : No indication
Indoor Unit : Operation lamp: 9 time Flash, Timer lamp: 9 time Flash
Economy lamp : Continuous flash.
ERROR CODE : [E : 99]
Detective details:
When the indoor heat exchanger temperature is compared with
the room temperature, and either following condition is detected
continuously two times, the compressor stops.
Cooling or Dry operation
[Indoor heat exchanger temp.] - [Room temp.] > 10
Heating operation
[indoor heat exchanger temp.] - [Room temp.] < -10
If the same operation is repeated 5 times,
the compressor stops permanently.
2. Thermistor failure
6. Controller PCB failure
02-22
3. Coil failure 4. 4-way valve failure
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