Fujitsu AUXB04GALH Service Manual page 109

Trouble shooting 23
INDOOR UNIT Error Method:
Indoor unit Heat Ex. outlet temp.
Sensor Error
Detective Actuators:
Indoor Unit Controller PCB Circuit
Heat Exchanger Outlet Temp. Sensor
Forecast of Cause :
1. Connector defective connection
Check Point 1 : Check connection of Connector
Check if connector is loose or removed
Check erroneous connection
Check if Sensor cable is open
>>Reset Power when reinstalling due to removed connector or incorrect wiring.
OK
Check Point 2 : Remove connector and check sensor resistance value
Sensor Characteristics (Rough value)
Temperature (
°F)
Temperature ( °C)
Resistance Value (k )
Voltage Value (V)
Temperature ( °F)
Temperature ( °C)
Resistance Value (k )
Voltage Value (V)
If Thermistor is either open or shorted, replace it and reset the power.
OK
Check Point 3 : Check voltage of Controller PCB (DC5.0V)
Corresponding connector
Model Type
Duct type
Cassette type
Wall mounted type
Floor / Ceiling type
Compact Wall mounted type
If the voltage does not appear, replace Controller PCB and set up the original address.
Indicate or Display:
E42. 3
Outdoor Unit : E.5 U.1
Indoor Unit
Error Code
Detective details:
When open or shorted Heat Exchanger outlet temp. sensor is detected
2.Sensor defective
32 41 50
0 5 10
168.6 129.8 100.9
1.14 1.39 1.65
104 113 122
40 45 50
26.3 21.6 17.8
3.27 3.49 3.69
Heat Ex Outlet temp. Sensor
(Gray Wires)
CN9
CN21
: Operation LED 4 times Flash, Timer LED 2 Times Flash,
Filter LED Continuous Flash.
: 4 2
3.Controller PCB defective
59 68 77
15 20 25
79.1 62.5 49.8
1.93 2.22 2.50
04-33
86 95
30 35
40.0 32.4
2.77 3.03
DC