Fujitsu ASYA07LGC Service Instruction page 47

Self - diagnosis function and Checking points
Error Indication
Error
Operation Timer
(Protection)
(GREEN) (ORANGE)
0.5 sec 0.5 sec Discharge thermistor error
3 times 2 times
0.5 sec Outdoor heat exchanger
3 times thermistor error
0.5 sec Outdoor temperature ther-
4 times mistor error
0.5 sec 0.5 sec Forced auto switch error
4 times 2 times
0.5 sec Main relay error
3 times
The detection value of the discharge thermistor is either open or shorted.
> Compressor, outdoor fan : OFF (It automatically releases when the normal value is detected.)
[Diagnosis Point]
Check thermistor resistance value (Refer to "Themistor characteristics table").
Controller PCB defective.
The detection value of the outdoor heat exchanger thermistor is either open or shorted.
> Compressor, outdoor fan : OFF (It automatically releases when the normal value is detected.)
[Diagnosis Point]
Check thermistor resistance value (Refer to "Themistor characteristics table").
Controller PCB defective.
The detection value of the outdoor temperature thermistor is either open or shorted.
> Compressor, outdoor fan : OFF (It automatically releases when the normal value is detected.)
[Diagnosis Point]
Check thermistor resistance value (Refer to "Themistor characteristics table").
Controller PCB defective.
Forced auto switch becomes ON for 30 consecutive seconds.
> It indicates the error but the operation continues.
[Diagnosis Point]
Check if forced auto switch is kept pressed.
Forced auto switch defective.
Controller PCB defective.
After 2 minutes 20 seconds of stopping operation, the signal from outdoor unit is received even though the main relay is OFF.
> Main relay OFF continues (outdoor unit OFF command)
[Diagnosis Point]
Main relay defective
Controller PCB defective.
Diagnosis Method