94 
15.5.28  F99 (DC Peak Detection) 
Malfunction Decision Conditions 
During startup and operation of cooling and heating, when inverter DC peak data is received by the outdoor internal 
DC Peak sensing circuitry. 
 
Malfunction Caused 
  DC current peak due to compressor failure. 
  DC current peak due to defective power transistor(s). 
  DC current peak due to defective outdoor unit PCB. 
  DC current peak due to short circuit. 
 
Troubleshooting 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
For safety reason and to prevent component
breakdown, always switch off the power 
before remove and connect the component.
Outdoor electronic circuit defect due to 
power transistor short.
Excessive amount of refrigerant.
Replace the outdoor unit PCB.
Compressor defective due to 
mechanical locked.
Replace compressor.
Compressor defective due to winding 
shorted.
Replace compressor.
Amplification IC defect.
Diode defect.
Defect in microcontroller.
Replace the outdoor unit PCB.
When abonormality indication starts again.
Reset the error code and turn on the unit 
again.
Is there no change even if all refrigerant 
is discharged?
Are the compressor’s winding resistance 
(U-V, V-W or U-W) shorted?
Is there a sound when compressor starts?
Is compressor vibration even?
YES
YES
YES
Turn off the power and disconnect 
the harnesses U, V and W.
Measure the winding resistance 
between U-V, V-W and W-U.
Check the compressor winding resistance:
NO (Compressor stops)
NO (Normal)
NO (Normal)
NO (Quite a lot of vibration at 
start operation)
YES (Stops after 2, 3 seconds 
of noise during operation)
Caution