Communication malfunction between indoor and 
outdoor units
Start: Power off , then Power on the 
A/C by the Breaker. (reconnect the 
power wire). Is it still displaying the 
error code?
Yes
No
Change outdoor unit PCB assembly(include 
wiring) totally
Check wiring on the outdoor and indoor 
terminal follow the wiring diagram. Is all 
connecting correctly?
Yes
No
Measure Vs, is it moving 
alternately between positive value 
and negative value? (Vs is the 
voltage between S and L2). Refer 
PIC 1
Turn on all indoor unit by remote 
controller. Is all indoor unit display
Turn off the all indoor units. Is IPM 
power LED or operating LED  lamp 
On? Refer PIC2
Yes
A: Is all the wiring between 
terminal and Indoor PCB 
connect ok?
No
Yes
A
No
Reconnect the wiring
Is indoor units number correct? Check 
on the outdoor check point . (2 for dual 
zone, 3 for tri zone, 4 for qua zone). 
Refer PIC 4.
Yes
No first time
Yes
Yes
Change the Indoor PCB
Power on by remote 
controller, IIs it still 
displaying the error code 
after 3 minutes?
Trouble is solved
No second time
No
Yes
Reconnect the wiring
No
change IPM
No
Is the reactor connecting 
well?
No Reconnect the wiring
Change Outdoor Main PCB
Yes
No
Is main board“       ” 
lamp on? Refer PIC 3.