Carrier 38QUS014DS2-2 Service Manual page 73

18.3.1.2 Indoor / outdoor units communication error
Indoor / outdoor units communication error
Start: Power off , then Power on the
A/C by the Breaker. (reconnect the
power wire). Is it still displaying the
error code?
Yes
Check wiring on the outdoor and indoor
terminal follow the wiring diagram. Is all
connecting correctly?
Yes
Turn on all indoor unit by remote
controller. Is all indoor unit display
Yes
Turn off the all indoor units. Is IPM
power LED or operating LED lamp
On? Refer PIC2
Yes
Is main board"
lamp on? Refer PIC 3.
Yes
Is indoor units number correct? Check
on the outdoor check point . (2 for dual
zone, 3 for tri zone, 4 for qua zone,5 for
qui zone). Refer PIC 4.
No first time
Replacee outdoor unit PCB assembly(include
wiring) totally
No
alternately between positive value
No
voltage between S and N). Refer
Yes
Replace IPM board or
No
the outdoor main PCB
"
Is the reactor connecting
No
Replace the outdoor main PCB
No second time A
Reconnect the wiring
Reconnect the wiring
Measure Vs, is it moving
and negative value? (Vs is the
PIC 1
Yes
No Reconnect the wiring
well？
Yes
70
No
A:
Is all the wiring between
No
terminal and Indoor PCB
connect ok?
Yes
Replace the Indoor PCB
Power on by remote
controller, I Is it still
displaying the error code
after 3 minutes?
No
Trouble is solved
No