Communication malfunction between
IPM board and outdoor main board
Is there at least one LED in
the IPM board light?
Check the signal wire
between the IPM board and
the main board
, is it
connected good?
Reconnect and retry. Is error
still display?
Replace IPM board, and then
check whether the system
can run normally
Replace the electric control
box
No
No
No
No
Yes
Trouble is solved
No
Yes
Replace outdoor main board,
and then check whether the
system can run normally
No
Yes
Yes