Check code
Abnormal points and detection methods
Causes and checkpoints
If serial communication between the outdoor controller board and outdoor
power board is defective.
Wire breakage or contact failure of connector CN2 or
CN4
Malfunction of power board communication circuit on
outdoor controller board
Malfunction of communication circuit on outdoor
power board
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Diagnosis
Remedy
Serial communication error
0403
(Ed)
No
No
Yes
Yes
44
OCH675E
8-1-3. SELF-DIAGNOSIS ACTION BY FLOWCHART
Are they connected normally?
Are they connected normally?
Check the connection of the communication
line (CN2 and CN4) between the outdoor
controller board and power board.
Check the wiring.
Connect the CN2 and CN4 properly.
Replace them in the case of breakage.
Connect the wiring properly.
Replace them in the case of breakage.
The communication circuit of either the
outdoor controller board or power board is
defective.
If unable to identify the defective circuit;
Replace the outdoor controller board if it
does not recover.
Replace the outdoor power board.