Midea MP09HMB82

10.2.2 Communication malfunction between main control board and display board. (E4)
Error Code
E4
Malfunction decision
conditions
Main control board does not receive feedback from display board
during 120 seconds.
Supposed causes
● Wiring mistake
● Faulty display board
● Faulty main control board
Troubleshooting:
www.mideaaircon.com 26
Communication malfunction between main
control board and display board
Check the signal wire between the
Display board and the main board,
is it connected good?
Reconnect and retry. Is error
still display?
Replace display board, Is error
still display?
Replace the main control
board
No
Yes
Yes
Trouble is solved
No
Yes
No