Midea M4OC-36HRFN1-M - Communication Malfunction (E2) Diagnosis

9.4.2.2 E2(Communication malfunction between indoor and outdoor units) error diagnosis and solution.
Error Code
E2
Malfunction decision
conditions
Indoor unit does not receive the feedback from outdoor unit
during 120 seconds or outdoor unit does not receive the
feedback from any one indoor unit during 180 seconds.
Supposed causes
● Wiring mistake
● Indoor or outdoor PCB faulty
Trouble shooting: