Midea MCH2U-18PHH2 Service Manual page 58

8.4.2.2 E2(Communication malfunction between indoor and outdoor units) diagnosis and solution.
Error Code
Malfunction
conditions
Potential causes
Trouble shooting:
E2
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.
● Wiring mistake
● Faulty Indoor or outdoor PCB
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