Midea MISSION2 3D INVERTER Series, Service Manual

Page: 91 / 113

Tr
oubleshooting
 Page 87 
5.3 E1 (Indoor and outdoor unit communication error)
Description : The indoor unit has not received feedback from the outdoor unit for 150 seconds, four consecutive times.
Recommended parts to prepare:
• Indoor PCB
• Outdoor PCB
• Reactor
Troubleshooting and repair:
Power off, then restart the unit after 2 minutes.
Does a problem remain? The unit is operating normally NO
Measure Vs. (Vs is the voltage between S and N of
outdoor unit. Red pan-S, Black pan-N)
YES
Is the voltage moving
alternately between Positive and
negative?
Check the outdoor wiring connection.
Is it normal?
Check the reactor.
YES
Is it normal?
Replace the outdoor PCB.
Power on.
YES
Is the error
resolved?
Replace the indoor PCB.
NO
Replace the
reactor
NO
Check the indoor wiring
connections
Is it normal?
Replace the indoor PCB.
Power on.
YES
Is the error resolved?
Replace the outdoor PCB.
NO
The voltage moves alternately with
positive value.
NO
The voltage is a
certain value
NO