Midea VRF V4 Plus I Series - E2: Indoor Units and Master Unit Communication Error

R410A DC Inverter V4 Plus 50Hz MCAC-VTSM-2014-04
96 Troubleshooting
5.3 E2: Indoor units and master unit communication error (Only display on master unit, all the ODU
in standby)
E2: Indoor units and master
unit communication error
Signal wires P, Q, E are short circuit or
disconnected (Measure the resistance
among P, Q and E, the normal
resistance is 120Ω)
Reconnect the signal wires
Signal wires are not connected in
series
The signal wires are interfered by high
voltage power (voltage over 220V is
high voltage power)
Signal wires are close to
electromagnetic interference source.
Such as transfer, strong fluorescent
lamp, etc.
Remove the interference source, or
use device to filter out the interference
The length of communication wire is
over 1200m
Adjust the wire length to less than
1200m or strengthen the signal
MC9S08AC128 chip is disabled
Main board is disabled
Replace main board
No
Yes
Yes
Yes
Yes
Connect the signal wires in line
shape
No
No
No
No
No
Yes
Ensure the signal wires and high
voltage wires do not twining
Yes