Gree GMV-VQ680WM/C-X Service Manual page 200

Gree
2.149 "o9" IDU main control communication error
Error display: ODU main board and IDU wired controller will display
Applicable model: multi VRF IDU with DC motor
Error judgment condition and method:
If the main control does not receive data in 30 consecutive seconds, it will report communication error; if the
drive does not receive data in 30 consecutive seconds, it will report communication error.
Possible reasons:
■Poor contact between main control board and drive board communication terminal
■Detecting circuit is abnormal
Troubleshooting:
"o8" IDU drive
communication error
Check the terminal between
external drive board and main control
board to see if it is loose or any
foreign objects inside?
No
Detecting circuit might
be abnormal
Replace the drive board and
main control board to confirm
and replace the faulted board
GMV6 HR DC Inverter VRF Units Service Manual
If it is loosened or
Yes
there are foreign
objects, retighten it
after treatment
198