U5" Malfunction Of Transmission Between Indoor Unit And Remote Controller - Daikin SkyAir Service Manual

Troubleshooting by Remote Controller Display / LED Display
5.41 "U5" Malfunction of Transmission between Indoor Unit
and Remote Controller
U5
Remote
Controller
Display
Applicable All models of indoor units
Models
Error generation The error is generated when the microprocessor detects that the transmission between the
indoor unit and the remote controller is not normal over a certain amount of time.
Supposed The possible causes are:
Causes
Troubleshooting
220
Malfunctioning remote controller
Malfunctioning indoor PC board
Outside cause (noise...)
Connection of two master remote controllers (when using two remote controllers).
Be sure to turn off power switch before connect or disconnect connector,
Caution
or parts damage may be occurred.
Control by 2 remote
controllers
NO
All
indoor unit
PCB microcomputer
normal monitors
flashing
YES
Using
multicore
transmission wiring
between indoor unit
and remote
controller
NO
Is "U5" displayed
constantly?
YES
SS1 of both
YES
remote controllers is
set to MAIN.
Resets
normally when
NO
power supply is turned
off temporarily.
YES
YES
NO
SiBE28-804
YES
Set one of the remote
controllers to SUB, turn
off the power supply
temporarily, then restart
operation.
NO
Indoor unit PC board
replacement.
Malfunction could be
produced by noise.
Check the surrounding
area and restart
operation.
Change to
double-core
independent cable.
Failure of remote
controller PC board or
replacement of defective
indoor unit PC board.
Problem could be
caused by external
factor (noise etc.) other
than malfunction.
Troubleshooting