Service manual

ESIE03–01 Error Codes: System Malfunctions
Part 3 – Troubleshooting 3–67
3
3
4
5
1
4.5 Transmission Error between Indoor Unit and Remote Controller (U5)
Error code U5
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.
Causes The possible causes are:
P Malfunctioning remote controller
P Malfunctioning indoor PCB
P Outside cause (noise...)
P Connection of two master remote controllers (when using two remote controllers).
Troubleshooting To troubleshoot, proceed as follows:
Caution Be sure to turn off power switch before connecting or disconnecting the connector, or parts damage
may occur.
Set one of the
remote controllers
to SUB, turn off
the power supply
temporarily, then
restart operation.
Indoor unit PCB
replacement.
Malfunction could
be produced by
noise. Check the
surrounding area
and restart
operation.
Change to
double-core
independent
cable.
Failure of remote
controller PCB or
replacement of
defective indoor
unit PCB.
All indoor
unit PCB
microcomputer
normal monitors
flashing
Using
multicore
transmission wiring
between indoor unit
and remote
controller
Control by 2 remote
controllers
NO
YES
YES
YES
YES
Resets
normally when
power supply is turned
off temporarily.
NO
SS1 of both
remote controllers is
set to MAIN.
YES
NO NO