SiUS30-1301
Troubleshooting by Indication on the Remote Controller
Service Diagnosis
221
3.42 Transmission Error between Remote Controller and
Indoor Unit
Error Code
U5
Applicable
Models
All indoor models
Method of Error
Detection
Micro-computer checks if transmission between indoor unit and remote controller is normal.
Error Decision
Conditions
When transmission is not carried out normally for a certain amount of time
Supposed
Causes
Transmission error between indoor unit and remote controller
Connection of 2 main remote controllers (when using 2 remote controllers)
Defective indoor unit PCB
Defective remote controller PCB
Transmission error caused by noise
Troubleshooting
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Operation
returns to normal when
the power is turned OFF
momentarily.
NO
NO
NO
YES
NO
Replace the indoor unit
PCB.
Set one remote controller to
"Sub"; turn OFF the power
supply and then turn the
power ON.
There is possibility of error
caused by noise. Check the
surrounding area and turn ON
again.
The indoor unit PCB is
normal.
There is possibility of error
caused by noise. Check the
surrounding area and turn ON
again.
Normal
Normal
NO
NO
Using 2-
remote controllers
control.
SS1 of both
remote controllers is set
to "MAIN."
All indoor
unit PCB micro-
computer monitors
blink.
YES
YES
YES
Replace the remote controller.
Is it normal?
YES
Replace the indoor unit PCB.
Is it normal?
YES