Troubleshooting by Error Codes SiUS281811EA
282 Part 6 Service Diagnosis
4.51 Transmission Error between Remote Controller and
Indoor Unit
Error Code U5
Applicable
Models
All indoor units
Method of Error
Detection
In case of controlling with 2 remote controllers, check the system using microcomputer if signal
transmission between indoor unit and remote controller (main and sub) is normal.
Error Decision
Conditions
Normal transmission does not continue for specified period.
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
Defective transmission caused by noise
Troubleshooting
Refer to page 90 for Main/Sub setting.
Control by 2
remote controllers
Main/Sub
setting of both
remote controllers is set
to Main.
All indoor unit
PCB microcomputer
normal monitors
blinking
Resets
normally when
power supply is turned OFF
temporarily.
NO
NO
NO
YES
NO
Replace the indoor unit
PCB.
Set one of the remote
controllers to Sub, turn OFF
the power supply temporarily,
then restart operation.
The error could be produced by
noise. Check the surrounding
area and restart operation.
The error could be produced by
noise. Check the surrounding
area and restart operation. (Ex.:
Heavy-duty wireless equipment,
etc.)
Normal.
Normal.
NO
NO
YES
YES
YES
Replace the remote controller
and restart operation.
YES
Replace the indoor unit PCB
and restart operation.
Is operation normal?
Is operation normal?
YES
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
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