Service Manual

Troubleshooting by Error Codes SiUS281811E
258 Part 6 Service Diagnosis
Reference
4.57 Transmission Error between Centralized Controller and
Indoor Unit
Error Code UE
Applicable
Models
All indoor units
Centralized controller
Method of Error
Detection
Microcomputer checks if transmission between indoor unit and centralized controller is normal.
Error Decision
Conditions
When transmission is not carried out normally for a certain amount of time
Supposed
Causes
 Disconnection or error of transmission wiring
 Defective setting of group No. or address
 Transmission error between optional controllers for centralized control and indoor unit
 Defective PCB for centralized controller
 Defective indoor unit PCB
Troubleshooting
CHECK 15 Refer to page 274.
Has an
indoor unit once
connected been removed
or its address
changed?
Is
transmission
wiring disconnected or
wired incorrectly?
Is
transmission with
all indoor units
error?
Is the
transmission
wiring with the main
controller disconnected or
wired incorrectly?
Is the main
controller's connector
for setting main controller
disconnected?
Is the
group No. of error
indoor units set?
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Set the group No.
correctly.
Replace the indoor unit
PCB.
Fix the wiring correctly.
Fix the wiring correctly.
Connect the connector
correctly.
Replace the indoor unit
PCB.
Reset power supply
simultaneously for all optional
centralized control equipment.
NO
YES
NO
YES
NO
NO
YES
NO
YES
YES
YES
NO