Transmission Error Between Indoor And Outdoor Units In The Same System - Daikin VRV IV-S RXTQ-TAVJU Series Service Manual

Troubleshooting by Error Code
4.44 Transmission Error between Indoor and Outdoor Units in
the Same System
U9
Error Code
Applicable All indoor units
Models
Method of Error Error signal for the other indoor units is detected within the system by outdoor unit PCB.
Detection
Error Decision
The error decision is made on any other indoor unit within the system concerned.
Conditions
Supposed
Causes
Troubleshooting
199
Transmission error within or outside of other system
Defective electronic expansion valve in indoor unit of other system
Defective PCB of indoor unit in other system
Improper connection of transmission wiring between indoor and outdoor unit
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
Turn ON all indoor units.
All the units are
U9
indicating .
YES
U9
has been
displayed for 2 minutes
or more.
YES
NO
NO
SiUS331604E
Continue the operation.
Re-diagnose by display after
passage of 2 minutes or more.
The indoor unit PCB indicated by
U9
the error code is normal.
Check for the indoor unit of other
system, and then conduct
troubleshooting by diagnosis
according to the Error Code
Flowchart.
Service Diagnosis