SiSG121917E
Troubleshooting for MSP Duct Type Indoor Unit
Part 6 Service Diagnosis
136
6.9 Signal Transmission Error (Between MAIN Remote
Controller and SUB Remote Controller)
Error Code
U8
Method of Error
Detection
In case of controlling with 2 remote controllers, check the system using microcomputer if signal
transmission between MAIN remote controller and SUB remote controller is normal.
Error Decision
Conditions
Normal transmission does not continue for specified period.
Supposed
Causes
Remote controller is set to SUB when using 1 remote controller
Connection of 2 SUB remote controllers (when using 2 remote controllers)
Defective remote controller PCB
Troubleshooting
Is SS1
of remote
controller PCB set to
SUB?
T
u
rn the po
w
er off and then
b
ack on. If a malf
u
nction occ
u
rs,
replace the remote controller
PCB.
T
u
rn the po
w
er off and then
b
ack on. If a malf
u
nction occ
u
rs,
replace the remote controller
PCB.
Set one remote controller to
MAI
N
; t
u
rn the po
w
er s
u
pply off
once and then
b
ack on.
Set SS1 to MAI
N
; t
u
rn the
po
w
er s
u
pply off once and then
b
ack on.
YES
N
O
YES
N
O
N
O
YES
(R21113)
Using 2 remote
controllers?
Is SS1 of
b
oth
remote controllers
set to SUB?
Caution
Be s
u
re to t
u
rn off the po
w
er s
w
itch
b
efore connecting or disconnecting
connectors, or parts may
b
e damaged.