Toshiba MM-A0280HT Service Manual page 72

Diagnostic Procedure for Check Code
Check code
[98]
BUS communication alarm (2)
Is the wiring connection
of communication cables
to X,Y normal?
Yes
Is [98] displayed only
on the central controller?
Yes
Is [97] displayed only
on the central controller?
No
Check the central controller.
If defective, replace.
Troubleshooting
1. Miswiring of XY communication cables
2. Duplicated network addresses
3. Indoor P .C. board error, central controller error
No
No
Is connection of CN602
connector on interface
P .C. board of the master
outdoor unit normal?
Yes
Is there duplication
of network addresses?
No
Check indoor P .C. board.
If defective, replace.
Yes
73
Operation cause
Check connection of wiring.
Check communication cable
No
connection to slave units of
group operation.
Yes
Check duplication of network
addresses.
Check No. of connected
central controllers to 1 unit.
14