E: 18.↓. External Communication Error (Indoor Unit) - Fujitsu AUUH18LUAS Service Manual

2-5. E: 18.X. External communication error (Indoor unit)
→ired remote
Indicator
controller
Detective actuator Indoor unit
Forecast of cause
Check point 1. Check the connection
• Check any loose or removed connection between the main PCB to the →LAN Adapter.
-> If there is an abnormal condition, correct it by refer to the installation manual or the "DESIGN
& TECHNICAL MANUAL".
• Check the connection condition on the →LAN Adapter and the main PCB (If there is loose con-
nector, open cable or mis-wiring.)
Check point 2. Replace the →LAN Adapter
If check point 1 do not improve the symptom, change →LAN Adapter.
Check point 3. Replace the main PCB
If check point 2 do not improve the symptom, replace the main PCB.
2-5. E: 18.↓. External communication error (Indoor unit)
Error code
External
communication
error
End
After receiving a signal from the external input and
output PCB, the same signal has not been received for
15 seconds.
Connection failure
→LAN Adapter failure
- (03-11) -
E: 18
Main PCB
2. Troubleshooting with error code