Fujitsu AUXG07KVLA Service Manual page 236

2-4. E: 18. External communication error (Indoor unit)
Indicator Indoor unit
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 WAN 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 WLAN adapter and the main PCB (If there is loose con-
nector, open cable or mis-wiring.)
Check point 2. Replace the WLAN adapter
If check point 1 do not improve the symptom, change WLAN adapter.
Check point 3. Replace the main PCB
If check point 2 do not improve the symptom, replace the main PCB.
2-4. E: 18. External communication error (Indoor unit)
Operation indicator
Timer indicator
Economy indicator
Error code
External
communication
error
↓
↓
↓
End
Continuous flash
After receiving a signal from the external input and
output PCB, the same signal has not been received for
15 seconds.
Connection failure
WLAN adapter failure
- (03-20) -
1 time flash
8 time flash
E: 18
Main PCB
2. Troubleshooting with error code