190-01007-A1
System Maintenance Manual GTN 6XX/7XX Part 23 AML STC
Rev. 5
Page 5-15
5.3.1.7 Datalink Related Alerts
Table 5-9. Database Alert Troubleshooting Guide
Alert Text
Possible Cause
Corrective Action
DATALINK – GDL 69 is
inoperative or connection to
GTN is lost.
The GTN cannot communicate
with the GDL 69.
Check for proper configuration.
Ensure the GDL 69 is powered
up.
Verify that the GDL 69
Ethernet ports are enabled.
HSDB data from the GDL 69
can be routed to the GTN
through other Garmin LRUs.
Ensure that all Garmin LRUs
are powered up.
DATALINK – GDL 88 is
inoperative or connection to
GTN is lost.
The GTN cannot communicate
with the GDL 88.
Check for proper configuration.
Ensure the GDL 88 is powered
up.
HSDB data from the GDL 69
can be routed to the GTN
through other Garmin LRUs.
Ensure that all Garmin LRUs
are powered up.
DATALINK - GDL 88 ADS-B
failure. Unable to transmit
ADS-B messages.
GDL 88 is not able to transmit
an ADS-B message due to a
failure with the GDL 88 system
or antenna(s).
Check the GDL 88 Fault page
in configuration mode on the
GTN.
Refer to the GDL 88 STC
Installation Manual.
DATALINK – GDL 88 ADS-B
fault.
The GDL 88 has detected a
fault with one of the GDL 88
UAT/1090 antennas.
Refer to the GDL 88 STC
Installation Manual.
DATALINK – ADS-B fault: UAT
receiver.
The GDL 88 has detected a
UAT receiver fault.
Refer to the GDL 88 STC
Installation Manual.
DATALINK – ADS-B fault:
1090 receiver.
The GDL 88 has detected a
1090 receiver fault.
Refer to the GDL 88 STC
Installation Manual.
DATALINK - GDL 88 ADS-B is
not transmitting position.
Check GPS devices.
The GDL 88 has detected a
position input fault.
Refer to the GDL 88 STC
Installation Manual.
DATALINK - GDL 88 control
panel input fault. Check
transponder is in correct mode.
The GDL 88 has lost
communication with the
transponder.
Refer to the GDL 88 STC
Installation Manual.
DATALINK - GDL 88 ADS-B
fault. Pressure altitude input is
invalid.
The GDL 88 has lost
communication with the
pressure altitude source.
Refer to the GDL 88 STC
Installation Manual.
DATALINK - GDL 88 ADS-B
traffic has failed.
GDL 88 may have lost GPS
position.
The GDL 88 has detected an
internal failure.
Check the GDL 88 Fault page
in configuration mode on the
GTN.
Refer to the GDL 88 STC
Installation Manual.
