190-02207-A2
GPS 175/GNX 375/GNC 355 Part 23 AML STC Maintenance Manual
Rev. 3
Page 5-10
Figure 5-4 GPS 175/GNC 355 Traffic Alert Troubleshooting
ADS-B traffic
alerting function
inoperative.
ADS-B traffic
function
inoperative.
Traffic/FIS-B
functions
inoperative.
1090ES traffic
receiver fault.
ADS-B fault –
GDL 88 needs
service.
GPS 175/GNC 355 Traffic Alerts
Cause
ADS-B failure.
Unable to transmit
ADS-B messages.
GDL 88
configuration
module needs
service.
Corrective
Action
Cause
Cause
Cause
Cause
Cause
The GDL 88/GTX
345 is reporting a
CSA or TSAA/
ATAS failure.
The GDL 88/GTX
345 is reporting
that ADS-B Traffic
In has failed.
Check for proper
configuration of
the transponder
interface.
Electrical fault,
calibration data
fault,
SW CRC Fault, or
FPGA Fault.
1090 receiver has
failed.
Fan Fault, Low
Battery, Bottom/
Top Antenna Fault
Corrective
Action
Corrective
Action
Improper
configuration or
wiring.
Ensure the aircraft
has a clear view of
the sky.
Corrective
Action
Refer to
transponder
installation
manual.
If faults still exist,
contact Garmin.
Corrective
Action
Corrective
Action
GDL 88 cannot
communicate with
its configuration
module.
Corrective
Action
Refer to GDL 88
installation
manual.
ADS-B Out fault.
Check
transponder is in
correct mode.
Check that the
transponder is in
correct mode.
Corrective
Action
Cause
Maintenance
Log Message
Communications
with the GDL 88/
GTX 345 has
been lost.
The GDL 88/GTX
345 reports traffic/
FIS-B functions
inoperative:
<condition>
Check for correct
wiring
Refer to
transponder
installation
manual.
Cause
GDL 88 control
panel input has
failed.
Refer to GDL 88
installation
manual.
Maintenance
Log Message
GDL 88 reports
ADS-B Out
fault. Check
transponder is in
correct mode.
Cause
ICAO Address
Fault, UAT
Transmitter Fault,
UAT Broadcast
Fault, Bottom/Top
Antenna Fault
Maintenance
Log Message
GDL 88 reports
ADS-B failure.
<condition>
Refer to GDL 88
installation
manual.
Maintenance
Log Message
GDL 88 reports
<condition>
Corrective
Action
Refer to GDL 88
installation
manual.
UAT traffic/FIS-B
receiver fault.
Cause
1090 receiver has
failed.
Corrective
Action
Refer to
transponder
installation
manual.
Maintenance
Log Message
GDL 88/GTX 345
reports 1090ES
traffic receiver
fault.
Maintenance
Log Message
GDL 88/GTX 345
reports UAT
traffic/FIS-B
receiver fault.
Refer to
transponder
installation
manual.
Maintenance
Log Message
GDL 88/GTX 345
reports ADS-B In
Traffic has failed.
Maintenance
Log Message
GDL 88/GTX 345
reports ADS-B
traffic alerting
function
inoperative.
Refer to
transponder
installation
manual.
Refer to
transponder
installation
manual.
