190-02207-A2
GPS 175/GNX 375/GNC 355 Part 23 AML STC Maintenance Manual
Rev. 3
Page 5-12
Figure 5-6 XPDR Alert Troubleshooting
Sheet 1 of 5
GNX 375 XPDR Alert
Messages
If fault still exists,
contact Garmin.
Transponder
Or
1090 ADS-B
Out
1090 MHz
Transmitter Failure
1030 MHz
Receiver Failure
Failure
ICAO Address
Failure
- Loss, damaged,
incorrect wiring
- Incorrect antenna
- Internal failure
ICAO address is
incorrect
Cause
Verify transponder
antenna,
connections, and
coax installation
Inspect wiring
Reload software
Reset config and
Reconfigure unit
Verify transponder
antenna,
connections, and
coax installation
Inspect wiring
Reload software
Reset config and
Reconfigure unit
Enter proper ICAO
address.
Reload software
Corrective
Action
Transponder
Or
1090 ADS-B
Out
Failure
Cause
- Loss, damaged,
incorrect wiring
- Incorrect antenna
- Internal failure
Corrective
Action
Transponder
Or
1090 ADS-B
Out
Failure
Cause
Corrective
Action
Reset config and
reconfigure unit
Frequency Lock
Failure
FPGA has an error
Possible internal
hardware issue
Reload software
Reset config and
reconfigure unit
Verify transponder
antenna,
connections, and
coax installation
Inspect wiring and
connections
Transponder
Or
1090 ADS-B
Out
Failure
Cause
Corrective
Action
High Temperature
Failure
Internal
Temperature has
exceeded limits,
possible internal
damage may have
occurred
Bring the GNX 375
within operating
temperature as
described in the
Temperature
diagnostics page.
See Section
3.4.4.13.
Transponder
Or
1090 ADS-B
Out
Failure
Cause
Corrective
Action
Low Temperature
Failure
Bring the GNX 375
within operating
temperature as
described in the
Temperature
diagnostics page.
See Section
3.4.4.13.
Internal
Temperature has
exceeded limits,
possible internal
damage may have
occurred
Transponder
Or
1090 ADS-B
Out
Failure
Cause
Corrective
Action
RAM Failure
Software load
issue or internal
hardware issue
Reload software
Transponder
Or
1090 ADS-B
Out
Failure
Cause
Corrective
Action
Reset config and
reconfigure unit
Squitter Monitor
Failure
Error generating
Squitter replies
Possible internal
hardware issue
Reload software
Reset config
Reconfigure unit
Verify transponder
antenna,
connections, and
coax installation
Inspect wiring and
connections
Transponder
Or
1090 ADS-B
Out
Failure
Cause
Corrective
Action