190-02246-11
GI 275 Part 23 AML STC Maintenance Manual
Rev. 1
Page 4-30
Figure 4-22 NAV Alert Message Troubleshooting
NAV/GPS Alert
Messages
If fault persists,
contact Garmin.
NAV <1/2>
inoperative
Maintenance
Log Message
NAV <1/2> interface/unit
failed. Check NAV unit or
wiring.
Cause
NAV source has lost
communication
NAV source is
reporting failed
Corrective
Action
Corrective
Action
Verify NAV source
is on and not
reporting failed
Troubleshoot in
accordance with
NAV unit
maintenance
manual
Verify configuration
settings
Inspect NAV wiring
and connections
Verify configuration
settings
Inspect NAV wiring
and connections
Navigation
database mismatch
Maintenance
Log Message
Navigation
database mismatch
Cause
Multiple GI 275 units
have different NAV
database expirations
Corrective
Action
Update databases
across all units to
the same date
Navigation database not
yet effective
Maintenance
Log Message
Navigation
database not yet
effective
Cause
Preloaded database
is not activated on
the system
Corrective
Action
Activate databases:
Follow system
prompts
Navigation
database expired
Maintenance
Log Message
Navigation
database expired
Cause
Navigation
database has
expired
Corrective
Action
Update to the
current database
version
GPS <1/2>
inoperative
Maintenance
Log Message
GPS <1/2> interface
failed
Cause
GPS source has
lost communication
GPS source is
reporting failed
Corrective
Action
Verify GPS source is ON and
has a clear view of the sky
Verify configuration settings
Inspect GPS antenna, wiring
and connections
