Table 5-4 Gps/Sbas Alert Troubleshooting Guide - Garmin GTN Xi Series Maintenance Manual

5.3.1.2 GPS/SBAS Related Alerts

Table 5-4 GPS/SBAS Alert Troubleshooting Guide

Alert Text
GPS RECEIVER -
GPS receiver has
failed. Check GPS
coaxial for electrical
short.
GPS RECEIVER -
GPS receiver needs
service.
LOSS OF
INTEGRITY (LOI) -
Verify GPS position
with other navigation
equipment.
GPS NAVIGATION
LOST - Insufficient
satellites. Use other
navigation source.
GPS NAVIGATION
LOST - Erroneous
position. Use other
navigation source.
GPS RECEIVER -
Low internal clock
battery.
MARK ON TARGET -
Waypoint creation
has failed. MOT
requires GPS
position.
SEARCHING SKY -
Search-the-sky in
progress.
190-01007-C1
Rev. 1
Possible Cause
A failure has been detected
in the GPS/SBAS receiver.
GPS antenna cable may be
shorted to ground.
The GTN Xi has detected an
internal failure in the GPS/
SBAS receiver.
Improper antenna installation
or coaxial routing.
Antenna shaded from
satellites.
RF interference at
1575.42 MHz from VHF
COM.
There is no GPS fix available
or the system is in Dead
Reckoning mode.
An internal position warning
has occurred.
The GTN Xi has detected a
low battery. Almanac data
may have been lost.
Mark on target waypoint
creation has failed because
of missing GPS position.
The GTN Xi is searching the
sky for GPS satellites.
Corrective Action
Verify that the center conductor is not shorted
to the braid in the coaxial cable.
Contact Garmin technical support for
assistance.
Contact Garmin technical support.
Check GPS antenna installation, connections,
and cable routing. The GPS antenna must be
mounted on top of the aircraft.
Make sure the aircraft is clear of hangars,
buildings, trees, etc.
Move GPS antenna further from the COM
antenna.
Add a 1575.42 MHz notch filter in COM
coaxial.
Fix or replace the COM.
Disconnect the ELT antenna coaxial to check
for possible re-radiation.
Wait for GPS satellite geometry to improve.
Ensure the aircraft has a clear view of the sky.
RAIM has determined that the info from one or
more GPS satellites may be in error.
Ensure the aircraft has a clear view of the sky.
Replace the battery.
Wait for GPS satellite geometry to improve.
Ensure the aircraft has a clear view of the sky.
Re-attempt waypoint creation.
Wait 20 minutes for the unit to complete the
cycle or until the current position is located.
GTN Xi Part 23 AML STC Maintenance Manual
Page 5-13