Table 5-4. Gps/Sbas Alert Troubleshooting Guide - Garmin GTN 6 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.
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.
SEARCHING SKY -
Search-the-sky in
progress.
190-01007-A1
Rev. 6
Possible Cause
A failure has been detected
in the GPS/SBAS receiver.
GPS antenna cable may be
shorted to ground.
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 has detected a
low battery. Almanac data
may have been lost.
The GTN is searching the
sky for GPS satellites.
System Maintenance Manual GTN 6XX/7XX Part 23 AML STC
Corrective Action
Verify that the center conductor is not
shorted to the braid in the coaxial cable.
Contact Garmin technical support for
assistance.
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 20 minutes for the unit to complete the
cycle or until the current position is located.
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