Garmin G900X Installation And Maintenance Manual page 561

D.6.8 GPS Related Alerts
Before troubleshooting, ensure that no cell phones or devices using cell phone
technology are turned on in the cabin (even in a monitoring state).
Message
GPS1 SERVICE – GPS1
needs service. Return unit for
repair.
GPS2 SERVICE – GPS2
needs service. Return unit for
repair.
GPS1 FAIL – GPS1 is
inoperative.
GPS2 FAIL – GPS2 is
inoperative.
GPS NAV LOST – Loss of
GPS navigation. GPS fail.
G900X/G950 Installation and Maintenance Manual – Troubleshooting
190-00719-00
NOTE
Cause
The System has detected
a failure in GPS1 receiver.
The system has detected
a failure in GPS2 receiver.
The system has detected
a failure in GPS1 receiver.
The system has detected
a failure in GPS2 receiver.
The system has lost GPS
navigation information.
Solutions
•
Replace GIA1.
•
Replace GIA2.
•
Switch GIA1 and GIA2, to verify
location of problem:
−
If problem follows the unit,
replace GIA1.
−
If problem does not follow the
unit, check GPS1 antenna and
cabling.
•
Switch GIA1 and GIA2, to verify
location of problem:
−
If problem follows the unit,
replace GIA2.
−
If problem does not follow the
unit, check GPS2 antenna and
cabling.
•
Verify the area the aircraft was
traveling through did not have loss
of GPS coverage. FAA NOTAMs
may be issued for periods of
outages, or the US Coast Guard
website
http://www.navcen.uscg.gov/gps/gps
notices/default.htm
posted.
•
Using the MFD AUX – GPS Status
page, verify the signal strength bars
are not erratic. If so, this indicates
outside interference is affecting the
GPS receivers. Find and remove
the source of interference (i.e. cell
phones, FBO datalink antennas,
etc.).
•
Check GPS antenna and cabling.
will have notices
Page D-49
Revision D