G1000 Supplemental Maintenance Manual
Page 5-24
Textron Nav III Series
Revision 3
190-02128-04
GSU Alerts
Failure Message
Cause
Solutions
MANIFEST
– GRS software
mismatch. Communication
halted.
The system has detected an
incorrect software version loaded
in the specified GRS unit.
•
Load correct software version.
AHRS SERVICE
– AHRS
magnetic-field model needs
update.
The AHRS magnetic field model
should be updated for the
specified unit. Appears on ground
only.
•
Load updated AHRS magnetic field
file. See Section 4.5.
GEO LIMITS
– AHRS too far
north/south, no magnetic
compass.
No magnetic compass information
available due to being too far
north or south.
•
Operate the aircraft only within the
limits as specified in the G1000
AFMS, listed in Table 1-2
AHRS TAS
– AHRS not receiving
airspeed.
The GSU 75 AHRS card is not
receiving airspeed from the
internal air data card
•
Replace the GSU 75.
AHRS GPS
– AHRS not receiving
backup GPS information.
The GSU 75 is not receiving
backup GPS information from GIA
63 #2.
•
Ensure that a cell phone or a device
using cell phone technology is not
turned on (even in a monitoring
state) in the cabin.
•
Check GPS status for GIA 1 and 2
on MFD
Aux
– GPS Status
page. If
one or both GPS receivers cannot
acquire a position lock, see GPS
troubleshooting section
•
Troubleshoot GIA1/2
–GSU wiring
for faults (ref. Failed Path
troubleshooting section).
•
Replace the GSU 75.
AHRS GPS
– AHRS using backup
GPS source.
The GSU 75 is using the backup
GPS data path.
MAG VAR WARN
– Large
magnetic variance. Verify all
course angles.
Magnetic variance value from
GMU 44 is not accurate.
•
If flying near large radio towers or
other sources of possible
electromagnetic interference, the
condition should correct itself as the
aircraft leaves the area.
•
If problem persists, run magnetic
interference check in Section 5.9.4
to check for magnetic interference in
the aircraft.
GMU Alerts
Failure Message
Cause
Solutions
MANIFEST
– GMU software
mismatch. Communication
halted.
The system has detected an
incorrect software version loaded
in the GMU 44.
Load the correct software version.
HDG FAULT
– AHRS
magnetometer fault has occurred
A fault has occurred in the
magnetometer; heading will be
flagged invalid.
•
Check GMU 44/GSU 75
interconnect for faults.
✓
Replace GMU 44.
✓
If problem persists, replace
GSU 75.
Summary of Contents for G1000 NXi
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