Garmin G1000 NXi Supplemental Maintenance Manual page 92

GSU Alerts
Failure Message
MANIFEST – GRS software
mismatch. Communication
halted.
AHRS SERVICE – AHRS
magnetic-field model needs
update.
GEO LIMITS – AHRS too far
north/south, no magnetic
compass.
AHRS TAS – AHRS not receiving
airspeed.
AHRS GPS – AHRS not receiving
backup GPS information.
AHRS GPS – AHRS using backup
GPS source.
MAG VAR WARN – Large
magnetic variance. Verify all
course angles.
GMU Alerts
Failure Message
MANIFEST – GMU software
mismatch. Communication
halted.
HDG FAULT – AHRS
magnetometer fault has occurred
G1000 Supplemental Maintenance Manual
Textron Nav III Series
190-02128-04
Cause
The system has detected an
incorrect software version loaded
in the specified GRS unit.
The AHRS magnetic field model
should be updated for the
specified unit. Appears on ground
only.
No magnetic compass information
available due to being too far
north or south.
The GSU 75 AHRS card is not
receiving airspeed from the
internal air data card
The GSU 75 is not receiving
backup GPS information from GIA
63 #2.
The GSU 75 is using the backup
GPS data path.
Magnetic variance value from
GMU 44 is not accurate.
Cause
The system has detected an
incorrect software version loaded
in the GMU 44.
A fault has occurred in the
magnetometer; heading will be
flagged invalid.
Solutions
•
Load correct software version.
•
Load updated AHRS magnetic field
file. See Section 4.5.
•
Operate the aircraft only within the
limits as specified in the G1000
AFMS, listed in Table 1-2
•
Replace the GSU 75.
•
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.
•
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.
Solutions
Load the correct software version.
•
Check GMU 44/GSU 75
interconnect for faults.
✓
Replace GMU 44.
✓
If problem persists, replace
GSU 75.
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