Garmin G1000 Nxi System Maintenance Manual page 218

Failure Message
MAG VAR WARN – Large
magnetic variance. Verify all
course angles.
PIT (amber pitch flag)
ROL (amber roll flag)
GMU Alerts
Failure Message
MANIFEST – GMU1 software
mismatch. Communication
halted.
MANIFEST – GMU2 software
mismatch. Communication
halted.
HDG FAULT – AHRS1
magnetometer fault has occurred
HDG FAULT – AHRS2
magnetometer fault has occurred.
HDG (amber heading flag)
G1000 NXi System Maintenance Manual
King Air 300 Series
190-00716-N1
Cause
Magnetic variance value from
GMU 44 is not accurate.
Pitch Miscompare:
Difference in the pitch sensors is
greater than 5 degrees.
Roll Miscompare:
Difference in the roll sensors is
greater than 6 degrees.
Cause
The system has detected an
incorrect software version loaded
in the specified GMU 44.
A fault has occurred in the
specified magnetometer; heading
will be flagged invalid.
Heading Miscompare:
Difference in the heading sensors
is greater than 6 degrees.
Solutions
•
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 5.17.4
to check for magnetic interference in
the aircraft.
Perform Calibration Procedure A1: GSU
75B, GRS 77, or GRS 7800 Pitch/Roll
Offset Calibration (reference Section
7.10.1).
Perform Calibration Procedure A1: GSU
75B, GRS 77, or GRS 7800 Pitch/Roll
Offset Calibration (reference Section
7.10.1).
Solutions
Load the correct software version.
•
Check GMU 44/GSU 75B, GRS 77,
or GRS 7800 interconnect for faults.

Replace GMU 44.

If problem persists, replace
GSU 75B, GRS 77 or
GRS 7800.
Perform Calibration Procedure E:
Magnetometer Interference Test
(reference Section 5.17.4) and
Procedure B: GSU 75B, GRS 77, or
GRS 7800 and GMU 44 Magnetometer
Calibration (reference Section 7.10.3).
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