Garmin G1000 System Maintenance Manual page 218

Failure Message
MAG VAR WARN – Large
magnetic variance. Verify all
course angles.
PIT MISCOMP
ROL MISCOMP
5.15.3 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 MISCOMP
Page 5-70
Revision 4
Cause
Magnetic variance value from
GMU 44 is not accurate.
Difference in the pitch sensors is
greater than 5 degrees.
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.
Difference in the heading sensors
is greater than 6 degrees.
G1000 / GFC 700 System Maintenance Manual - 300/B300 Series King Air
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 5.15.4
to check for magnetic interference in
the aircraft.
Perform Calibration Procedure A1: GRS
77 or GRS 7800 Pitch/Roll Offset
Calibration (reference Section 7).
Perform Calibration Procedure A1: GRS
77 or GRS 7800 Pitch/Roll Offset
Calibration (reference Section 7).
Solutions
Load the correct software version. See
Section 3.9 for the Software Load
Procedure.
•
Check GMU 44/GRS 77 or GRS
7800 interconnect for faults.
Replace GMU 44.
If problem persists, replace
GRS 77 or GRS 7800.
Perform Calibration Procedure E:
Magnetometer Interference Test
(reference Section 5) and Procedure B:
GRS 77 or GRS 7800 and GMU 44
Magnetometer Calibration (reference
Section 7).
190-00716-01