Figure 4-17 Ahrs Alert Message Troubleshooting - Garmin GI 275 Maintenance Manual

AHRS <1/2/3>
AHRS <1/2/3>
MISCOMPARE
MISSING
-or-
AHRS MISSING MISCOMPARE
Maintenance Maintenance
Log Message Log Message
AHRS <1/2/3> data is AHRS <1/2/3> does not
missing and cannot be match other senosrs
compared
All AHRS sensors do not
Not enough AHRS sensors
to perform a comparison
Cause
Multiple AHRS are configured, a
Multiple AHRS are
reported AHRS heading
configured in the
difference of 6 degrees or more
system and the
reported AHRS is not
detected
Multiple AHRS are configured, a
reported AHRS pitch or roll of
5 degrees or more is detected
Corrective Corrective
Action
Ensure the missing Determine if pitch,
AHRS is powered roll or heading is out
of tolerance
Ensure the missing
AHRS configuration
Heading out of
is correct
tolerance: perform
magnetic calibration
on all configured
Verify wiring is
heading sources
correct
190-02246-11
Rev. 1
AHRS Fault
Messages
AHRS <1/2/3>:
Magnetic model
-or- AHRS outdated
Maintenance
Log Message
AHRS <1/2/3>
Magnetic Model
out of date
match
Cause Cause
Magnetic model is
out of date
is detected
Corrective
Action Action
Update the IGRF
Magnetic Field
Model
Pitch or roll out of
tolerance: perform
pitch-roll offset
calibration on all
configured sources

Figure 4-17 AHRS Alert Message Troubleshooting

AHRS <1/2/3> not AHRS <1/2/3>
receiving GPS reports service
aiding required
Maintenance
Log Message
AHRS <1/2/3> not
receiving GPS
aiding
Cause Cause
Not receiving GPS Bad AHRS calibration
data from a
No data from ADC
configured GPS
source
Corrective Corrective
Action Action
Verify GPS Ensure ADC is
configurations powered on
Verify GPS antenna has a Perform AHRS
clear view of the sky and
calibration
GPS source has a valid fix
Verify connections
Verify connections
and wiring
and wiring
Service required Magnetic variance
inaccurate
Maintenance
Maintenance
Log Message
Log Message
<AHRS>
ADB and IOP
configuration does
packet magnetic
not match what the
variances differ
unit expected
Cause
Cause
AHRS LRU is not
configured correctly
Aviation database
out-of-date on
GI 275 / Navigator
Corrective
Action
Corrective
Action
Ensure aviation
database is up-to-
date on GI 275 and
configured navigator
Verify AHRS
configuration
settings
GI 275 Part 23 AML STC Maintenance Manual
Magnetic variance
unavailable
Maintenance
Log Message
ADB is unavailable
for magnetic
variance
Cause
Aviation database is missing
Navigator / GPS source
unavailable
Corrective
Action
Ensure aviation
database is loaded
and up-to-date
Verify GPS source
online
If fault persists,
contact Garmin.
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