190-01717-B1
G500/G600 TXi Part 23 AML STC Maintenance Manual
Rev. 1
Page 4-26
Figure 4-17 AHRS/ADC Alert Message Troubleshooting
AHRS/ADC Fault
Messages
If fault still exists,
contact Garmin.
The AHRS has
detected an in
tarmac anomaly at
the given location
The AHRS has
detected a local earth
anomaly at the given
location
If this error shows
up repeatedly
conduct the
magnetic
interference check
in Section 6.6.4 of
the G500/G600
Txi Part 23 AML
STC Installation
Manual (PN: 190-
01717-B3)
AHRS 1/2 reports
an in-tarmac
magnetic
anomaly
AHRS 1/2 reports
a local earth
magnetic
anomaly
Cause
Cause
Corrective
Action
Corrective
Action
Service
required
ADC 1/2 reports
configuration
error
ADC reports config
error
OR
RVSM is not enabled
in the system but the
ADC is expecting
RVSM
If RVSM is
expected, ensure
RVSM feature is
enabled in Feature
Enablement page.
Cause
Corrective
Action
ADC 1/2 reports
SSEC unavailable or
failed
AHRS 1/2 is not
receiving true
airspeed
Wrong RVSM
aircraft configuration
OR
ADC 2 selected on
PFD 1
Verify ADC 1/2
configuration and
wiring.
ADC loss of
communication
OR
No GTP 59 signal
Cause
Cause
Corrective
Action
Corrective
Action
ADC 1/2 airspeed
error correction is
unavailable
The alert flag has
been set by the
ADC
ADC 1/2 error
correction
inoperative
Cause
Corrective
Action
The designated
AHRS Magnetic
Model is out of
date
AHRS 1/2
magnetic model
database needs
update
Cause
Corrective
Action
Communication lost
with GMU 44
OR
GMU 44 installation
incorrect
Inspect GMU 44
wiring and
connections
AHRS 1/2 not
receiving valid
magnetometer
data
Cause
Corrective
Action
Perform AHRS
magnetic model
maintenance in
accordance with
Table 3-1
Ensure GMU 44
installation is
within ±3° of level
and less than 6°
difference from the
AHRS unit in
accordance with
G500/G600 Txi
AML STC
installation manual
If other ADC or
AHRS faults are
present correct
those faults first.
Verify ADC power
Inspect GTP 59,
connections, and
wiring.
Inspect ADC/
AHRS wiring and
connections
Replace ADC
config module
Verify ADC 1/2
configuration and
wiring.
Maintenance
Log Message
Maintenance
Log Message
If this error shows
up repeatedly
conduct the
magnetic
interference check
in Section 6.6.4 of
the G500/G600
Txi Part 23 AML
STC Installation
Manual (PN: 190-
01717-B3)