190-01717-B1
G500/G600 TXi Part 23 AML STC Maintenance Manual
Rev. 1
Page 4-25
Figure 4-16 PFD Alert Message Troubleshooting
PFD Fault Messages
If fault still exists,
contact Garmin.
HDG Fail
GPS 1/2 interface
failed.
GPS TIME MARK
1/2 FAIL
Improper installation of
GMU 44 and/or AHRS
OR
Excessive magnetic
interference
The PFD has not
received a pulse in
3 seconds or more
Cause
Perform Magnetic
Interference check
in Section 6.6.4
Verify GMU 44
and AHRS
mounting locations
are within ±3° of
level and no more
than 6° of each
other(see LRU
installation
instructions in
G500/G600 Txi
Part 23 AML
Installation Manual
(P/N:190-01717-
B3) for more
information)
Verify the GPS
source is on and
has a clear view of
the sky
Inspect GPS
antenna, wiring,
and connections
Verify the GPS
source is on and
has a clear view of
the sky
Corrective
Action
GPS 1/2
inoperative
Cause
A GPS source has
lost communication
OR
A GPS source is
reporting failed
Corrective
Action
Service
Soon
Cause
Corrective
Action
AHRS 1/2 not
receiving GPS
aiding
The AHRS has
reported that no
GPS data is being
received
Verify the GPS
source is on and
has a clear view of
the sky
AHRS 1/2
not receiving
GPS Aiding
Cause
Corrective
Action
GDU( ) <ALT, IAS, EIS, or
Attitude> GPU monitor
restarted the unit.
An internal data
check has failed and
restarted the GDU
GDU( ) GPU
monitor
restarted the
unit
Cause
Corrective
Action
NAV 1/2
interface/unit
failed
A NAV source has
lost communication
OR
A NAV source is
reporting failed
If reporting failed,
troubleshoot in
accordance with
NAV unit
maintenance
manual.
Verify the NAV
source is on and
not reporting failed
NAV 1/2
inoperative
Cause
Corrective
Action
Inspect GPS
antenna, wiring,
and connections
Contact Garmin
Technical Support
Verify GDU and
GPS configuration
settings
Verify GDU and
GPS configuration
settings
Inspect GPS
antenna, wiring,
and connections
Verify GDU and
GPS configuration
settings
Inspect NAV
wiring,
connections, and
configuration
settings
Maintenance
Log Message
Maintenance
Log Message
Maintenance
Log Message
Maintenance
Log Message
Maintenance
Log Message
