190-01115-01
G3X/G3X Touch Installation Manual - Troubleshooting
Rev. AC
Page 35-2
35.1.1 Status LED
The GAD 29, GEA 24, GPS 20A, GSA 28, GSU 25, and GTR 20/200 units have an LED on their outer
cases that indicates the LRUs current status. The status indications are:
35.2 CAN Network Troubleshooting
If communication problems between LRUs are suspected, the CAN bus wiring and arrangement of devices
on the network should be examined. See
for information.
35.3 GDU 37X/4XX
35.3.1 SD Card Slot
A stuck or sticking SD card issue can sometimes be caused by the card thickness variability (especially if
there is more than one label on the card). This is usually caused by the card sticking in the overlay
opening, not by the card sticking to the socket inside the unit. Try another card (without a label if possible)
to confirm the problem before returning. If the second card sticks, the SD socket board inside the unit may
be misaligned with the overlay and the GDU will require repair. If the thickness of the card was the cause,
see if more than one label was on the card. If the labels weren’t the cause, determine what brand of SD
card was being used (Garmin recommends using SanDisk® brand cards).
35.3.2 Unit Communication Error Messages (Two or Three GDU Systems)
Error messages occur if there is a mismatch in GDU software versions. If this occurs, the GDU’s will not
communicate with each other, and a software mismatch message will be reported on the INFO page (press
the MSG softkey). Ensure both displays are running the same software version to clear the issue. Unit
communication error related messages are as follows:
•
GDU Software Version Mismatch - Indicates that two or more GDU displays are using incompati-
ble software versions. All GDUs in the aircraft must be updated to use the same software version.
•
Network Fault - Duplicate GDU Detected - Indicates that more than one GDU is configured to be
the same unit type (e.g. two displays are configured as PFD1). See section
for
information on GDU mode pin connections.
•
Network Address Changed - Indicates that the state of a GDU's mode pins was detected. Check
for loose connections and see
for information on GDU mode pin connections.
•
Navigation/Terrain/Obstacle Database Missing - Indicates that a required database is missing on
the specified GDU display. A database update is required.
•
Navigation/Terrain/Obstacle Database Mismatch - Indicates that two or more GDU displays have
different versions of the specified database. Update the databases in all GDU displays to the same
cycle number.
Table 35-1 Status LED Indications
LED Indication
Description
No Light
No Power
Steady Green
On, but not communicating via CAN Bus
Flashing Green
On and communicating via CAN Bus
Red
Hardware Fault
Alternating Red/Green
CAN bus network error two similar devices are
configured with the same unit ID
