Gdu 4X0 - Garmin G3X Touch Maintenance Manual

CAN INFO
DESCRIPTION
Network Error Passive
Network Pass Off
9. Power up only the PFD display and one CAN device at a time and verify the connection quality for
each device. Sometimes a device will only communicate with PFD when it is the only powered
device on the CAN bus, if one or more of the above issues is present. Evaluating each CAN device
in turn can help narrow down a problem.

5.3 GDU 4X0

5.3.1 Display Legibility
Degradation of the GDU 4X0 LCD or backlight may reduce legibility. Backlight brightness may also be
adversely affected by issues with an external lighting bus or the photocells in the GDU bezel. If display
elements are not easily legible under all lighting conditions encountered in the cockpit including direct
sunlight, verify that the backlight can be adjusted to an acceptable brightness level via the manual dimming
control in the PFD menu. If manual dimming adjustment results in acceptable legibility, troubleshoot the
external lighting bus input for incorrect input voltage levels. Verify photocell lenses are clean and
unobstructed. Backlight dimming configuration for lighting bus or photocell should be verified in
Configuration Mode and may be adjusted as needed. Reference the G3X Touch EFIS Part 23 AML STC
Installation Manual (190-02472-01) for further detail.
If the above steps do not result in acceptable display legibility the GDU may need to be replaced. Contact
Garmin Product Support for more information.
5.3.2 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 with a maximum capacity of 8 GB).
Replace any corrupted SD card that might be causing an issue.
5.3.3 Data Logging
Data logging on the G3X Touch GDU may be used to help troubleshoot issues. Operational data is gathered
from the G3X Touch during flight or on ground and is stored in *.csv log files on the SD card (if installed and
enabled).
5.3.4 Unit Communication Error Messages (Dual GDU Installations)
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 "Messages" page.
Use the touch panel to select the yellow "Messages" field
Messages, to view the error messages. Ensure both displays are running the same software version to clear
the issue. Unit communication error related messages and recommended actions are shown on Table 5-4.
Maintenance Manual
G3X Touch EFIS Part 23 AML STC
VALUE POSSIBLE CAUSE
≥ 2 CAN bus wiring problem
≥ 2 CAN bus wiring problem
Page 35
ACTION
Troubleshoot wiring and connection
issues that might create CAN errors
Troubleshoot wiring and connection
issues that might create CAN errors
or select Main Menu > Tools >
190-02472-02
Revision 2