Transponder Check; Gps Receiver Check; Figure 8-1 - Transponder Setup Page (Normal Mode) - Garmin G3X Touch Maintenance Manual

8.2 Transponder Check

The GNX 375, all GTX 335(R)/345 (R) transponders, and GTX 33/33ES/330/330ES transponders with
software version 8.00 or later are compliant with RTCA/DO-181D, which specifies that the selection of
transponder ALT and GND modes may not be controlled by the pilot. To allow the transponder to be
operated in ALT mode while on the ground, for the purposes of performing periodic testing in accordance
with the requirements of 14 CFR Part 91.413, a special transponder ground maintenance test mode is
provided.
To access ground maintenance mode in a G3X Touch system:
1. Access the Transponder page, press the Menu key twice to access the main menu.
2. On the Main menu, select Setup to access setup page.
3. On the Setup page, select XPDR to access the transponder page.
4. On the transponder page, select "Enabled" under Ground Maintenance Test to force the
transponder into ALT mode.
Figure 8-1 – Transponder Setup Page (Normal Mode)
Transponder ground maintenance mode will be cancelled following a power cycle, or if the aircraft is
determined to be airborne.

8.3 GPS Receiver Check

8.3.1 GPS Receiver Signal Acquisition Test
The following steps constitute a simple test of the GPS receiver's ability to acquire a GPS signal from
satellites. This test needs to be performed outside, away from obstructions such as buildings, unless a
known working GPS signal repeater has been installed in the hangar for this type of testing.
1. Power on unit in normal mode and select the Info Page.
2. Verify that the GPS receiver is functional and able to calculate its present position
Maintenance Manual
G3X Touch EFIS Part 23 AML STC
Page 92
190-02472-02
Revision 2