Garmin G3X Pilot's Manual page 310

Integrated Autopilot
Selected
Navigation
Source
3) G3X: From the PFD or PFD Page, press the ALT/PTCH Softkey to access
the autopilot pitch modes and then press the AP APPR Softkey. This
simultaneously selects LOC Mode and GS (Glideslope) Mode. If the
localizer deviation is less than half-scale when the AP APPR Softkey is
pressed, the autopilot will activate LOC Mode and track the localizer,
otherwise LOC Mode is armed and the pilot is responsible for intercepting
the localizer.
If the following occurs, the autopilot reverts to Roll Hold Mode (wings rolled level):
• Approach Mode is active and the Navigation source is manually
switched
• The localizer signal is lost
If the Glideslope signal is lost , GS Mode will revert to Pitch Hold Mode and hold the
last pitch attitude.
292
CDI Source
Softkey
Approach Softkeys
Garmin G3X Pilot's Guide 190-01115-00 Rev. G