Garmin G3X Touch Pilot's Manual page 367

When Glidepath (GP) Mode is armed for a GPS approach with vertical guidance, GPS
Mode is automatically armed.
Selecting a GPS approach with vertical guidance:
1) EXTERNAL NAVIGATOR: Ensure a GPS approach with vertical guidance
(LPV, LNAV/VNAV, LNAV+V) is loaded into the active flight plan.
2) EXTERNAL NAVIGATOR: Ensure the 'GPS' indication is showing in the
lower-left corner
3) G3X Touch: Ensure that GPS1 is the selected navigation source on the PFD.
4) EXTERNAL NAVIGATOR: Select and activate the GPS approach using the
PROC Key.
5) G3X Touch: From the PFD touch the autopilot then touch APPR.
Or:
APR Key on the GMC control unit.
Press the
LOCALIZER WITH GLIDESLOPE
LOC Mode (lateral) and GS Mode (vertical) are both armed by touching APPR
from the G3X Touch PFD or by pressing the APR Key on the GMC control unit. LOC/
ILS approach captures are inhibited if the difference between aircraft heading and
localizer course exceeds 105˚.
NOTE: To cancel Glideslope (GS) Mode without canceling LOC Mode, touch
NAV once. Pressing it a second time cancels LOC Mode.
Selecting LOC Mode with GS Mode:
1) EXTERNAL NAVIGATOR: Tune and activate the desired LOC frequency.
2) G3X Touch: Ensure that LOC1 is the selected navigation source. The HSI
should automatically slew the needle to the correct course.
3) G3X Touch: From the PFD touch the autopilot then touch APPR.
Or:
190-01754-00 Rev. L
. If not, press the CDI Key.
Garmin G3X Touch Pilot's Guide
AFCS
347