Garmin G3X Touch Pilot's Manual page 331

The following AFCS controls are located separately from the GDU and GMC
305/307/507 AFCS Control Unit:
CWS/AP DISC Button
(Autopilot Disconnect)
TO/GA Button
(Takeoff/Go Around)
MET Switch
(Manual Electric Trim)
ENGAGING THE AUTOPILOT
An initial press of the AP Key on the GMC control unit will activate the Flight Director
and engage the autopilot in the default PIT and ROL modes.
190-01754-00 Rev. L
Press and release the AP DISC/CWS Button to disengage
the autopilot. Pressing and releasing the button again will
acknowledge an autopilot disconnect alert and mute the
associated aural tone.
Pressing and holding the AP DISC/CWS Button will also
interrupt Manual Electric Trim.
Selects flight director Takeoff (on ground) or Go Around (in
air) Mode
When properly configured with a GTN, if an approach
procedure is loaded, this switch also activates the missed
approach when the selected navigation source is GPS
or when the navigation source is VOR/LOC and a valid
frequency has been tuned.
Used to command manual electric trim for any properly
configured servo (pitch, roll, or yaw).
Garmin G3X Touch Pilot's Guide
AFCS
311