GMC Yukon 2021 Owner's Manual page 21

20 Keys, Doors, and Windows
If equipped, the power liftgate switch is on
the overhead console. The vehicle must be
in P (Park).
The modes are:
MAX : Opens to maximum height.
3/4 : Opens to a reduced height that can be
set from 3/4 to fully open. Use to prevent
the liftgate from opening into overhead
obstructions such as a garage door or
roof-mounted cargo. The liftgate can be
opened manually all the way.
OFF : Opens manually only.
To power open or close the liftgate, select
MAX or 3/4 mode and then:
Press twice quickly on the remote
key until the liftgate moves.
Press on the overhead console. The
driver door must be unlocked or locked
without the security armed.
Press the touch pad on the underside of
the liftgate handle after unlocking all
doors. A locked vehicle can be opened if
the remote key is within 1 m (3 ft) of the
touch pad.
Press on the bottom edge of the
liftgate next to the latch to close.
Press any liftgate button, the touch pad,
or on the remote key while the liftgate
is moving to stop it. Pressing any liftgate
button or pressing twice quickly on the
remote key restarts the operation in the
reverse direction. Pressing the touch pad on
the liftgate handle will restart the motion,
but only in the opening direction.
Caution
Manually forcing the liftgate to open or
close during a power cycle can damage
the vehicle. Allow the power cycle to
complete.
When stopping the gate at low heights it
may partially reopen.
The power liftgate may be temporarily
disabled in extremely low temperatures,
or after repeated power cycling over a short
period of time. If this occurs, the liftgate can
still be operated manually. Select OFF on the
liftgate switch.
If the vehicle is shifted out of P (Park) while
the power function is in progress, the
liftgate will continue to completion. If the
vehicle is accelerated before the liftgate has
completed moving, the liftgate may stop or
reverse direction. Check for Driver
Information Center (DIC) messages and make
sure the liftgate is closed and latched before
driving.
Falling Liftgate Detection
If the power liftgate automatically closes
after a power opening cycle, it indicates that
the system is reacting to excess weight on
the liftgate or a possible support strut
failure. Remove any excess weight.
A repetitive chime will sound while the
falling liftgate detection feature is operating.
If the liftgate continues to automatically
close after opening, see your dealer for
service before using the power liftgate.