GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
42 Keys, Doors, and Windows
Turn Signal Indicator
If equipped, the mirror has turn
signal indicator lights, which flash in
the direction of the turn or lane
change.
Task Lighting
If equipped, task lighting projects
light from the outside mirrors to the
sides of the vehicle. SeeTask
Lighting 0171.
Puddle Lamps
If equipped, puddle lamps project
light from the bottom of the mirror to
the area of ground below the driver
and passenger doors. See Entry
Lighting 0173 and
Exit Lighting 0173.
Memory Mirrors
The vehicle may have memory
mirrors. See Memory Seats 058.
Lane Change Alert (LCA)
The vehicle may have LCA. See
Lane Change Alert (LCA) 0274.Folding Mirrors
Manual Folding Mirrors
If equipped, push the mirror toward
the vehicle to fold. Push the mirror
outward to return to its original
position.
Manually fold the mirrors inward to
prevent damage when going
through an automatic car wash.
Power Folding Mirrors
If equipped with power folding
mirrors:
1. Press
gto fold the mirrors in
to the folded position.
2. Press
gagain to fold the
mirrors out to the driving
position.
Resetting the Power Folding
Mirrors
Reset the power folding mirrors if:
. The mirrors are accidentally
obstructed while folding.
. The mirrors are accidentally
manually folded/unfolded.
. The mirrors will not stay in the
unfolded position.
. The mirrors vibrate at normal
driving speeds.
Manually fold both mirrors if they
are out of sync. Fold and unfold the
mirrors three times using the mirror
controls to reset them to their
normal position. A popping noise
may be heard. This sound is normal
after a manual folding operation.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
54 Seats and Restraints
The head restraint can be folded
forward to allow for better visibility
when the rear seat is unoccupied.
To fold the head restraint, press the
button on the side of the head
restraint.
When an occupant is in the seat,
always return the head restraint to
the upright position until it locks into
place. Push and pull on the head
restraint to make sure that it is
locked.
If you are installing a child restraint
in the rear seat, seeLower Anchors
and Tethers for Children (LATCH
System) 091. Center Headrest
The vehicle’s rear seat may be
equipped with a headrest in the
center seating position that cannot
be adjusted.
If you are installing a child restraint
in the rear seat, see
Lower Anchors
and Tethers for Children (LATCH
System) 091.
Front Seats
Seat Adjustment
{Warning
You can lose control of the
vehicle if you try to adjust a driver
seat while the vehicle is moving.
Adjust the driver seat only when
the vehicle is not moving.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Seats and Restraints 55
To adjust a manual seat:1. Pull the handle at the front of the seat.
2. Slide the seat to the desired position and release the
handle.
3. Try to move the seat back and forth to be sure it is locked in
place.
To adjust the seatback, see
Reclining Seatbacks 056.
To adjust the lumbar support,
if equipped, see Lumbar Adjustment
0 56.
Center Seat
If equipped, the center front
seatback doubles as an armrest and
cupholder/storage area for the driver
and passenger when the center
front seat is not used.
Pull the strap on the side of the
center seatback to fold the center
seatback. Do not use the center
seatback as a seating position when
the seatback is folded down.
To raise the seatback, push the
seatback rearward until it locks in
the upright position. Push and pull
on the seatback to make sure it is
locked.
Power Seat Adjustment
To adjust a power seat, if equipped:
.
Move the seat forward or
rearward by sliding the control
forward or rearward.
. Raise or lower the front part of
the seat cushion by moving the
front of the control up or down.
. Raise or lower the seat by
moving the rear of the control up
or down.
To adjust the seatback, see
Reclining Seatbacks 056.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Seats and Restraints 57
Manual Reclining Seatbacks
{Warning
If either seatback is not locked, it
could move forward in a sudden
stop or crash. That could cause
injury to the person sitting there.
Always push and pull on the
seatbacks to be sure they are
locked.
To adjust a manual seatback:1. Lift the lever.
The seatback will automatically
fold forward.
2. To recline, move the seatback rearward to the desired
position, then release the lever
to lock the seatback in place.
3. Push and pull on the seatback to make sure it is locked.
To return the seatback to the upright
position: 1. Lift the lever fully without applying pressure to the
seatback, and the seatback will
return to the upright position.
2. Push and pull on the seatback to make sure it is locked.Power Reclining Seatbacks
To recline a power seatback,
if equipped:
.Tilt the top of the control
rearward to recline.
. Tilt the top of the control forward
to raise.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
62 Seats and Restraints
The heated and ventilated seats
and heated steering wheel may
cancel when the vehicle is started.
These features can be manually
selected after the ignition is
turned on.
The temperature performance of an
unoccupied seat may be reduced.
This is normal.
The heated or ventilated seats will
not turn on during a remote start
unless they are enabled in vehicle
personalization. SeeRemote
Vehicle Start 025 and
Vehicle Personalization 0156.Rear Seats
Rear Seat Reminder
If equipped, the message REAR
SEAT REMINDER LOOK IN REAR
SEAT displays under certain
conditions indicating there may be
an item or passenger in the rear
seat. Check before exiting the
vehicle.
This feature will activate when a
second row door is opened while
the vehicle is on or up to 10 minutes
before the vehicle is turned on.
There will be an alert when the
vehicle is turned off. The alert does
not directly detect objects in the rear
seat; instead, under certain
conditions, it detects when a rear
door is opened and closed,
indicating that there may be
something in the rear seat.
The feature is active only once each
time the vehicle is turned on and off,
and will require reactivation by
opening and closing the second row
doors. There may be an alert even
when there is nothing in the rear
seat; for example, if a child entered the vehicle through the rear door
and left the vehicle without the
vehicle being shut off.
The feature can be turned on or off.
See
Vehicle Personalization 0156.
Folding the Rear Seat Cushion
Either side of the rear seat cushion
can be folded up for added cargo
space.
Caution
Folding a rear seat with the seat
belts still fastened may cause
damage to the seat or the seat
belts. Always unbuckle the seat
belts and return them to their
normal stowed position before
folding a rear seat.
Make sure that nothing is on the
seat cushion.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Seats and Restraints 63
To fold the seat, slowly pull the seat
cushion up.
To return the seat to the normal
seating position, slowly pull the seat
cushion down.
{Warning
A seat belt that is improperly
routed, not properly attached,
or twisted will not provide the
protection needed in a crash. The
person wearing the belt could be
seriously injured. After raising the
rear seatback, always check to be(Continued)
Warning (Continued)
sure that the seat belts are
properly routed and attached, and
are not twisted.
Heated Rear Seats
{Warning
If you cannot feel temperature
change or pain to the skin, the
seat heater may cause burns.
See the Warning under Heated
and Ventilated Front Seats 060.If available, the buttons are on the
rear of the center console. To
operate, the engine must be
running.
Press
MorLto heat the left or
right outboard seat cushion. An
indicator on the climate control
display appears when this feature
is on.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Seats and Restraints 67
Always use the correct buckle for
your seating position.
Never route the lap or shoulder belt
over an armrest.
{Warning
The seat belt can be pinched if it
is routed under plastic trim on the
seat, such as trim around the rear
seatback folding handle or side
airbag. In a crash, pinched seat
belts might not be able to provide
adequate protection. Never allow
seat belts to be routed under
plastic trim pieces.
Lap-Shoulder Belt
All seating positions in the vehicle
have a lap-shoulder belt.
The following instructions explain
how to wear a lap-shoulder belt
properly.1. Adjust the seat, if the seat is adjustable, so you can sit up
straight. To see how, see
“Seats” in the Index.
2. Pick up the latch plate and pull
the belt across you. Do not let
it get twisted.
The lap-shoulder belt may lock
if you pull the belt across you
very quickly. If this happens, let
the belt go back slightly to
unlock it. Then pull the belt
across you more slowly.
If the shoulder portion of a
passenger belt is pulled out all
the way, the child restraint
locking feature may be
engaged. See Child Restraint
Systems 088. If this occurs, let
the belt go back all the way
and start again. If the locking
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
98 Seats and Restraints
Warning (Continued)
The shoulder belt locks when it is
pulled all the way out of the
retractor. It unlocks when the
shoulder belt is allowed to go all
the way back into the retractor,
but it cannot do this if it is
wrapped around a child’s neck.
If the shoulder belt is locked and
tightened around a child’s neck,
the only way to loosen the belt is
to cut it.
Buckle any unused seat belts
behind the child restraint so
children cannot reach them. Pull
the shoulder belt all the way out
of the retractor to set the lock,
and tighten the belt behind the
child restraint after the child
restraint has been installed.
Caution
Do not let the LATCH
attachments rub against the
vehicle’s seat belts. This may
damage these parts. If necessary,
move buckled seat belts to avoid
rubbing the LATCH attachments.
Do not fold the rear seat cushion
when the seat is occupied. Do not
fold the empty rear seat with a
seat belt buckled. This could
damage the seat belt or the seat.
Unbuckle and return the seat belt
to its stowed position, before
folding the seat.
If you need to secure more than one
child restraint in the rear seat, see
Where to Put the Restraint 090.
Regular Cab Models 1. For models without a rear seat, forward-facing child restraints
should only be installed in the
right front seating position with belts and a top tether. See
Securing Child Restraints (In
the Center Front Seat)
0107 or
Securing Child Restraints (With
the Seat Belt in the Rear Seat)
0 104 or
Securing Child Restraints (With
the Seat Belt in the Front
Outboard Seat) 0108.
If the child restraint
manufacturer recommends that
the top tether be attached,
attach and tighten the top
tether to the top tether anchor,
if your vehicle has one. Refer
to the child restraint
instructions and the following
steps:
1.1. Find the top tether anchor.
1.2. Route, attach, and tighten the top tether according
to your child restraint
instructions and the
following instructions: