warning GMC SIERRA 2020 Owner's Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 55
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) 092. 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) 092.
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.
To adjust a manual seat:
1. Pull the handle at the front of the seat.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 57
To adjust the lumbar support, see
Lumbar Adjustment057.
Some vehicles are equipped with a
feature that activates a vibrating
pulse alert in the driver seat to help
the driver avoid crashes. See Driver
Assistance Systems 0256.
Lumbar Adjustment
Power Lumbar
To adjust the lumbar support,
if equipped: .
Press and hold the control
forward to increase or rearward
to decrease upper and lower
lumbar support at the same time.
Reclining Seatbacks
{Warning
Sitting in a reclined position when
the vehicle is in motion can be
dangerous. Even when buckled
up, the seat belts cannot do
their job.
The shoulder belt will not be
against your body. Instead, it will
be in front of you. In a crash, you
could go into it, receiving neck or
other injuries.
The lap belt could go up over
your abdomen. The belt forces
would be there, not at your pelvic
bones. This could cause serious
internal injuries.
(Continued)
Warning (Continued)
For proper protection when the
vehicle is in motion, have the
seatback upright. Then sit well
back in the seat and wear the
seat belt properly.
Do not have a seatback reclined if
the vehicle is moving.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
58 Seats and Restraints
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 - 4/4/19
Seats and Restraints 61
memory button number 1 or 2 are
automatically recalled when the
vehicle is turned on, or turned from
off to ACC/ACCESSORY. RKE
transmitters 3–8 will not provide
automatic memory recalls.
To turn Seat Entry Memory on or off,
see“Vehicle Personalization
Settings” previously in this section
and Vehicle Personalization 0157.
The shift lever must be in P (Park)
to start Seat Entry Memory. Seat
Entry Memory recall will complete if
the vehicle is shifted out of P (Park)
prior to reaching the saved memory
position.
To stop Seat Entry Memory recall
movement, turn the vehicle off or
press any of the following controls:
. Power seat
. Memory SET, 1, 2, or
B
.Power mirror, with the driver or
passenger side mirror selected
If the saved memory seat position
does not automatically recall or
recalls to the wrong positions, the
driver ’s RKE transmitter number (1 or 2) may not match the memory
button number that positions were
saved to. Try storing the position to
the other memory button or try the
other RKE transmitter.
Seat Exit Memory
Seat Exit Memory is not linked to an
RKE transmitter. The position saved
to
Bis used for all drivers. To turn
Seat Exit Memory on or off, see
"Vehicle Personalization Settings"
previously in this section and
Vehicle Personalization 0157.
If turned on, the position saved to
Bis automatically recalled when
one of the following occurs:
. The vehicle is turned off and the
driver door is opened within a
short time.
. The vehicle is turned off with the
driver door open.
To stop Seat Exit Memory
movement, press any of the
following memory controls:
. Power seat
. Memory SET, 1, 2, or
B
.
Power mirror, with the driver or
passenger side mirror selected
Obstructions
If something has blocked the driver
seat while recalling a memory
position, the recall may stop.
Remove the obstruction and try the
recall again. If the memory position
still does not recall, see your dealer.
Heated and Ventilated
Front Seats
{Warning
If temperature change or pain to
the skin cannot be felt, the seat
heater may cause burns. To
reduce the risk of burns, use care
when using the seat heater,
especially for long periods of
time. Do not place anything on
the seat that insulates against
heat, such as a blanket, cushion,
cover, or similar item. This may
cause the seat heater to (Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
62 Seats and Restraints
Warning (Continued)
overheat. An overheated seat
heater may cause a burn or may
damage the seat.
Heated and Ventilated Seat
Buttons Shown, Heated Seat
Buttons Similar
If equipped, the buttons are on the
center stack. To operate, the engine
must be running.
Press
Ior+to heat the driver or
passenger seatback only. Press
Jorzto heat the driver or
passenger seat cushion and
seatback.
Press
Cor{to ventilate the driver
or passenger seat.
The indicator light on the button
comes on when this feature is on.
Press the button once for the
highest setting. With each press of
the button, the seat will change to
the next lower setting, and then to
the off setting. The indicator lights
next to the buttons indicate three for
the highest setting and one for the
lowest. If the heated seats are on
high for an extended time, their level
may automatically be lowered.
Auto Heated Seats
When the vehicle is on, this feature
will automatically activate the
heated seats at the level required by
the vehicle’ s interior temperature.
The active high, medium, low, or off
heated seat level will be indicated
by the manual heated seat buttons
on the center stack. Use the manual
heated seat buttons on the center stack to turn auto heated seats off.
If the passenger seat is unoccupied,
the auto heated seats feature will
not activate that seat. The auto
heated seats feature can be
programmed to always be enabled
when the vehicle is on. See
Vehicle
Personalization 0157.
Remote Start Heated and
Ventilated Seats
If equipped, the heated seats will
turn on automatically during a
remote start if it is cold outside and
the ventilated seats will turn on
automatically if it is hot outside.
If equipped, the heated steering
wheel will turn on automatically
during a remote start if it is cold
outside. The heated and ventilated
seat indicators and heated steering
wheel indicator may not come on
during this operation.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
64 Seats and Restraints
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 061.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.
This feature turns on at the highest
setting. With each press of the
button, the heated seat changes to
the next lower setting, and then the
off setting. Three lights indicate the
highest setting, and one light
indicates the lowest. If the heated

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 65
seats are on high, the level may
automatically be lowered after
approximately 30 minutes.Seat Belts
This section describes how to use
seat belts properly, and some things
not to do.
{Warning
Do not let anyone ride where a
seat belt cannot be worn properly.
In a crash, if you or your
passenger(s) are not wearing
seat belts, injuries can be much
worse than if you are wearing
seat belts. You can be seriously
injured or killed by hitting things
inside the vehicle harder or by
being ejected from the vehicle. In
addition, anyone who is not
buckled up can strike other
passengers in the vehicle.
It is extremely dangerous to ride
in a cargo area, inside or outside
of a vehicle. In a collision,
passengers riding in these areas
are more likely to be seriously
injured or killed. Do not allow(Continued)
Warning (Continued)
passengers to ride in any area of
the vehicle that is not equipped
with seats and seat belts.
Always wear a seat belt, and
check that all passenger(s) are
restrained properly too.
This vehicle has indicators as a
reminder to buckle the seat belts.
See Seat Belt Reminders 0136.
Why Seat Belts Work

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 67
this applies force to the strong
pelvic bones and you would be
less likely to slide under the lap
belt. If you slid under it, the belt
would apply force on your
abdomen. This could cause
serious or even fatal injuries.
. Wear the shoulder belt over the
shoulder and across the chest.
These parts of the body are best
able to take belt restraining
forces. The shoulder belt locks if
there is a sudden stop or crash.
{Warning
You can be seriously injured,
or even killed, by not wearing
your seat belt properly.
Never allow the lap or shoulder belt
to become loose or twisted.Never wear the shoulder belt under
both arms or behind your back.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
68 Seats and Restraints
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 089. 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 - 4/4/19
72 Seats and Restraints
{Warning
Do not bleach or dye seat belt
webbing. It may severely weaken
the webbing. In a crash, they
might not be able to provide
adequate protection. Clean and
rinse seat belt webbing only with
mild soap and lukewarm water.
Allow the webbing to dry.
Replacing Seat Belt
System Parts after a
Crash
{Warning
A crash can damage the seat belt
system in the vehicle. A damaged
seat belt system may not properly
protect the person using it,
resulting in serious injury or even
death in a crash. To help make
sure the seat belt systems are
working properly after a crash,(Continued)
Warning (Continued)
have them inspected and any
necessary replacements made as
soon as possible.
After a minor crash, replacement of
seat belts may not be necessary.
But the seat belt assemblies that
were used during any crash may
have been stressed or damaged.
See your dealer to have the seat
belt assemblies inspected or
replaced.
New parts and repairs may be
necessary even if the seat belt
system was not being used at the
time of the crash.
Have the seat belt pretensioners
checked if the vehicle has been in a
crash, or if the airbag readiness light
stays on after you start the vehicle
or while you are driving. See Airbag
Readiness Light 0136.
Airbag System
The vehicle has the following
airbags:
.
A frontal airbag for the driver
. A frontal airbag for the front
outboard passenger
. A seat-mounted side impact
airbag for the driver
. A seat-mounted side impact
airbag for the front outboard
passenger
. A roof-rail airbag for the driver
and the passenger seated
directly behind the driver
. A roof-rail airbag for the front
outboard passenger and the
passenger seated directly
behind the front outboard
passenger
All vehicle airbags have the word
AIRBAG on the trim or on a label
near the deployment opening.