GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Introduction 3
Danger, Warning, and
Caution
Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
{Danger
Danger indicates a hazard with a
high level of risk which will result
in serious injury or death.
{Warning
Warning indicates a hazard that
could result in injury or death.
Caution
Caution indicates a hazard that
could result in property or vehicle
damage.
A circle with a slash through it is a
safety symbol which means“Do
Not,” “Do not do this,” or“Do not let
this happen.”
Symbols
The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M: Shown when the owner ’s
manual has additional instructions
or information.
*: Shown when the service
manual has additional instructions
or information.
0: Shown when there is more
information on another page —
“see page.” Vehicle Symbol Chart
Here are some additional symbols
that may be found on the vehicle
and what they mean. See the
features in this manual for
information.
u:
Air Conditioning System
G:Air Conditioning Refrigerant Oil
9:Airbag Readiness Light
!:Antilock Brake System (ABS)
$:Brake System Warning Light
9:Dispose of Used Components
Properly
P: Do Not Apply High Pressure
Water
B: Engine Coolant Temperature
_: Flame/Fire Prohibited
H:Flammable
[:Forward Collision Alert
R: Fuse Block Cover Lock
Location
+: Fuses
j:ISOFIX/LATCH System Child
Restraints
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 53
Seats and
Restraints
Head Restraints
Head Restraints . . . . . . . . . . . . . . . 54
Front Seats
Seat Adjustment . . . . . . . . . . . . . . . 55
Center Seat . . . . . . . . . . . . . . . . . . . . 56
Power Seat Adjustment . . . . . . . . 56
Lumbar Adjustment . . . . . . . . . . . . 57
Reclining Seatbacks . . . . . . . . . . . 57
Memory Seats . . . . . . . . . . . . . . . . . 59
Heated and Ventilated FrontSeats . . . . . . . . . . . . . . . . . . . . . . . . . 61
Rear Seats
Rear Seats . . . . . . . . . . . . . . . . . . . . 63
Heated Rear Seats . . . . . . . . . . . . 64
Seat Belts
Seat Belts . . . . . . . . . . . . . . . . . . . . . 65
How to Wear Seat BeltsProperly . . . . . . . . . . . . . . . . . . . . . . 66
Lap-Shoulder Belt . . . . . . . . . . . . . 68
Seat Belt Use During Pregnancy . . . . . . . . . . . . . . . . . . . . 70
Seat Belt Extender . . . . . . . . . . . . . 71
Safety System Check . . . . . . . . . . 71 Seat Belt Care . . . . . . . . . . . . . . . . . 71
Replacing Seat Belt System
Parts after a Crash . . . . . . . . . . . 72
Airbag System
Airbag System . . . . . . . . . . . . . . . . . 72
Where Are the Airbags? . . . . . . . 74
When Should an AirbagInflate? . . . . . . . . . . . . . . . . . . . . . . . 76
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . 76
How Does an Airbag Restrain? . . . . . . . . . . . . . . . . . . . . . 77
What Will You See after an Airbag Inflates? . . . . . . . . . . . . . . 77
Passenger Sensing System . . . 78
Servicing the Airbag-Equipped Vehicle . . . . . . . . . . . . . . . . . . . . . . . 83
Adding Equipment to the Airbag-Equipped Vehicle . . . . . 83
Airbag System Check . . . . . . . . . . 84
Replacing Airbag System Parts after a Crash . . . . . . . . . . . . . . . . . 84
Child Restraints
Older Children . . . . . . . . . . . . . . . . . 85
Infants and Young Children . . . . 87
Child Restraint Systems . . . . . . . 89
Where to Put the Restraint . . . . . 91
Lower Anchors and Tethers forChildren (LATCH System) . . . . 92 Replacing LATCH System
Parts After a Crash . . . . . . . . . 105
Securing Child Restraints (With the Seat Belt in the
Rear Seat) . . . . . . . . . . . . . . . . . . 105
Securing Child Restraints (In the Center Front Seat) . . . . . . 108
Securing Child Restraints (With the Seat Belt in the Front
Outboard Seat) . . . . . . . . . . . . . 109
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 63
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 024 and
Vehicle Personalization 0157.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 0157.
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 - 4/4/19
66 Seats and Restraints
When riding in a vehicle, you travel
as fast as the vehicle does. If the
vehicle stops suddenly, you keep
going until something stops you.
It could be the windshield, the
instrument panel, or the seat belts!
When you wear a seat belt, you and
the vehicle slow down together.
There is more time to stop because
you stop over a longer distance and,
when worn properly, your strongest
bones take the forces from the seat
belts. That is why wearing seat belts
makes such good sense.
Questions and Answers About
Seat Belts
Q: Will I be trapped in the vehicleafter a crash if I am wearing a
seat belt?
A: You could be—whether you are
wearing a seat belt or not. Your
chance of being conscious
during and after a crash, so you
can unbuckle and get out, is
much greater if you are belted. Q: If my vehicle has airbags, why
should I have to wear seat
belts?
A: Airbags are supplemental
systems only. They work with
seat belts —not instead of them.
Whether or not an airbag is
provided, all occupants still have
to buckle up to get the most
protection.
Also, in nearly all states and in
all Canadian provinces, the law
requires wearing seat belts.
How to Wear Seat Belts
Properly
Follow these rules for everyone's
protection.
There are additional things to know
about seat belts and children,
including smaller children and
infants. If a child will be riding in the
vehicle, see Older Children 085 or
Infants and Young Children 087.
Review and follow the rules for
children in addition to the following
rules. It is very important for all occupants
to buckle up. Statistics show that
unbelted people are hurt more often
in crashes than those who are
wearing seat belts.
There are important things to know
about wearing a seat belt properly.
.
Sit up straight and always keep
your feet on the floor in front of
you (if possible).
. Always use the correct buckle
for your seating position.
. Wear the lap part of the belt low
and snug on the hips, just
touching the thighs. In a crash,
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
Seats and Restraints 69
feature stays engaged after
letting the belt go back to
stowed position on the seat,
move the seat rearward or
recline the seat until the
shoulder belt retractor lock
releases.
Engaging the child restraint
locking feature in the front
outboard seating position may
affect the passenger sensing
system, if equipped. See
Passenger Sensing System
078.If the webbing locks in the latch
plate before it reaches the
buckle, tilt the latch plate flat to
unlock.
3. Push the latch plate into the
buckle until it clicks.
Pull up on the latch plate to
make sure it is secure. If the
belt is not long enough, see
Seat Belt Extender 071.
Position the release button on
the buckle so that the seat belt
could be quickly unbuckled if
necessary.
4. To make the lap part tight, pull up on the shoulder belt.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
70 Seats and Restraints
To unlatch the belt, push the button
on the buckle. The belt should
return to its stowed position.
Always stow the seat belt slowly.
If the seat belt webbing returns
quickly to the stowed position, the
retractor may lock and cannot be
pulled out. If this happens, pull the
seat belt straight out firmly to unlock
the webbing, and then release it.
If the webbing is still locked in the
retractor, see your dealer.
Before a door is closed, be sure the
seat belt is out of the way. If a door
is slammed against a seat belt,
damage can occur to both the seat
belt and the vehicle.
Seat Belt Pretensioners
This vehicle has seat belt
pretensioners for the front outboard
occupants. Although the seat belt
pretensioners cannot be seen, they
are part of the seat belt assembly.
They can help tighten the seat belts
during the early stages of a
moderate to severe frontal, near
frontal, or rear crash if the threshold
conditions for pretensioneractivation are met. Seat belt
pretensioners can also help tighten
the seat belts in a side crash or
rollover event.
Pretensioners work only once. If the
pretensioners activate in a crash,
the pretensioners and probably
other parts of the vehicle's seat belt
system will need to be replaced.
See
Replacing Seat Belt System
Parts after a Crash 072.
Do not sit on the outboard seat belt
while entering or exiting the vehicle
or at any time while sitting in the
seat. Sitting on the seat belt can
damage the webbing and hardware.
Rear Seat Belt Comfort Guides
Rear seat belt comfort guides may
provide added seat belt comfort for
older children who have outgrown
booster seats and for some adults.
When installed on a shoulder belt,
the comfort guide positions the
shoulder belt away from the neck
and head. Comfort guides are available
through your dealer for the rear
outboard seating positions.
Instructions are included with the
comfort guides.
Seat Belt Use During
Pregnancy
Seat belts work for everyone,
including pregnant women. Like all
occupants, they are more likely to
be seriously injured if they do not
wear seat belts.