weight GMC SIERRA 2021 Owner's Manual

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
30 Keys, Doors, and Windows
When applying any load to the tailgate,
distribute the weight evenly across the
width of the tailgate. This applies to all
tailgate types.
.Use a load-distributing member (1).
.Secure the ramp to the bumper (2).
Power Assist Steps
{Warning
To avoid personal injury or property
damage, before entering or exiting the
vehicle, be sure the power assist step is
fully extended. Do not step on the power
assist step while it is moving. Never place
hands or other body parts between the
extended power assist step and the
vehicle.
If equipped, the power assist steps, when
enabled, will extend when the door is
opened. They will retract three seconds after
the door is closed or immediately if the
vehicle starts moving.
Keep hands, children, pets, objects, and
clothing clear of the power assist steps
when in motion. The steps will reverse direction if there is an
obstruction. If possible, carefully remove the
obstruction, then open and close the door
on the same side to complete the motion.
If the obstruction is not cleared, the assist
steps remain extended.
Slight movement of the steps while
extended is normal.
Kick Switch
1. Place the vehicle in P (Park) and unlock
the doors. 2. Kick the switch to extend the power
assist step to the tire. A Driver
Information Center (DIC) message
displays.
3. Kick the switch again to return to normal operation.
Center Stack Switch
The power assist steps can be extended to
the tire by pressing
j. When extending
the steps with
j, the kick switch is
disabled. The vehicle must be in P (Park) or
N (Neutral).

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
66 Seats and Restraints
.The vehicle has a crash sensing and
diagnostic module which records
information after a crash. SeeVehicle
Data Recording and Privacy 0437 and
Event Data Recorders 0438.
.Let only qualified technicians work on the
airbag systems. Improper service can
mean that an airbag system will not work
properly. See your dealer for service.
Passenger Sensing System
The vehicle has a passenger sensing system
for the front outboard passenger position.
The passenger airbag status indicator will
light on the overhead console when the
vehicle is started.
United States
Canada
The words ON and OFF, or the symbols for
on and off, will be visible during the system
check. When the system check is complete,
either the word ON or OFF, or the symbol
for on or off, will be visible. See Passenger
Airbag Status Indicator 0114.
The passenger sensing system turns off the
front outboard passenger frontal airbag
under certain conditions. No other airbag is
affected by the passenger sensing system.
The passenger sensing system works with
sensors that are part of the front outboard
passenger seat and seat belt. The sensors
are designed to detect the presence of a
properly seated occupant and determine if
the front outboard passenger frontal airbag
should be allowed to inflate or not.
According to accident statistics, children are
safer when properly secured in a rear seat
in the correct child restraint for their weight
and size. Whenever possible, children aged 12 and
under should be secured in a rear seating
position.
Never put a rear-facing child seat in the
front. This is because the risk to the
rear-facing child is so great, if the airbag
inflates.
{Warning
A child in a rear-facing child restraint can
be seriously injured or killed if the
passenger frontal airbag inflates. This is
because the back of the rear-facing child
restraint would be very close to the
inflating airbag. A child in a
forward-facing child restraint can be
seriously injured or killed if the passenger
frontal airbag inflates and the passenger
seat is in a forward position.
Even if the passenger sensing system has
turned off the passenger frontal airbag,
no system is fail-safe. No one can
guarantee that an airbag will not deploy
under some unusual circumstance, even
though the airbag is turned off.
(Continued)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 67
Warning (Continued)
Never put a rear-facing child restraint in
the front seat, even if the airbag is off.
If securing a forward-facing child restraint
in the front outboard passenger seat,
always move the seat as far back as it
will go. It is better to secure child
restraints in the rear seat. Consider using
another vehicle to transport the child
when a rear seat is not available.
If the vehicle does not have a rear seat that
will accommodate a rear-facing child
restraint, a rear-facing child restraint should
not be installed in the vehicle, even if the
airbag is off.
The passenger sensing system is designed to
turn off the front outboard passenger
frontal airbag if:
.The front outboard passenger seat is
unoccupied.
.The system determines an infant is
present in a child restraint.
.A front outboard passenger takes his/her
weight off of the seat for a period
of time.
.There is a critical problem with the airbag
system or the passenger sensing system.
When the passenger sensing system has
turned off the front outboard passenger
frontal airbag, the OFF indicator will light
and stay lit as a reminder that the airbag is
off. See Passenger Airbag Status Indicator
0 114.
The passenger sensing system is designed to
turn on the front outboard passenger frontal
airbag anytime the system senses that a
person of adult size is sitting properly in the
front outboard passenger seat.
When the passenger sensing system has
allowed the airbag to be enabled, the ON
indicator will light and stay lit as a reminder
that the airbag is active.
For some children, including children in child
restraints, and for very small adults, the
passenger sensing system may or may not
turn off the front outboard passenger
frontal airbag, depending upon the person's
seating posture and body build. Everyone in
the vehicle who has outgrown child
restraints should wear a seat belt
properly —whether or not there is an
airbag for that person.{Warning
If the airbag readiness light ever comes
on and stays on, it means that
something may be wrong with the airbag
system. To help avoid injury to yourself
or others, have the vehicle serviced right
away. See Airbag Readiness Light 0114
for more information, including important
safety information.
If the On Indicator Is Lit for a Child
Restraint
The passenger sensing system is designed to
turn off the front outboard passenger
frontal airbag if the system determines that
an infant is present in a child restraint. If a
child restraint has been installed and the ON
indicator is lit:
1. Turn the vehicle off.
2. Remove the child restraint from the vehicle.
3. Remove any additional items from the seat such as blankets, cushions, seat
covers, seat heaters, or seat massagers.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 71
Replacing Airbag System Parts
after a Crash
{Warning
A crash can damage the airbag systems
in the vehicle. A damaged airbag system
may not properly protect you and your
passenger(s) in a crash, resulting in
serious injury or even death. To help
make sure the airbag systems are
working properly after a crash, have
them inspected and any necessary
replacements made as soon as possible.
If an airbag inflates, you will need to
replace airbag system parts. See your dealer
for service.
If the airbag readiness light stays on after
the vehicle is started or comes on when you
are driving, the airbag system may not work
properly. Have the vehicle serviced right
away. See Airbag Readiness Light 0114.
Child Restraints
Older Children
Older children who have outgrown booster
seats should wear the vehicle’s seat belts.
The manufacturer instructions that come
with the booster seat state the weight and
height limitations for that booster. Use a
booster seat with a lap-shoulder belt until
the child passes the fit test below:
.Sit all the way back on the seat. Do the
knees bend at the seat edge? If yes,
continue. If no, return to the booster seat.
.Buckle the lap-shoulder belt. Does the
shoulder belt rest on the shoulder? If yes,
continue. If no, try using the rear seat belt comfort guide, if available. See
“Rear
Seat Belt Comfort Guides” under
Lap-Shoulder Belt 057. If a comfort guide
is not available, or if the shoulder belt
still does not rest on the shoulder, then
return to the booster seat.
.Does the lap belt fit low and snug on the
hips, touching the thighs? If yes, continue.
If no, return to the booster seat.
.Can proper seat belt fit be maintained for
the length of the trip? If yes, continue.
If no, return to the booster seat.
Q: What is the proper way to wear seat belts?
A: An older child should wear a lap-shoulder
belt and get the additional restraint a
shoulder belt can provide. The shoulder
belt should not cross the face or neck.
The lap belt should fit snugly below the
hips, just touching the top of the thighs.
This applies belt force to the child's
pelvic bones in a crash. It should never
be worn over the abdomen, which could
cause severe or even fatal internal
injuries in a crash.
Also see “Rear Seat Belt Comfort Guides”
under Lap-Shoulder Belt 057.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
74 Seats and Restraints
There are three basic types of child
restraints:
.Forward-facing child restraints
.Rear-facing child restraints
.Belt-positioning booster seats
The proper child restraint for your child
depends on their size, weight, and age, and
also on whether the child restraint is
compatible with the vehicle in which it will
be used.
For each type of child restraint, there are
many different models available. When
purchasing a child restraint, be sure it is
designed to be used in a motor vehicle. If it
is, the child restraint will have a label saying
that it meets federal motor vehicle safety
standards.
The instruction manual that is provided with
the child restraint states the weight and
height limitations for that particular child
restraint. In addition, there are many kinds
of child restraints available for children with
special needs.
{Warning
To reduce the risk of neck and head
injury in a crash, infants and toddlers
should be secured in a rear-facing child
restraint until age two, or until they
reach the maximum height and weight
limits of their child restraint.
{Warning
A young child's hip bones are still so
small that the vehicle seat belt may not
remain low on the hip bones, as it
should. Instead, it may settle up around
the child's abdomen. In a crash, the belt
would apply force on a body area that is
unprotected by any bony structure. This
alone could cause serious or fatal injuries.
To reduce the risk of serious or fatal
injuries during a crash, young children
should always be secured in an
appropriate child restraint.
Child Restraint Systems
Rear-Facing Infant Restraint
A rear-facing child restraint provides
restraint with the seating surface against
the back of the infant.
The harness system holds the infant in place
and, in a crash, acts to keep the infant
positioned in the restraint.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
78 Seats and Restraints
Make sure to follow the instructions that
came with the child restraint, and also the
instructions in this manual.
When installing a child restraint with a top
tether, you must also use either the lower
anchors or the seat belts to properly secure
the child restraint. A child restraint must
never be installed using only the top tether.
For a forward-facing 5-pt harness child
restraint where the combined weight of the
child and restraint are up to 29.5 kg (65 lb),
use either the lower LATCH anchorages with
the top tether anchorage, or the seat belt
with the top tether anchorage. Where the
combined weight of the child and restraint
are greater than 29.5 kg (65 lb), use the seat
belt with the top tether anchorage only.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 79
Recommended Methods for Attaching Child Restraints
Restraint Type Combined Weight ofthe Child + Child
Restraint Use Only Approved Attachment Methods Shown with an X
LATCH
–Lower
Anchors Only Seat Belt Only LATCH
–Lower
Anchors and Top
Tether Anchor Seat Belt and Top
Tether Anchor
Rear-Facing Child
Restraint Up to 29.5 kg (65 lb)
X X
Rear-Facing Child
Restraint Greater than
29.5 kg (65 lb) X
Forward-Facing Child
Restraint Up to 29.5 kg (65 lb)
X X
Forward-Facing Child
Restraint Greater than
29.5 kg (65 lb) X
See Securing Child Restraints (With the Seat
Belt in the Center Front Seat) 092 or
Securing Child Restraints (With the Seat Belt
in the Rear Seat) 088 or
Securing Child Restraints (With the Seat Belt
in the Front Passenger Seat) 092. Child restraints built after March 2014 will
be labeled with the specific child weight up
to which the LATCH system can be used to
install the restraint.
The following explains how to attach a child
restraint with these attachments in the
vehicle. Not all vehicle seating positions have lower
anchors. In this case, the seat belt must be
used (with top tether where available) to
secure the child restraint. See
Securing Child
Restraints (With the Seat Belt in the Center
Front Seat) 092 or
Securing Child Restraints (With the Seat Belt
in the Rear Seat) 088 or
Securing Child Restraints (With the Seat Belt
in the Front Passenger Seat) 092.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 85
1.1. Find the lower anchors for thedesired seating position.
1.2. Put the child restraint on the seat.
1.3. Attach and tighten the lower attachments on the child restraint
to the lower anchors.
2. For forward-facing child restraints, attach and tighten the top tether to the top
tether anchor, if your vehicle has one.
Follow the child restraint instructions and
the vehicle LATCH anchor weight limits
described at the beginning of this
section, and the following steps:
Rear Driver Side Position
Rear Driver Side Position
2.1. For a top tether in the rear driver side position:
2.1.1. Remove the driver side head restraint and center
headrest. See “Head
Restraint or Headrest
Removal and Reinstallation”
later in this section.2.1.2. For first time use, remove and discard the rubber band
from the top tether loop (2).
2.1.3. Route the top tether (3) through the loop (2).
2.1.4. Attach the top tether (3) to the driver side of the center
top tether metal anchor (1).
2.1.5. Make sure the child restraint top tether hook is
completely closed and
secured to the top tether
anchor.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
90 Seats and Restraints
6. To tighten the belt, push down on thechild restraint, pull the shoulder portion
of the belt to tighten the lap portion of
the belt, and feed the shoulder belt back
into the retractor. When installing a
forward-facing child restraint, it may be
helpful to use your knee to push down
on the child restraint as you tighten
the belt.
Try to pull the belt out of the retractor
to make sure the retractor is locked.
If the retractor is not locked, repeat
Steps 5 and 6. 7. For forward-facing child restraints, attach
and tighten the top tether to the top
tether anchor (loop). Refer to the child
restraint instructions, the vehicle LATCH
anchor weight limits, and instructions
listed in Lower Anchors and Tethers for
Children (LATCH System) 077.
8. Before placing a child in the child restraint, make sure it is securely held in
place. To check, grasp the child restraint
at the seat belt path and attempt to
move it side to side and back and forth.
When the child restraint is properly
installed, there should be no more than
2.5 cm (1 in) of movement.
To remove the child restraint, unbuckle the
vehicle seat belt and let it return to the
stowed position. If the top tether is attached
to a top tether anchor, disconnect it.
Reinstall the head restraint or headrest
before the seating position is used. See
“Head Restraint or Headrest Removal and
Reinstallation” underLower Anchors and
Tethers for Children (LATCH System) 077 for
additional information on installing the
headrest properly.
Crew Cab
1. Put the child restraint on the seat.
2. Pick up the latch plate, and run the lap and shoulder portions of the vehicle seat
belt through or around the child
restraint. The child restraint instructions
will show you how.
3. Push the latch plate into the buckle untilit clicks.
Position the release button on the
buckle, away from the child restraint, so
that the seat belt could be quickly
unbuckled if necessary.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 217
{Warning
If the vehicle has the two-speed
automatic transfer case, shifting the
transfer case to N (Neutral) can cause
your vehicle to roll even if the
transmission is in P (Park). This is because
the N (Neutral) position on the transfer
case overrides the transmission. You or
someone else could be injured. If leaving
the vehicle, set the parking brake and
shift the transmission to P (Park). Shift
the transfer case to any position but
N (Neutral).
.When driving down a hill, keep the
vehicle headed straight down. Use a low
gear because the engine will work with
the brakes to slow the vehicle and help
keep the vehicle under control.
{Warning
Heavy braking when going down a hill
can cause your brakes to overheat and
fade. This could cause loss of control and
you or others could be injured or killed.(Continued)
Warning (Continued)
Apply the brakes lightly when descending
a hill and use a low gear to keep vehicle
speed under control.
If a brake fade condition is detected, a DIC
warning message is displayed. Adjust brake
pedal use and shift to a lower transmission
gear to reduce braking.
If the brakes continue to fade to a severe
condition, additional DIC messages are
displayed. The brake system warning light
will illuminate, and the vehicle speed may
be limited. See Brake System Warning Light
0 117.
If the vehicle stalls on a hill: 1. Apply the brakes to stop the vehicle, and then apply the parking brake.
2. Shift into P (Park) and then restart the engine.
.If driving uphill when the vehicle
stalls, shift to R (Reverse), release the
parking brake, and back
straight down.
.Never try to turn the vehicle around.
If the hill is steep enough to stall the
vehicle, it is steep enough to cause it
to roll over.
.If you cannot make it up the hill,
back straight down the hill.
.Never back down a hill in N (Neutral)
using only the brake. The vehicle can
roll backward quickly and you could
lose control.
.If driving downhill when the vehicle
stalls, shift to a lower gear, release
the parking brake, and drive straight
down the hill.
3. If the vehicle cannot be restarted after stalling, set the parking brake, shift into
P (Park), and turn the vehicle off.
3.1. Leave the vehicle and seek help.
3.2. Stay clear of the path the vehicle would take if it rolled downhill.
.Avoid turns that take the vehicle across
the incline of the hill. A hill that can be
driven straight up or down might be too
steep to drive across. Driving across an
incline puts more weight on the downhill
wheels, which could cause a downhill
slide or a rollover.