height GMC SIERRA DENALI 2020 Owners Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Seats and Restraints 53
Head Restraints
{Warning
With head restraints that are not
installed and adjusted properly,
there is a greater chance that
occupants will suffer a neck/
spinal injury in a crash. Do not
drive until the head restraints for
all occupants are installed and
adjusted properly.
Front Seats
The vehicle's front seats have
adjustable head restraints in the
outboard seating positions.
Adjust the head restraint so that the
top of the restraint is at the same
height as the top of the occupant's
head. This position reduces the
chance of a neck injury in a crash.To raise or lower the head restraint,
press the button on the side of the
head restraint and pull up or push
the head restraint down and release
the button.
Pull and push on the head restraint
after the button is released to make
sure that it is locked in place.
The front seat outboard head
restraints are not removable.
Rear Head Restraints
The vehicle’s rear seat has head
restraints in the outboard seating
positions that cannot be adjusted.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
70 Seats and Restraints
A pregnant woman should wear a
lap-shoulder belt, and the lap
portion should be worn as low as
possible, below the rounding,
throughout the pregnancy.
The best way to protect the fetus is
to protect the mother. When a seat
belt is worn properly, it is more likely
that the fetus will not be hurt in a
crash. For pregnant women, as for
anyone, the key to making seat
belts effective is wearing them
properly.
Seat Belt Extender
If the vehicle's seat belt will fasten
around you, you should use it.
But if a seat belt is not long enough,
your dealer will order you an
extender. When you go in to order it,
take the heaviest coat you will wear,
so the extender will be long enough
for you. To help avoid personal
injury, do not let someone else use
it, and use it only for the seat it is
made to fit. The extender has been
designed for adults. Never use it for
securing child restraints. For moreinformation on the proper use and fit
of seat belt extenders see the
instruction sheet that comes with
the extender.
Safety System Check
Periodically check the seat belt
reminder, seat belts, buckles, latch
plates, retractors, shoulder belt
height adjusters (if equipped), and
seat belt anchorages to make sure
they are all in working order. Look
for any other loose or damaged seat
belt system parts that might keep a
seat belt system from performing
properly. See your dealer to have it
repaired. Torn, frayed, or twisted
seat belts may not protect you in a
crash. Torn or frayed seat belts can
rip apart under impact forces. If a
belt is torn or frayed, have it
replaced immediately. If a belt is
twisted, it may be possible to
untwist by reversing the latch plate
on the webbing. If the twist cannot
be corrected, ask your dealer to
fix it.
Make sure the seat belt reminder
light is working. See
Seat Belt
Reminders 0135.
Keep seat belts clean and dry. See
Seat Belt Care 070.Seat Belt Care
Keep belts clean and dry.
Seat belts should be properly cared
for and maintained.
Seat belt hardware should be kept
dry and free of dust or debris. As
necessary, exterior hard surfaces
and seat belt webbing may be lightly
cleaned with mild soap and water.
Ensure there is not excessive dust
or debris in the mechanism. If dust
or debris exists in the system please
see the dealer. Parts may need to
be replaced to ensure proper
functionality of the system.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
82 Seats and Restraints
Warning (Continued)
seatback may interfere with the
proper operation of the passenger
sensing system.
Servicing the
Airbag-Equipped Vehicle
Airbags affect how the vehicle
should be serviced. There are parts
of the airbag system in several
places around the vehicle. Your
dealer and the service manual have
information about servicing the
vehicle and the airbag system. To
purchase a service manual, see
Publication Ordering Information
0471.
{Warning
For up to 10 seconds after the
vehicle is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
(Continued)
Warning (Continued)
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet
metal, may keep the airbag system
from working properly.
The operation of the airbag system
can also be affected by changing,
including improperly repairing or
replacing, any parts of the following:
.Airbag system, including airbag
modules, front or side impact
sensors, sensing and diagnostic
module, or airbag wiring .
Front seats, including stitching,
seams, or zippers
. Seat belts
. Steering wheel, instrument
panel, overhead console, ceiling
trim, or pillar garnish trim
. Inner door seals, including
speakers
Your dealer and the service manual
have information about the location
of the airbag modules and sensors,
sensing and diagnostic module, and
airbag wiring along with the proper
replacement procedures.
In addition, the vehicle has a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger seat. The
passenger sensing system may not
operate properly if the original seat
trim is replaced with non-GM
covers, upholstery, or trim; or with
GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad
or device, installed under or on top

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
84 Seats and Restraints
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 Light0135.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 067.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Seats and Restraints 87
{Warning
Children who are up against,
or very close to, any airbag when
it inflates can be seriously injured
or killed. Never put a rear-facing
child restraint in the front
outboard seat. Secure a
rear-facing child restraint in a rear
seat. It is also better to secure a
forward-facing child restraint in a
rear seat. If you must secure a
forward-facing child restraint in
the front outboard seat, always
move the front passenger seat as
far back as it will go.
Child restraints are devices used to
restrain, seat, or position children in
the vehicle and are sometimes
called child seats or car seats.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Instruments and Controls 155
Clean the HUD lens with a soft cloth
sprayed with glass cleaner. Wipe
the lens gently, then dry it.
HUD Troubleshooting
Check that:
.Nothing is covering the
HUD lens.
. The HUD brightness setting is
not too dim or too bright.
. The HUD is adjusted to the
proper height.
. Polarized sunglasses are
not worn.
. The windshield and HUD lens
are clean.
If the HUD image is not correct,
contact your dealer.
The windshield is part of the HUD
system. See Windshield
Replacement 0365.
Vehicle Messages
Messages displayed on the Driver
Information Center (DIC) indicate
the status of the vehicle or some
action that may be needed to
correct a condition. Multiple
messages may appear one after
another.
The messages that do not require
immediate action can be
acknowledged and cleared by
pressing the thumbwheel. The
messages that require immediate
action cannot be cleared until that
action is performed.
All messages should be taken
seriously; clearing the message
does not correct the problem.
If a SERVICE message appears,
see your dealer.
Follow the instructions given in the
messages. The system displays
messages regarding the following
topics:
.
Service Messages
. Fluid Levels .
Vehicle Security
. Brakes
. Steering
. Ride Control Systems
. Driver Assistance Systems
. Cruise Control
. Lighting and Bulb Replacement
. Wiper/Washer Systems
. Doors and Windows
. Seat Belts
. Airbag Systems
. Engine and Transmission
. Tire Pressure
. Battery
Engine Power Messages
ENGINE POWER IS REDUCED
This message displays when the
vehicle's propulsion power is
reduced. A reduction in propulsion
power can affect the vehicle's ability
to accelerate. If this message is on,
but there is no observed reduction

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 205
well. The center of gravity height
must not extend above the top
of the pickup box flareboard.
Any load that extends beyond
the vehicle's taillamp area must
be properly marked according to
local laws and regulations.
Remember not to exceed the
Gross Axle Weight
Rating (GAWR) of the front or
rear axle.
Add-On Equipment
When carrying removable items,
a limit on how many people
carried inside the vehicle may
be necessary. Be sure to weigh
the vehicle before buying and
installing the new equipment.Caution
Overloading the vehicle may
cause damage. Repairs would not
be covered by the vehicle
warranty. Do not overload the
vehicle.
Remember not to exceed the
Gross Axle Weight
Rating (GAWR) of the front or
rear axle.
* Equipment Maximum
Weight
Ladder Rack
and Cargo 340 kg (750 lb)
Cross Toolbox
and Cargo 181 kg (400 lb)
Side Boxes
and Cargo 113 kg per
side (250 lb
per side)
* The combined weight for all
rail-mounted equipment should
not exceed 454 kg (1,000 lb).
Loading Points
1. Primary Load Points
2. Secondary Load Areas
3. GM Approved Accessory Mounting Points
Structural members (1) and (2) are
included in the pickup box design.
Additional accessories should use
these load points. Depending on the
accessory design, use a spacer
under the accessory at the load
points to remove gap. The holes for
GM approved accessories (3) are
not intended for aftermarket

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 275
Warning (Continued)
provide alerts when changing
lanes under all driving conditions.
Failure to use proper care when
changing lanes may result in
injury, death, or vehicle damage.
Before making a lane change,
always check mirrors, glance over
your shoulder, and use the turn
signals.
LCA Detection Zones
1. SBZA Detection Zone
2. LCA Detection Zone
The LCA sensor covers a zone of
approximately one lane over from
both sides of the vehicle, or 3.5 m
(11 ft). The height of the zone is
approximately between 0.5 m (1.5 ft)
and 2 m (6 ft) off the ground. The
Side Blind Zone Alert (SBZA)
warning area starts at approximately
the middle of the vehicle and goes
back 5 m (16 ft). Drivers are also
warned of vehicles rapidly
approaching from up to 25 m (82 ft)
behind the vehicle.
How the System Works
The LCA symbol lights up in the
side mirrors when the system
detects a moving vehicle in the next
lane over that is in the side blind
zone or rapidly approaching that
zone from behind. A lit LCA symbol
indicates it may be unsafe to
change lanes. Before making a lane
change, check the LCA display,
check mirrors, glance over your
shoulder, and use the turn signals.
Left Side Mirror DisplayRight Side Mirror Display
When the vehicle is started, both
outside mirror LCA displays will
briefly come on to indicate the
system is operating. When the
vehicle is in a forward gear, the left
or right side mirror display will light
up if a moving vehicle is detected in
the next lane over in that blind zone
or rapidly approaching that zone.
If the turn signal is activated in the
same direction as a detected
vehicle, this display will flash as an
extra warning not to change lanes.
LCA is disabled when the trailer
connection status is displayed.
A DIC message may display. The
SBZA system still operates.
LCA can be disabled through
vehicle personalization. When you
disable LCA, SBZA is also disabled.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
298 Driving and Operating
Vehicle SeriesTrailer WeightWeight-Distributing Hitch
Usage Hitch Distribution
1500 Up to 3 175 kg (7,000 lb) Not Required 50%
1500 Over 3 175 kg (7,000 lb) Required50%
2500/3500 Up to 9 080 kg (20,000 lb) Not Required 25%
1. Front of Vehicle
2. H1/H2 Body to Ground
Distance
Towing with Model 1500 Trucks
1. Position the truck so that the trailer is ready to connect.
Keep the trailer detached.
2. Measure the height of the top of the front wheel opening at
the fender to the ground (H1).
3. Attach the vehicle to the trailer. Do not attach weight
distribution bars at this time.
4. Measure the height of the top of the front wheel opening on
the fender to the ground (H2). 5. Install and adjust the tension in
the weight-distributing bars per
the manufacturers’
recommendations so that the
height of the front fender is
approximately H2−[(H2−H1)/2]
(halfway between the two
measured ride heights).
6. Visually inspect the trailer and weight-distributing hitch to
ensure that the manufacturers’
recommendations have
been met.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 299
MeasurementHeight Example 1500 (mm)
H1 1 000
H2 1 050
H2−H1 50
(H2−H1)/2 25
H2−[(H2−H1)/2] 1 025
Towing with Model 2500/3500
Trucks 1. Position the truck so that the trailer is ready to connect.
Keep the trailer detached.
2. Measure the height of the top of the front wheel opening at
the fender to the ground (H1).
3. Attach the vehicle to the trailer. Do not attach weight
distribution bars at this time.
4. Measure the height of the top of the front wheel opening on
the fender to the ground (H2). 5. Install and adjust the tension in
the weight-distributing bars per
the manufacturers’
recommendations so that the
height of the front fender is
approximately H2−[(H2−H1)/4]
(1/4 the difference between the
two measured ride heights,
below the secondary ride
height {H2}).
6. Visually inspect the trailer and weight-distributing hitch to
ensure that the manufacturers’
recommendations have
been met.