2020 GMC SIERRA warning

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
104 Seats and Restraints
Head Restraint or Headrest
Removal and Reinstallation
The second row outboard head
restraints or center headrest can be
removed if they interfere with the
proper installation of the child
restraint.
To remove the second row head
restraints or center headrest:
1. Press both buttons on the headrestraint or headrest posts at
the same time, and pull up on
the head restraint or headrest.
2. Store the head restraint or headrest in a secure place. 3. When the child restraint is
removed, reinstall the head
restraint or headrest before the
seating position is used.
{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.
To reinstall the head restraint or
headrest:
1. Insert the head restraint or headrest posts into the holes in
the top of the seatback. The
notches on the posts must face
the driver side of the vehicle.
2. Push the head restraint or headrest down.
3. Try to move the head restraint or headrest to make sure that it
is locked in place.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 105
Replacing LATCH System
Parts After a Crash
{Warning
A crash can damage the LATCH
system in the vehicle. A damaged
LATCH system may not properly
secure the child restraint,
resulting in serious injury or even
death in a crash. To help make
sure the LATCH system is
working properly after a crash,
see your dealer to have the
system inspected and any
necessary replacements made as
soon as possible.
If the vehicle has the LATCH system
and it was being used during a
crash, new LATCH system parts
may be needed.
New parts and repairs may be
necessary even if the LATCH
system was not being used at the
time of the crash.
Securing Child Restraints
(With the Seat Belt in the
Rear Seat)
When securing a child restraint with
the seat belts in a rear seat position,
study the instructions that came with
the child restraint to make sure it is
compatible with this vehicle.
If the child restraint has the LATCH
system, see Lower Anchors and
Tethers for Children (LATCH
System) 092 for how and where to
install the child restraint using
LATCH. If a child restraint is secured
in the vehicle using a seat belt and
it uses a top tether, see Lower
Anchors and Tethers for Children
(LATCH System) 092 for top tether
anchor locations.
Do not secure a child seat in a
position without a top tether anchor
if a national or local law requires
that the top tether be anchored, or if
the instructions that come with the
child restraint say that the top tether
must be anchored. In Canada, the law requires that
forward-facing child restraints have
a top tether, and that the tether be
attached.
If the child restraint or vehicle seat
position does not have the LATCH
system, you will be using the seat
belt to secure the child restraint. Be
sure to follow the instructions that
came with the child restraint.
If more than one child restraint
needs to be installed in the rear
seat, be sure to read
Where to Put
the Restraint 091.
Double Cab
1. Remove the head restraint or
headrest prior to installing a
forward-facing child restraint in
an outboard rear seating
position. See “Head Restraint
or Headrest Removal and
Reinstallation” underLower
Anchors and Tethers for
Children (LATCH System) 092.
2. Put the child restraint on the seat.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
108 Seats and Restraints
5. To tighten the belt, push downon the child 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 4 and 5. 6. If the child restraint has a top
tether, follow the child restraint
manufacturer's instructions
regarding the use of the top
tether. See Lower Anchors and
Tethers for Children (LATCH
System) 092 for more
information on using the top
tether anchors.
7. 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.
For outboard rear seating positions,
if the child restraint cannot be
installed properly with the head
restraint in place, the head restraint may be removed. See your dealer
for assistance with removal, and
store the removed head restraint in
a secure place. When the child
restraint is removed, reinstall the
head restraint before the seating
position is used. For reinstallation
instructions, see
“Head Restraint or
Headrest Removal and
Reinstallation” underLower Anchors
and Tethers for Children (LATCH
System) 092.Securing Child Restraints
(In the Center Front Seat)
{Warning
A child in a child restraint in the
center front seat can be badly
injured or killed by the frontal
airbags if they inflate. Never
secure a child restraint in the
center front seat. It is always
better to secure a child restraint in
a rear seat.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Seats and Restraints 109
Do not use child restraints in the
center front seat position.
Securing Child Restraints
(With the Seat Belt in the
Front Outboard Seat)
This vehicle has airbags. A rear
seat is a safer place to secure a
forward-facing child restraint. See
Where to Put the Restraint091.
In addition, the vehicle has a
passenger sensing system which is
designed to turn off the front
outboard passenger frontal airbag
under certain conditions. See
Passenger Sensing System 078
and
Passenger Airbag Status Indicator
0 137 for more information,
including important safety
information.
Never put a rear-facing child
restraint in the front. This is because
the risk to the rear-facing child is so
great, if the airbag deploys.
{Warning
A child in a rear-facing child
restraint can be seriously injured
or killed if the front outboard
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 front
outboard passenger frontal airbag
inflates and the passenger seat is
in a forward position.
Even if the passenger sensing
system has turned off the front
outboard passenger frontal
airbag, no system is fail-safe. No
one can guarantee that an airbag
will not deploy under some
unusual circumstance, even
though it is turned off.
Secure rear-facing child restraints
in a rear seat, even if the airbag
is off. If you secure a
(Continued)
Warning (Continued)
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 the child restraint in a
rear seat.
SeePassenger Sensing System
0 78 for additional information.
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.
If the child restraint uses a top
tether, see Lower Anchors and
Tethers for Children (LATCH
System) 092 for top tether anchor
locations.
Do not secure a child seat in a
position without a top tether anchor
if a national or local law requires
that the top tether be anchored, or if

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Storage 113
Storage
Storage Compartments
Storage Compartments . . . . . . . 113
Glove Box . . . . . . . . . . . . . . . . . . . . 113
Cupholders . . . . . . . . . . . . . . . . . . . 113
Underseat Storage . . . . . . . . . . . 114
Rear Storage . . . . . . . . . . . . . . . . . 114
Center Console Storage . . . . . . 114
Floor Console Storage . . . . . . . . 115
Additional Storage Features
Cargo Tie-Downs . . . . . . . . . . . . . 116
Storage
Compartments
{Warning
Do not store heavy or sharp
objects in storage compartments.
In a crash, these objects may
cause the cover to open and
could result in injury.
Glove Box
To access the upper glove box, pull
up on the handle.To access the lower glove box,
unlock with the key and pull down
on the handle.
Cupholders
Front
There may be cupholders on the
center front seat console armrest.
Rear
If equipped, pull the rear seat
armrest down to access the
cupholders.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
118 Instruments and Controls
Instruments and
Controls
Controls
Steering Wheel Adjustment . . . 119
Steering Wheel Controls . . . . . . 120
Heated Steering Wheel . . . . . . . 120
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Windshield Wiper/Washer . . . . 120
Compass . . . . . . . . . . . . . . . . . . . . . 121
Clock . . . . . . . . . . . . . . . . . . . . . . . . . 121
Power Outlets . . . . . . . . . . . . . . . . 122
Wireless Charging . . . . . . . . . . . . 124
Warning Lights, Gauges, and
Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . 126
Instrument Cluster . . . . . . . . . . . . 127
Speedometer . . . . . . . . . . . . . . . . . 131
Odometer . . . . . . . . . . . . . . . . . . . . . 132
Trip Odometer . . . . . . . . . . . . . . . . 132
Tachometer . . . . . . . . . . . . . . . . . . . 132
Fuel Gauge . . . . . . . . . . . . . . . . . . . 132
Engine Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . . . 133
Engine Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 134 Voltmeter Gauge . . . . . . . . . . . . . 135
Seat Belt Reminders . . . . . . . . . 136
Airbag Readiness Light . . . . . . . 136
Passenger Airbag Status
Indicator . . . . . . . . . . . . . . . . . . . . 137
Charging System Light . . . . . . . 138
Malfunction Indicator Lamp (Check Engine Light) . . . . . . . . 138
Brake System Warning Light . . . . . . . . . . . . . . . . . . . . . . . . 140
Electric Parking Brake Light . . . . . . . . . . . . . . . . . . . . . . . . 141
Service Electric Parking Brake Light . . . . . . . . . . . . . . . . . . . . . . . . 141
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . 141
Four-Wheel-Drive Light . . . . . . . 142
Tow/Haul Mode Light . . . . . . . . . 142
Hill Descent Control Light . . . . 142
Lane Departure Warning (LDW) Light (2500/3500
Series) . . . . . . . . . . . . . . . . . . . . . . 142
Lane Keep Assist (LKA) Light (1500 Series) . . . . . . . . . . . . . . . 143
Vehicle Ahead Indicator . . . . . . 143
Pedestrian Ahead Indicator . . . 143
Traction Off Light . . . . . . . . . . . . . 143
Traction Control System (TCS)/ Electronic Stability Control
Light . . . . . . . . . . . . . . . . . . . . . . . . 144 Electronic Stability Control
(ESC) Off Light . . . . . . . . . . . . . . 144
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . 145
Driver Mode Control Light . . . . 145
Tire Pressure Light . . . . . . . . . . . 145
Engine Oil Pressure Light
(Uplevel Cluster) . . . . . . . . . . . . 146
Low Fuel Warning Light . . . . . . 146
Security Light . . . . . . . . . . . . . . . . . 147
High-Beam On Light . . . . . . . . . . 147
Front Fog Lamp Light . . . . . . . . . 147
Lamps On Reminder . . . . . . . . . 147
Cruise Control Light . . . . . . . . . . 147
Door Ajar Light . . . . . . . . . . . . . . . 148
Information Displays
Driver Information Center (DIC) (Base Level) . . . . . . . . . . . . . . . . 148
Driver Information Center (DIC) (Midlevel and Uplevel) . . . . . . 149
Head-Up Display (HUD) . . . . . . 152
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . 156
Engine Power Messages . . . . . 156
Vehicle Speed Messages . . . . . 156
Vehicle Personalization
Vehicle Personalization . . . . . . . 157

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Instruments and Controls 121
depending on how long the
windshield washer had been
activated. SeeWasher Fluid0354
for information on filling the
windshield washer fluid reservoir.
Clear snow and ice from the wiper
blades before using them. If frozen
to the windshield, carefully loosen or
thaw them. Damaged blades should
be replaced. See Wiper Blade
Replacement 0364.
Heavy snow or ice can overload the
wiper motor.
{Warning
In freezing weather, do not use
the washer until the windshield is
warmed. Otherwise the washer
fluid can form ice on the
windshield, blocking your vision.
{Warning
Before driving the vehicle, always
clear snow and ice from the hood,
windshield, roof, and rear of the
vehicle, including all lamps and
windows. Reduced visibility from
snow and ice buildup could lead
to a crash.
Wipe Parking
If the ignition is turned off while the
wipers are on LO, HI, or
3, they
will immediately stop.
If the windshield wiper control is ON
then moved to OFF before the driver
door is opened or within 10 minutes,
the wipers will restart and move to
the base of the windshield.
If the ignition is turned off while the
wipers are performing wipes due to
windshield washing, the wipers
continue to run until they reach the
base of the windshield.
Compass
The vehicle may have a compass
display on the Driver Information
Center (DIC). The compass receives
its heading and other information
from the Global Positioning
System (GPS) antenna, Electronic
Stability Control (ESC), and vehicle
speed information.
The compass system is designed to
operate for a certain number of
miles or degrees of turn before
needing a signal from the GPS
satellites. When the compass
display shows CAL, drive the
vehicle for a short distance in an
open area where it can receive a
GPS signal. The compass system
will automatically determine when a
GPS signal is restored and provide
a heading again.
Clock
The time and date for the clock can
be set using the infotainment
system. See “Time/Date”in
“System” under“Settings” in the
infotainment manual.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
122 Instruments and Controls
Power Outlets
Accessory power outlets can be
used to plug in electrical equipment,
such as a cell phone or MP3 player.
Rear of Front Center Console
The vehicle has one accessory
power outlet under the climate
control system and one accessory
power outlet on the rear of the
center console, if equipped, or on
the rear of the bench seat,
if equipped.
Lift the cover to access and replace
when not in use.
{Warning
Power is always supplied to the
outlets. Do not leave electrical
equipment plugged in when the
vehicle is not in use because the
vehicle could catch fire and cause
injury or death.
Caution
Leaving electrical equipment
plugged in for an extended period
of time while the vehicle is off will
drain the battery. Always unplug
electrical equipment when not in
use and do not plug in equipment
that exceeds the maximum
15 amp rating.
Certain power accessory plugs may
not be compatible with the
accessory power outlet and could
overload vehicle or adapter fuses.
If a problem is experienced, see
your dealer. When adding electrical equipment,
be sure to follow the proper
installation instructions included with
the equipment. See
Add-On
Electrical Equipment 0322.
Caution
Hanging heavy equipment from
the power outlet can cause
damage not covered by the
vehicle warranty. The power
outlets are designed for
accessory power plugs only, such
as cell phone charge cords.
Power Outlet 110/120-Volt
Alternating Current
If equipped, the vehicle has two
alternating current power outlets.