2021 GMC SIERRA tow

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Seats and Restraints 91
4. Pull the shoulder belt all the way out ofthe retractor to set the lock. When the
retractor lock is set, the belt can be
tightened but not pulled out of the
retractor.5. 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 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) 077 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) 077.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
94 Seats and Restraints
5. Pull the shoulder belt all the way out ofthe retractor to set the lock. When the
retractor lock is set, the belt can be
tightened but not pulled out of the
retractor.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. If the vehicle does not have a rear seat
and the child restraint manufacturer
recommends using a top tether anchor,
attach the top tether to the top tether
anchor. Refer to the instructions that
came with the child restraint and to
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.
If the airbag is off, the OFF indicator in the
passenger airbag status indicator will come
on and stay on when the vehicle is started.
If a child restraint has been installed and
the ON indicator is lit, see “If the On
Indicator Is Lit for a Child Restraint” under
Passenger Sensing System 066.
To remove the child restraint, unbuckle the
vehicle seat belt and let it return to the
stowed position.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
96 Storage
Underseat Storage
There may be storage under the rear
passenger seat. Lift up on the seat bench to
access. Push the seat bench toward the floor
to close.
Rear Storage
There may be storage in the rear seat. Pull
the tab to access.
Push the storage door to close. The storage
door must be closed before installing child
restraints.
Center Console Storage
Bench Seat
Pull the strap on the side of the center
seatback to access the storage area and
cupholders. Do not use the center seatback
as a seating position when the seatback is
folded down.
To raise the seatback, push the seatback
rearward until it locks in the upright
position. Push and pull on the seatback to
make sure it is locked.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Instruments and Controls 99
Instruments and Controls
Controls
Steering Wheel Adjustment . . . . . . . . . . . 100
Steering Wheel Controls . . . . . . . . . . . . . . 100
Heated Steering Wheel . . . . . . . . . . . . . . . . 100
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Windshield Wiper/Washer . . . . . . . . . . . . . 101
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Power Outlets . . . . . . . . . . . . . . . . . . . . . . . . . 102
Wireless Charging . . . . . . . . . . . . . . . . . . . . . 103
Warning Lights, Gauges, and Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Instrument Cluster . . . . . . . . . . . . . . . . . . . . 106
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . . 110
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Fuel Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Engine Oil Pressure Gauge . . . . . . . . . . . . . 111
Engine Coolant Temperature Gauge . . . . 112
Voltmeter Gauge . . . . . . . . . . . . . . . . . . . . . . . 113
Seat Belt Reminders . . . . . . . . . . . . . . . . . . . . 113
Airbag Readiness Light . . . . . . . . . . . . . . . . . 114
Passenger Airbag Status Indicator . . . . . . 114
Charging System Light . . . . . . . . . . . . . . . . . 115 Malfunction Indicator Lamp (Check
Engine Light) . . . . . . . . . . . . . . . . . . . . . . . . . 115
Brake System Warning Light . . . . . . . . . . . 117
Electric Parking Brake Light . . . . . . . . . . . . 117
Service Electric Parking Brake Light . . . . 118
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Four-Wheel-Drive Light . . . . . . . . . . . . . . . . . 118
Tow/Haul Mode Light . . . . . . . . . . . . . . . . . 119
Hill Descent Control Light . . . . . . . . . . . . . . 119
Lane Keep Assist (LKA) Light . . . . . . . . . . . 119
Vehicle Ahead Indicator . . . . . . . . . . . . . . . . 119
Pedestrian Ahead Indicator . . . . . . . . . . . . 119
Traction Off Light . . . . . . . . . . . . . . . . . . . . . . 120
Traction Control System (TCS)/Electronic Stability Control Light . . . . . . . . . . . . . . . 120
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Driver Mode Control Light . . . . . . . . . . . . . 121
Tire Pressure Light . . . . . . . . . . . . . . . . . . . . . 122
Engine Oil Pressure Light (Uplevel Cluster) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Low Fuel Warning Light . . . . . . . . . . . . . . . . 122
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . 122
High-Beam On Light . . . . . . . . . . . . . . . . . . . 123
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . 123
Lamps On Reminder . . . . . . . . . . . . . . . . . . . 123
Cruise Control Light . . . . . . . . . . . . . . . . . . . . 123 Door Ajar Light . . . . . . . . . . . . . . . . . . . . . . . . 124
Information Displays
Driver Information Center (DIC) (Base
Level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Driver Information Center (DIC) (Midlevel and Uplevel) . . . . . . . . . . . . . . . 125
Head-Up Display (HUD) . . . . . . . . . . . . . . . . 128
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . . . . . . . . . . . 130
Engine Power Messages . . . . . . . . . . . . . . . . 131
Vehicle Speed Messages . . . . . . . . . . . . . . . 131
Vehicle Personalization
Vehicle Personalization . . . . . . . . . . . . . . . . . 131
Universal Remote System
Universal Remote System . . . . . . . . . . . . . 136
Universal Remote System Programming . . . . . . . . . . . . . . . . . . . . . . . . 136
Universal Remote System Operation . . . 138

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
116 Instruments and Controls
Caution
If the vehicle is driven continually with
this light on, the emission control system
may not work as well, the fuel economy
may be lower, and the vehicle may not
run smoothly. This could lead to costly
repairs that might not be covered by the
vehicle warranty.
Caution
Modifications to the engine, transmission,
exhaust, intake, or fuel system, or the
use of replacement tires that do not
meet the original tire specifications, can
cause this light to come on. This could
lead to costly repairs not covered by the
vehicle warranty. This could also affect
the vehicle’s ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications0323.
If the light is flashing : A malfunction has
been detected that could damage the
emission control system and increase vehicle
emissions. Diagnosis and service may be
required. To help prevent damage, reduce vehicle
speed and avoid hard accelerations and
uphill grades. If towing a trailer, reduce the
amount of cargo being hauled as soon as
possible.
If the light continues to flash, find a safe
place to park. Turn the vehicle off and wait
at least 10 seconds before restarting the
engine. If the light is still flashing, follow
the previous guidelines and see your dealer
for service as soon as possible.
If the light is on steady :
A malfunction has
been detected. Diagnosis and service may be
required.
Check the following:
.If fuel has been added to the vehicle
using the capless funnel adapter, make
sure that it has been removed. See
“Filling the Tank with a Portable
Gas Can” underFilling the Tank (Pickup
Model) 0285 or
Filling the Tank (Chassis Cab Model) 0287. The diagnostic system can
detect if the adapter has been left
installed in the vehicle, allowing fuel to
evaporate into the atmosphere. A few
driving trips with the adapter removed
may turn off the light.
.Poor fuel quality can cause inefficient
engine operation and poor driveability,
which may go away once the engine is
warmed up. If this occurs, change the fuel
brand. It may require at least one full
tank of the proper fuel to turn the light
off. See Recommended Fuel (Except 6.2L
V8 Engine) 0283 or
Recommended Fuel (6.2L V8 Engine)
0 284.
If the light remains on, see your dealer.
Emissions Inspection and Maintenance
Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument panel to
the left of the steering wheel. Connecting
devices that are not used to perform an
Emissions Inspection/Maintenance test or to

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Instruments and Controls 117
service the vehicle may affect vehicle
operation. SeeAdd-On Electrical Equipment
0 318. See your dealer if assistance is
needed.
The vehicle may not pass inspection if:
.The light is on when the engine is
running.
.The light does not come on when the
ignition is on while the engine is off.
.Critical emission control systems have not
been completely diagnosed. If this
happens, the vehicle would not be ready
for inspection and might require
several days of routine driving before the
system is ready for inspection. This can
happen if the 12-volt battery has recently
been replaced or run down, or if the
vehicle has been recently serviced.
See your dealer if the vehicle will not pass
or cannot be made ready for the test.
Brake System Warning Light
MetricEnglish
This light should come on briefly when the
vehicle is turned on. If it does not come on
then, have it fixed so it will be ready to
warn you if there is a problem.
If the light comes on and stays on at start
up, there is a brake problem. Have the brake
system inspected right away.
If the light comes on while driving, pull off
the road and stop carefully. If equipped with
electric brake boost, vehicle speed may be
limited when the brake system warning
light comes on. The brake pedal might be
harder to push, or the brake pedal may go
closer to the floor. It could take longer to
stop. If the light is still on, have the vehicle
towed for service. See Towing the Vehicle
0 394.
{Warning
The brake system might not be working
properly if the brake system warning
light is on. Driving with the brake system
warning light on can lead to a crash.
If the light is still on after the vehicle has
been pulled off the road and carefully
stopped, have the vehicle towed for
service.
Electric Parking Brake Light
MetricEnglish
This light comes on when the parking brake
is applied. If the light continues flashing
after the parking brake is released, or while
driving, there is a problem with the Electric
Parking Brake system. A message may also
display in the Driver Information
Center (DIC).
If the light does not come on, or remains
flashing, see your dealer.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Instruments and Controls 119
Tow/Haul Mode Light
For vehicles with the Tow/Haul Mode
feature, this light comes on when the Tow/
Haul Mode has been activated.
SeeTow/Haul Mode 0242.
Hill Descent Control Light
If equipped, the Hill Descent Control light
comes on when the system is ready for use.
When the light flashes, the system is active.
See Hill Descent Control (HDC) 0250.
Lane Keep Assist (LKA) Light
After the vehicle is started, this light turns
off and stays off if LKA has not been turned
on or is unavailable.
If equipped, this light is white if LKA is
turned on, but not ready to assist. This light
is green if LKA is turned on and is ready to
assist.
LKA may assist by gently turning the
steering wheel if the vehicle approaches a
detected lane marking. The LKA light is
amber when assisting.
This light flashes amber as a Lane Departure
Warning (LDW) alert, to indicate that the
lane marking has been crossed.
LKA will not assist or alert if the turn signal
is active in the direction of lane departure,
or if LKA detects that you are accelerating,
braking, or actively steering.
See Lane Keep Assist (LKA) 0281.
Vehicle Ahead Indicator
If equipped, this indicator will display green
when a vehicle is detected ahead and amber
when you are following a vehicle ahead
much too closely.
See Forward Collision Alert (FCA) System
0 275.
Pedestrian Ahead Indicator
If equipped, this indicator will display amber
when a nearby pedestrian is detected in
front of the vehicle.
See Front Pedestrian Braking (FPB) System
0 278.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
128 Instruments and Controls
Head-Up Display (HUD)
{Warning
If the HUD image is too bright or too
high in your field of view, it may take
you more time to see things you need to
see when it is dark outside. Be sure to
keep the HUD image dim and placed low
in your field of view.
If equipped with HUD, some information
about the operation of the vehicle is
projected onto the windshield. The image is
projected through the HUD lens on top of
the instrument panel. The information
appears as an image focused out toward the
front of the vehicle.
Caution
If you try to use the HUD image as a
parking aid, you may misjudge the
distance and damage your vehicle. Do not
use the HUD image as a parking aid.
The HUD information can be displayed in
various languages. The speedometer reading
and other numerical values can be displayed
in either English or metric units. The language selection is changed through
the radio, and the units of measurement is
changed through the instrument cluster. See
Settings
0186 and “Options” under
Instrument Cluster 0106.
HUD Display on the Windshield
Depending on how the vehicle is equipped,
the HUD may display some of the following
vehicle information and vehicle messages or
alerts:
.Speed
.Audio
.Phone
.Navigation
.Driver Assistance Features
.Vehicle Messages Some vehicle messages or alerts displayed in
the HUD may be cleared by using the
steering wheel controls.
The HUD control is to the left of the
steering wheel.
To adjust the HUD image:
1. Adjust the driver seat.
2. Start the engine.
3. Use the following settings to adjust the HUD.
$:Press or pull to center the HUD image.
The HUD image can only be adjusted up and
down, not side to side.
!: Press to select the display view. Each
press will change the display view.