tow GMC SIERRA 2020 Owner's Guide

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
112 Seats and Restraints
If a child restraint has been installed
and the ON indicator is lit, see“If
the On Indicator Is Lit for a Child
Restraint” underPassenger Sensing
System 078.
To remove the child restraint,
unbuckle the vehicle seat belt and
let it return to the stowed position.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
114 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 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 139
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 Modifications
0329.
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”
under Filling the Tank (Pickup
Model) 0283 or
Filling the Tank (Chassis Cab
Model) 0285. 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) 0280 or
Recommended Fuel (6.2L
V8 Engine) 0281.
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).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
140 Instruments and Controls
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
service the vehicle may affect
vehicle operation. SeeAdd-On
Electrical Equipment 0322. 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
0424.
{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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
142 Instruments and Controls
If both the ABS warning light and
the brake system warning light are
on, ABS is not functioning and there
is a problem with the regular brakes.
See your dealer for service.
SeeBrake System Warning Light
0 140.
Four-Wheel-Drive Light
Auto Mode Shown, Other Modes
Similar
If equipped, the four-wheel-drive
light displays what mode the vehicle
is in. The light will show each mode:
2WD, 4HI, AUTO (all transfer
cases); 4LOW and N (two-speed
transfer case only).
The light will flash when a shift is in
progress. Once the shift is complete
the light will be steady. If the light turns amber, there may
be a malfunction with the
four-wheel-drive system. See your
dealer.
See
Four-Wheel Drive 0227.
Tow/Haul Mode Light
For vehicles with the Tow/Haul
Mode feature, this light comes on
when the Tow/Haul Mode has been
activated.
See Tow/Haul Mode 0226.
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)
0 237.
Lane Departure Warning
(LDW) Light (2500/3500
Series)
If equipped, this light comes on
briefly while starting the vehicle. If it
does not come on, have the vehicle
serviced.
This light is green if LDW is on and
ready to operate.
This light changes to amber and
flashes to indicate that the lane
marking has been crossed without
using a turn signal in that direction.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Instruments and Controls 153
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” in the infotainment
manual and “Options”under
Instrument Cluster 0127.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
158 Instruments and Controls
Touch Beeps or Safety Alert Seat.
Forward Collision System
This setting controls the vehicle
response when detecting a vehicle
ahead of you. The Off setting
disables all FCA and AEB functions.
With the Alert and Brake setting,
both FCA and AEB are available.
The Alert setting disables AEB. See
Automatic Emergency Braking
(AEB)0270.
Touch Off, Alert, or Alert and Brake.
Front Pedestrian Detection
This feature may help avoid or
reduce the harm caused by
front-end crashes with nearby
pedestrians. See Front Pedestrian
Braking (FPB) System (1500 Series)
0 272.
Touch Off, Alert, or Alert and Brake.
Adaptive Cruise Go Notifier
This setting determines if an alert
will appear when Adaptive Cruise
Control brings the vehicle to a
complete stop and the vehicle ahead of you starts moving again.
See
Adaptive Cruise Control (1500
Series) 0245.
Touch Off or On.
Lane Change Alert
This allows the feature to be turned
on or off. See Lane Change Alert
(LCA) 0274.
Touch Off or On.
Park Assist
This allows the feature to be turned
on or off. See Assistance Systems
for Parking or Backing 0257.
Select Off, On, or On with Towbar.
Rear Camera Park Assist Symbols
This setting enables the Rear
Camera Park Assist Symbols. See
Assistance Systems for Parking or
Backing 0257.
Touch Off or On. Rear Cross Traffic Alert
This allows the Rear Cross Traffic
Alert feature to be turned on or off.
See
Assistance Systems for Parking
or Backing 0257.
Touch Off or On.
Comfort and Convenience
Touch and the following may
display:
. Chime Volume
. Reverse Tilt Mirror
. Remote Mirror Folding
Chime Volume
This determines the chime volume
level.
Touch the controls on the
infotainment display to adjust the
volume.
Reverse Tilt Mirror
This allows the feature to be turned
on or off. See Reverse Tilt Mirrors
0 45.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Lighting 167
Keep this area of the windshield
clear of debris to allow for best
system performance.
The high-beam headlamps remain
on, under the automatic control,
until one of the following situations
occurs:
.The system detects an
approaching vehicle's
headlamps.
. The system detects a preceding
vehicle's taillamps.
. The outside light is bright
enough that high-beam
headlamps are not required.
. The vehicle's speed drops below
20 km/h (12 mph).
. The IntelliBeam system is
disabled by the button on the
turn signal lever. If this happens,
press the button on the end of
the turn signal lever when the
exterior lamp control is in the
AUTO or
2position. The
instrument cluster light will come
on to indicate the IntelliBeam is reactivated. See
Headlamp
High/Low-Beam Changer 0167
and
Flash-to-Pass 0168.
The high beams may not turn off
automatically if the system cannot
detect another vehicle's lamps
because of any of the following:
. The other vehicle's lamps are
missing, damaged, obstructed
from view, or otherwise
undetected.
. The other vehicle's lamps are
covered with dirt, snow, and/or
road spray.
. The other vehicle's lamps cannot
be detected due to dense
exhaust, smoke, fog, snow, road
spray, mist, or other airborne
obstructions.
. The vehicle's windshield is dirty,
cracked, or obstructed by
something that blocks the view
of the light sensor. .
The vehicle is loaded such that
the front end points upward,
causing the light sensor to aim
high and not detect headlamps
and taillamps.
. Driving on winding or hilly roads.
The automatic high-beam
headlamps may need to be disabled
if any of the above conditions exist.
Exterior Lamps Off
Reminder
A reminder chime sounds when the
headlamps or parking lamps are
manually turned on, the ignition is
off, and a door is open. To disable
the chime, turn the lamps off.
Headlamp High/
Low-Beam Changer
Push the turn signal lever toward
the instrument panel to change the
headlamps from low to high beam.
Pull or push the turn signal lever to
return to low-beam headlamps.