front end GMC SIERRA 2021 Owner's Guide

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/6/20
146 Lighting
+ON/OFF :Press to turn the dome lamps
on manually. Press again to turn the dome
lamps off.
Reading Lamps
There are reading lamps on the overhead
console and over the rear seats. These lamps
come on when any door is opened.
To operate, the ignition must be on, or in
ACC/ACCESSORY, or using Retained Accessory
Power (RAP).
Front Reading Lamps
The front reading lamps are in the overhead
console. Press the lamp lenses to turn the front
reading lamps on or off.
Rear Reading Lamps
The rear reading lamps are over the rear
seats.
Press the lamp lens to turn the rear reading
lamps on or off.
Lighting Features
Entry Lighting
Some exterior lamps turn on briefly at
night, or in areas with limited lighting,
when
Kis pressed on the remote key. After
about 30 seconds the exterior lamps turn
off. When any door is opened or the remote
unlock is pressed, all interior lights turn on
and then interior lamps dim to off after
20 seconds. The entry lighting feature for exterior
lighting can be changed. See
“Vehicle
Locator Lights” underVehicle Personalization
0 131.
Exit Lighting
Some exterior lamps come on at night, or in
areas with limited lighting, when the driver
door is opened after the ignition is turned
off. The dome lamp comes on when any
door is opened or after the ignition is
turned off. The exterior lamps and dome
lamp remain on after the door is closed for
a set amount of time, then automatically
turn off.
The exterior lamps turn off immediately by
turning the exterior lamp control off.
The exit lighting for exterior lights can be
changed. See Vehicle Personalization 0131.
Battery Load Management
The vehicle has Electric Power Management
(EPM), which estimates the battery's
temperature and state of charge. It then
adjusts the voltage for best performance
and extended life of the battery.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
172 Infotainment System
Show POI Icons
To see the POI categories, touch Options,
then touch Show on Map. Up to eight
categories of icons can be selected.
Smart POI Icons on Map (If Equipped)
The smart POI icons such as fuel stations
and parking may appear based on time,
location, driver search behavior, driving
conditions, and vehicle conditions.
Touch a smart POI icon to open the
corresponding details:
.Left side: Name and address of the POI.
.Right side:E+ ETE (Estimated Time
Enroute.)
Smart Fuel Station Icons
Fuel station prices are shown if available for
nearby stations when the vehicle is low
on fuel. Smart Parking Icons
When reaching a densely populated
destination and the system determines that
parking may be limited, the system will
attempt to display nearby parking
destinations with pricing information,
if available.
Report an Issue Using POI Details (If
Equipped)
In the POI details page, a POI issue can be
reported if the data is not accurate or the
address is incorrect. Touch Report an Issue
near the bottom of the display to access the
issue selection page. Touch one of the
predefined issues on the selection page,
then touch Send. The system will send the
information for analysis.
Search
Touch Search on the infotainment display to
open the search display. It has a search field
entry box, quick category icon shortcuts,
recents icon, favorites icon, and keyboard.
Auto Complete
Enter a partial location in the field entry box
on the search display. Auto complete will
attempt to complete the destination based
on what is being entered. Touch the
suggested item to search.
Search While in Motion with No Front Seat
Passenger Present
The search display will not allow changes or
text input with the keyboard when the
vehicle is in motion. As a result, a display
showing three rows of the most commonly
used categories appears. Touching the search
box will activate speech recognition.
Search While in Motion with Front Seat
Passenger Present
If the system detects that the front seat
passenger is present with both driver and
passenger seat belts buckled, touching the
search icon will display an alert message
that allows the passenger to search for a
destination as if the vehicle were stopped.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Infotainment System 181
.Review the controls and operation of the
infotainment system.
.Pair mobile device(s) to the vehicle. The
system may not work with all mobile
devices. See“Pairing”later in this section.
Vehicles with a Bluetooth system can use a
Bluetooth-capable mobile device with a
Hands-Free Profile to make and receive
phone calls. The infotainment system and
voice recognition are used to control the
system. The system can be used while the
ignition is on or in ACC/ACCESSORY. The
range of the Bluetooth system can be up to
9.1 m (30 ft). Not all mobile devices support
all functions and not all mobile devices work
with the Bluetooth system. See my.gmc.com
for more information about compatible
mobile devices.
Controls
Use the controls on the center stack and the
steering wheel to operate the Bluetooth
system.
Steering Wheel Controls
g: Press to answer incoming calls and start
voice recognition on your connected
Bluetooth mobile device.
i: Press to end a call, decline a call,
or cancel an operation. Press to mute or
unmute the infotainment system when not
on a call.
Infotainment System Controls
For information about how to navigate the
menu system using the infotainment
controls, see Using the System 0152.
Audio System
When using the Bluetooth mobile device
system, sound comes through the vehicle's
front audio system speakers and overrides
the audio system. The volume level while on
a mobile device call can be adjusted by
pressing the steering wheel controls or the
volume control on the center stack. The
adjusted volume level remains in memory
for later calls. The volume cannot be
lowered beyond a certain level.
Bluetooth (Pairing and Using a
Phone)
Pairing
A Bluetooth-enabled mobile device must be
paired to the Bluetooth system and then
connected to the vehicle before it can be used. See the mobile device manufacturer's
user guide for Bluetooth functions before
pairing the device.
Pairing Information
.If no mobile device has been connected,
the Phone main page on the infotainment
display will show the Connect Phone
option. Touch this option to connect.
Another way to connect is to touch the
Phones tab at the top right of the display
and then touch Add Phone.
.A Bluetooth smartphone with music
capability can be paired to the vehicle as
a smartphone and a music player at the
same time.
.Up to 10 devices can be paired to the
Bluetooth system.
.The pairing process is disabled when the
vehicle is moving.
.Pairing only needs to be completed once,
unless the pairing information on the cell
phone changes or the cell phone is
deleted from the system.
.If multiple paired cell phones are within
range of the system, the system connects
to the paired cell phone that is set to
First to Connect. If there is no cell phone
set to First to Connect, it will link to the

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Climate Controls 207
The fan, air delivery mode, air conditioning,
driver and passenger temperatures, and Sync
settings can be controlled by touching
CLIMATE on the infotainment Home Page or
the climate button in the climate control
display application tray. A selection can then
be made on the front climate control page
displayed.
Climate Control Status Display
The climate control status display appears
briefly when the center stack climate
controls are adjusted.Automatic Operation
The system automatically controls the fan
speed, air delivery, air conditioning, and
recirculation in order to heat or cool the
vehicle to the desired temperature.
When AUTO is lit, all four functions operate
automatically. Each function can also be
manually set and the selected setting is
displayed. Functions not manually set will
continue to be automatically controlled,
even if the AUTO indicator is not lit.
For automatic operation:
1. Press AUTO.
2. Set the temperature. Allow the system time to stabilize. Adjust the temperature
as needed for best comfort.
To improve fuel efficiency and to cool the
vehicle faster, recirculation may be
automatically selected in warm weather.
The recirculation light will not come on
when automatically controlled. See@
under “Manual Operation” for more details.
Manual Operation
9:Turn clockwise or counterclockwise to
increase or decrease the fan speed. Press the
knob to turn the fan off. When off is selected, a small amount of air may still
come out of the outlets depending on
vehicle speed. If any buttons are pressed or
knobs are turned, the climate control system
will turn on and operate at the current
setting.
Press AUTO to return to automatic
operation.
Driver and Passenger Temperature Control :
The temperature can be adjusted separately
for the driver and passenger.
Turn the knob clockwise or counterclockwise
to increase or decrease the driver or
passenger temperature setting. The driver
side or passenger side temperature display
shows the temperature setting increasing or
decreasing.
SYNC :
Press to link the passenger
temperature setting to the driver setting.
The SYNC indicator light will turn on. When
the passenger setting is adjusted, the SYNC
indicator light will turn off.
Air Delivery Mode Control : Press
z,Y,
or
[to change the direction of the
airflow. Any combination of the three
controls can be selected. An indicator light
comes on in the selected mode button.

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Driving and Operating 211
Driving and Operating
Driving Information
Driving for Better Fuel Economy . . . . . . . 212
Distracted Driving . . . . . . . . . . . . . . . . . . . . . . 212
Defensive Driving . . . . . . . . . . . . . . . . . . . . . . 213
Impaired Driving . . . . . . . . . . . . . . . . . . . . . . . 213
Control of a Vehicle . . . . . . . . . . . . . . . . . . . . 213
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 214
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . . 215
Off-Road Driving . . . . . . . . . . . . . . . . . . . . . . . 215
Driving on Wet Roads . . . . . . . . . . . . . . . . . 219
Hill and Mountain Roads . . . . . . . . . . . . . . 219
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . 220
If the Vehicle Is Stuck . . . . . . . . . . . . . . . . . . 221
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . 222
Truck-Camper Loading Information . . . . 226
Starting and Operating
New Vehicle Break-In . . . . . . . . . . . . . . . . . . 228
Ignition Positions (Key Access) . . . . . . . . 229
Ignition Positions (Keyless Access) . . . . . 230
Starting the Engine . . . . . . . . . . . . . . . . . . . . 232
Stop/Start System . . . . . . . . . . . . . . . . . . . . . 233
Engine Heater . . . . . . . . . . . . . . . . . . . . . . . . . 234
Retained Accessory Power (RAP) . . . . . . . 236
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . 236
Shifting out of Park . . . . . . . . . . . . . . . . . . . 237Parking over Things That Burn . . . . . . . . . 237
Active Fuel Management . . . . . . . . . . . . . . 237
Extended Parking . . . . . . . . . . . . . . . . . . . . . . 238
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . 238
Running the Vehicle While Parked . . . . . 238
Automatic Transmission
Automatic Transmission . . . . . . . . . . . . . . . 239
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . 241
Tow/Haul Mode . . . . . . . . . . . . . . . . . . . . . . . 242
Drive Systems
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 242
Brakes
Electric Brake Boost . . . . . . . . . . . . . . . . . . . 246
Antilock Brake System (ABS) . . . . . . . . . . 246
Electric Parking Brake . . . . . . . . . . . . . . . . . . 247
Brake Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Hill Start Assist (HSA) . . . . . . . . . . . . . . . . . 248
Ride Control Systems
Traction Control/Electronic Stability
Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Hill Descent Control (HDC) . . . . . . . . . . . . 250
Driver Mode Control . . . . . . . . . . . . . . . . . . . 251
Limited-Slip Differential . . . . . . . . . . . . . . . . 254
Locking Rear Axle . . . . . . . . . . . . . . . . . . . . . 254
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . 254
Adaptive Cruise Control (Camera) . . . . . . 256
Driver Assistance Systems
Driver Assistance Systems . . . . . . . . . . . . . 265
Assistance Systems for Parking or Backing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Assistance Systems for Driving . . . . . . . . 274
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
Automatic Emergency Braking (AEB) . . . 277
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Side Blind Zone Alert (SBZA) . . . . . . . . . . 280
Lane Change Alert (LCA) . . . . . . . . . . . . . . . 280
Lane Keep Assist (LKA) . . . . . . . . . . . . . . . . . 281
Fuel
Top Tier Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Recommended Fuel (Except 6.2L V8 Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Recommended Fuel (6.2L V8 Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . 284
Fuels in Foreign Countries . . . . . . . . . . . . . 284
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . 284
E85 or FlexFuel . . . . . . . . . . . . . . . . . . . . . . . . 284
Filling the Tank (Pickup Model) . . . . . . . . 285
Filling the Tank (Chassis Cab Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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212 Driving and Operating
Filling a Portable Fuel Container . . . . . . . 288
Trailer Towing
General Towing Information . . . . . . . . . . 288
Driving Characteristics andTowing Tips . . . . . . . . . . . . . . . . . . . . . . . . . 288
Trailer Towing . . . . . . . . . . . . . . . . . . . . . . . . . 293
Towing Equipment . . . . . . . . . . . . . . . . . . . . 296
Trailer Sway Control (TSC) . . . . . . . . . . . . 306
Trailering App . . . . . . . . . . . . . . . . . . . . . . . . . 307
Conversions and Add-Ons
Add-On Electrical Equipment . . . . . . . . . . . 318
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
Pickup Conversion to Chassis Cab . . . . . 320
Driving Information
Driving for Better Fuel Economy
Driving habits can affect fuel mileage. Here
are some driving tips to get the best fuel
economy possible:
.Set the climate controls to the desired
temperature after the engine is started,
or turn them off when not required.
.Avoid fast starts and accelerate smoothly.
.Brake gradually and avoid abrupt stops.
.Avoid idling the engine for long periods
of time.
.When road and weather conditions are
appropriate, use cruise control.
.Always follow posted speed limits or
drive more slowly when conditions
require.
.Keep vehicle tires properly inflated.
.Combine several trips into a single trip.
.Replace the vehicle's tires with the same
TPC Spec number molded into the tire's
sidewall near the size.
.Follow recommended scheduled
maintenance.
Distracted Driving
Distraction comes in many forms and can
take your focus from the task of driving.
Exercise good judgment and do not let other
activities divert your attention away from
the road. Many local governments have
enacted laws regarding driver distraction.
Become familiar with the local laws in
your area.
To avoid distracted driving, keep your eyes
on the road, keep your hands on the
steering wheel, and focus your attention on
driving.
.Do not use a phone in demanding driving
situations. Use a hands-free method to
place or receive necessary phone calls.
.Watch the road. Do not read, take notes,
or look up information on phones or
other electronic devices.
.Designate a front seat passenger to
handle potential distractions.
.Become familiar with vehicle features
before driving, such as programming
favorite radio stations and adjusting
climate control and seat settings. Program
all trip information into any navigation
device prior to driving.

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Driving and Operating 213
.Wait until the vehicle is parked to
retrieve items that have fallen to the
floor.
.Stop or park the vehicle to tend to
children.
.Keep pets in an appropriate carrier or
restraint.
.Avoid stressful conversations while
driving, whether with a passenger or on a
cell phone.
{Warning
Taking your eyes off the road too long or
too often could cause a crash resulting in
injury or death. Focus your attention on
driving.
Refer to the infotainment section for more
information on using that system and the
navigation system, if equipped, including
pairing and using a cell phone.
Defensive Driving
Defensive driving means “always expect the
unexpected.” The first step in driving
defensively is to wear the seat belt. See
Seat Belts 054.
.Assume that other road users
(pedestrians, bicyclists, and other drivers)
are going to be careless and make
mistakes. Anticipate what they may do
and be ready.
.Allow enough following distance between
you and the driver in front of you.
.Focus on the task of driving.
Impaired Driving
Death and injury associated with impaired
driving is a global tragedy.
{Warning
Drinking alcohol or taking drugs and then
driving is very dangerous. Your reflexes,
perceptions, attentiveness, and judgment
can be affected by even a small amount
of alcohol or drugs. You can have a
serious —or even fatal —collision if you
drive after drinking or taking drugs.
Do not drive while under the influence of
alcohol or drugs, or ride with a driver
who has been drinking or is impaired by
drugs. Find alternate transportation
home; or if you are with a group,
designate a driver who will remain sober.
Control of a Vehicle
Braking, steering, and accelerating are
important factors in helping to control a
vehicle while driving.
Braking
Braking action involves perception time and
reaction time. Deciding to push the brake
pedal is perception time. Actually doing it is
reaction time.
Average driver reaction time is about
three-quarters of a second. In that time, a
vehicle moving at 100 km/h (60 mph) travels
20 m (66 ft), which could be a lot of
distance in an emergency.
Helpful braking tips to keep in mind include:
.Keep enough distance between you and
the vehicle in front of you.
.Avoid needless heavy braking.
.Keep pace with traffic.
If the engine ever stops or a brake fault
occurs, the brakes may lose power assist.
More effort will be required to stop the
vehicle. It may take longer to stop.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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216 Driving and Operating
Caution
Operating the vehicle for extended
periods without the front fascia lower air
dam installed can cause improper airflow
to the engine. Reattach the front fascia
air dam after off-road driving.
Loading the Vehicle for Off-Road Driving
{Warning
.Unsecured cargo on the load floor can
be tossed about when driving over
rough terrain. You or your passengers
can be struck by flying objects. Secure
the cargo properly.
.Keep cargo in the cargo area as far
forward and as low as possible. The
heaviest things should be on the floor,
forward of the rear axle.
.Heavy loads on the roof raise the
vehicle's center of gravity, making it
more likely to roll over. You can be
seriously or fatally injured if the
vehicle rolls over. Put heavy loads
inside the cargo area, not on the roof.For more information about loading the
vehicle, see
Vehicle Load Limits 0222 and
Tires 0360.
Environmental Concerns
.Always use established trails, roads, and
areas that have been set aside for public
off-road recreational driving and obey all
posted regulations.
.Do not damage shrubs, flowers, trees,
or grasses or disturb wildlife.
.Do not park over things that burn. See
Parking over Things That Burn 0237.
Driving on Hills
Driving safely on hills requires good
judgment and an understanding of what the
vehicle can and cannot do.
{Warning
Many hills are simply too steep for any
vehicle. Driving up hills can cause the
vehicle to stall. Driving down hills can
cause loss of control. Driving across hills
can cause a rollover. You could be injured
or killed. Do not drive on steep hills. Before driving on a hill, assess the
steepness, traction, and obstructions. If the
terrain ahead cannot be seen, get out of the
vehicle and walk the hill before driving
further.
When driving on hills:
.Use a low gear and keep a firm grip on
the steering wheel.
.Maintain a slow speed.
.When possible, drive straight up or down
the hill.
.Slow down when approaching the top of
the hill.
.Use headlamps even during the day to
make the vehicle more visible.
{Warning
Driving to the top of a hill at high speed
can cause a crash. There could be a
drop-off, embankment, cliff, or even
another vehicle. You could be seriously
injured or killed. As you near the top of a
hill, slow down and stay alert.
.Never go downhill forward or backward
with either the transmission or transfer
case in N (Neutral). The brakes could
overheat and you could lose control.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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222 Driving and Operating
Caution
Never use recovery hooks to tow the
vehicle. The vehicle could be damaged,
and the repairs would not be covered by
the vehicle warranty.
If equipped, there are recovery hooks at the
front of the vehicle. Use them if the vehicle
is stuck off-road and needs to be pulled
some place to continue driving.
Vehicle Load Limits
It is very important to know how much
weight the vehicle can carry. This
weight is called the vehicle capacity
weight and includes the weight of all
occupants, cargo, and all
nonfactory-installed options. Two labels
on the vehicle may show how much
weight it was designed to carry: the
Tire and Loading Information label and
the Certification/Tire label.
{Warning
Do not load the vehicle any heavier
than the Gross Vehicle Weight Rating
(GVWR), or either the maximum
front or rear Gross Axle Weight
Rating (GAWR). This can cause
systems to break and change the
way the vehicle handles. This could
cause loss of control and a crash.
Overloading can also reduce stopping
performance, damage the tires, and
shorten the life of the vehicle.
Tire and Loading Information Label
Label Example
A vehicle-specific Tire and Loading
Information label is attached to the
center pillar (B-pillar). The Tire and
Loading Information label shows the
number of occupant seating
positions (1), and the maximum vehicle
capacity weight (2) in kilograms and
pounds.
The Tire and Loading Information label
also shows the size of the original
equipment tires (3) and the
recommended cold tire inflation

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Driving and Operating 225
the actual loads on the front and rear
axles, weigh the vehicle at a weigh
station. Your dealer can help with this.
Be sure to spread the load equally on
both sides of the centerline.
The Certification/Tire label also contains
important information about the Front
Axle Reserve Capacity. SeeAdding a
Snow Plow or Similar Equipment 0318.
{Warning
In the case of a sudden stop or
collision, things carried in the bed of
your truck could shift forward and
come into the passenger area,
injuring you and others. If you put
things in the bed of your truck, you
should make sure they are properly
secured.
Caution
Overloading the vehicle may cause
damage. Repairs would not be covered by
the vehicle warranty. Do not overload the
vehicle.
Using heavier suspension components
to get added durability might not
change the weight ratings. Ask your
dealer to help load the vehicle the
right way.
{Warning
Things you put inside the vehicle can
strike and injure people in a sudden
stop or turn, or in a crash.
.Put things in the cargo area of the
vehicle. Try to spread the weight
evenly.
.Never stack heavier things, like
suitcases, inside the vehicle so
that some of them are above the
tops of the seats.
.Do not leave an unsecured child
restraint in the vehicle.
.When you carry something inside
the vehicle, secure it whenever
you can.
.Do not leave a seat folded down
unless you need to. There is also important loading
information for off-road driving in this
manual. See
“Loading the Vehicle for
Off-Road Driving“ underOff-Road
Driving 0215.
Two-Tiered Loading
Depending on the model of the pickup,
an upper load platform can be created
by positioning three or four 5 cm (2 in)
by 15 cm (6 in) wooden planks across
the width of the pickup box. The planks
must be inserted in the pickup box
depressions.
When using this upper load platform,
be sure the load is securely tied down
to prevent it from shifting. The load's
center of gravity should be positioned
in a zone over the rear axle. The zone is
located in the area between the front
of each wheel well and the rear of each
wheel well. The center of gravity height
must not extend above the top of the
pickup box flareboard.