lights GMC SIERRA 2021 Owner's Guide

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 307
trailer connections or trailer brakes could
appear on the DIC. The effects of these
aftermarket devices may have on vehicle
handling or trailer brake performance is not
known.
{Warning
Use of aftermarket electronic trailer sway
control devices could result in reduced
trailer brake performance, loss of trailer
brakes, or other malfunctions, and result
in a crash. You or others could be
seriously injured or killed. Before using
one of these devices:
.Ask the device or trailer manufacturer
if the device has been thoroughly
tested for compatibility with the
make, model, and year of your vehicle
and any optional equipment installed
on your vehicle.
.Before driving, check the trailer brakes
are working properly, if equipped.
Drive the vehicle with the trailer
attached on a level road surface that
is free of traffic at about 32-40 km/h
(20-25 mph) and fully apply the(Continued)
Warning (Continued)
manual trailer brake apply lever. Also,
check the trailer brake lamps and
other lamps are functioning correctly.
.If the trailer brakes are not operating
properly at any time, or if a DIC
message indicates problems with the
trailer connections or trailer brakes,
carefully pull the vehicle over to the
side of the road when traffic
conditions allow.
Trailer Tires
Special Trailer (ST) tires differ from vehicle
tires. Trailer tires are designed with stiff
sidewalls to help prevent sway and to
support heavy loads. These features can
make it difficult to determine if the trailer
tire pressures are low only based on a visual
inspection.
Always check all trailer tire pressures before
each trip when the tires are cool. Low trailer
tire pressure is a leading cause of trailer tire
blow-outs. If the vehicle is equipped with a trailer tire
pressure monitoring system, see the trailer
tire pressure monitoring system description
and the trailering app.
Trailer tires deteriorate over time. The trailer
tire sidewall will show the week and year
the tire was manufactured. Many trailer tire
manufacturers recommend replacing tires
more than six years old.
Overloading is another leading cause of
trailer tire blow-outs. Never load your trailer
with more weight than the tires are
designed to support. The load rating is
located on the trailer tire sidewall.
Always know the maximum speed rating for
the trailer tires before driving. This may be
significantly lower than the vehicle tire
speed rating. The speed rating may be on
the trailer tire sidewall. If the speed rating is
not shown, the default trailer tire speed
rating is 105 km/h (65 mph).
Trailering App
Trailer Lights App
If equipped, the Trailer Lights App is on the
Home Page of the infotainment display.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
308 Driving and Operating
Touch Start to cycle the trailer lamps on and
off to determine if they are working. The
test follows this sequence:1. The running lights turn on first and remain on throughout the sequence.
2. The brake lights turn on for about two seconds.
3. The left turn signal light flashes three times.
4. The right turn signal light flashes three times.
5. The reverse lights turn on for about two seconds.
6. Steps 2–5 repeat for approximately one minute and 45 seconds, or until the
test deactivates.
Touch Stop to stop the test. The test will
automatically end after one minute and
45 seconds.
The sequence also deactivates when any of
the following occur:
.The ignition is turned off.
.The transmission is shifted out of P (Park).
.The brake pedal is pressed.
.The turn signal is activated.
.The hazard warning lights are activated.
Trailering App
If equipped, the Trailering App is on the
Home Page of the infotainment display.
If equipped this feature allows profiles for
connected trailers to be created to view
status, to store and track trailer usage
information, and to set up towing assistance
features.
The Trailering App Preview will appear when
the Trailering App is opened for the first
time from the Home Page. Touch GET
STARTED in the Trailering App to go into
the app.
When a trailer is electrically connected and
a trailer profile has not been created, there
will be an option to create a profile, use a
guest profile, or select Accessory/No trailer.
After the pop-up is displayed three times,
Don’t Remind Me will display and touching
that will turn off the trailer detection
pop-up. To turn the Trailer Detection Alert
on, select ON in the Settings tab.
When a trailer is electrically connected and
after a Trailer Profile has been created, the
trailer detection pop-up will appear with a
list of all of the custom Trailer Profiles made
on the vehicle. To load an existing Trailer
Profile, select one of the Trailer Profiles listed, or load the Guest Trailer Profile by
selecting GUEST TRAILER. Touching
Accessory/No trailer will select Accessory/No
trailer as the active Trailer Profile and will
dismiss the pop- up. Shifting the vehicle
from P (Park) will select Guest Trailer as the
active Trailer Profile and will dismiss the
pop-up.
Create a Trailer Profile
1. Touch Create Profile on the trailer detection pop-up or touch + Add Trailer
Profile in the Trailering App.
2. Create a name for the trailer.
3. Select the trailer type.
4. Select Save Profile.
A pop-up will indicate the setup is complete.
Touch DONE to complete the process or
touch TRAILER FEATURE SETUP to set up the
Tow/Haul Mode reminder, Trailer Tire
Pressure Monitoring System, if equipped,
maintenance reminders, or towing
assistance, if equipped.
Import a Trailer Profile
A trailer profile saved to an OnStar account
can be imported to the vehicle. 1. Touch + Add Trailer Profile in the Trailering App

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 309
2. Touch Import Profile on the pop-up.
3. Select a trailer profile from the list.
4. Touch IMPORT.
A pop-up will indicate the import was
successful. Touch OK to return to the trailer
list and select the trailer profile. The Tow/
Haul Mode reminder, Brake Gain Setting and
Trailer Tire Pressure sensor learning,
if equipped, do not import.
Trailer Feature Setup
Tow/Haul Mode Reminder
To turn the Tow/Haul Mode Reminder
setting on, touch Yes. To turn it off,
touch No.
Trailer Tire Pressure Setup
If the Trailer Tire Pressure Monitoring
System (TTPMS) is detected, touch the Tire
Pressure Monitoring icon to set up tire
pressure monitoring. Touch Yes to set up
the sensors or touch No to return to the
previous screen.
The trailer tire pressure sensors can transmit
up to 7 m (23 feet) from the hitch receiver of
the vehicle. A trailer must be electrically connected to
the vehicle before starting the
sensor-to-vehicle learn process.
After selecting Start from the Learn Sensors
screen, use the Tool Method or the Manual
Method (described below) to learn each tire
sensor, during which the current tire number
will be highlighted.
Each sensor has a minimum of two minutes
to learn, shown by a timer. After a sensor is
learned, a checkmark appears next to the
tire, the vehicle horn will sound, the
vehicle’s brake lamps will flash, and all
working trailer lamps will flash. It then
moves to the next sensor.
To cancel the process touch Stop.
The recommended tire pressure must be
entered for the trailer tires. This allows the
vehicle to alert when the tire pressure is
high or low.
TTPMS must learn the location of the
installed tire sensors to show correct air
pressure and temperature for each tire. To
set up, use one of the following options or
see a tire or trailer dealer for service. The
learning process must be repeated when thetrailer tires are rotated or replaced. See
“Editing a Trailer Profile”
later in this section
for tire pressure sensor relearn information.
Tool Method: A TTPMS activation tool can
be purchased separately to learn the sensor
locations.
Manual Method: Without the tool, the air
pressure can be increased or decreased in
each tire for 10 seconds. Do not exceed the
maximum inflation pressure found on the
tire sidewalls. Make sure to re-adjust tire
pressure to the recommended level when
the process is complete.
Sensor Learning Steps
To complete the sensor-to-vehicle learn
process:
1. Touch Start on the Learn Sensors screen. The horn chirps twice and the Learning
Active screen appears on the
infotainment display.
2. Start with the driver side front trailer tire.
3. Activate the tool near the valve stem or adjust the air pressure of this tire until
the horn chirps and all working vehicle
and trailer lights flash.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
312 Driving and Operating
trailer is connected. When a trailer is
connected and the ignition is off, the
Trailering App System will periodically pulse
the lighting circuits of the trailer to verify it
is still connected. The trailer lights may
periodically flash as a result of this trailer
connection detection. These flashes may be
more visible in dark ambient light
environments. The flashing or flickering
lights are a normal condition and the
Trailering App System has built-in
protections to prevent the battery from
draining. When Theft Alert is also enabled
the frequency and pattern of this flashing
will change.
Connection Problem
If any of the trailer connections are lost, a
message about the connection issue will
appear on the Driver Information Center
(DIC). The infotainment display will also
show the connection issue in the Connection
Status view.
If a trailer connection is not detected, the
Trailering App will not display the
Connection Status screen.Connection Trailer Lighting Faults Detected
The Trailering App System monitors for
electrical faults on the trailer lights.
A message about the lighting issue will
appear on the DIC. The infotainment display
will also show the lighting issue in the
Connection Status view. Repair your trailer
lights if needed. A trailer lighting issue is
not covered by your GM warranty.
Diagnose View
Touch Diagnose to see more information
about the connection problem.
This view will display the names of the
trailer connector pins, a graphic of the trailer
connector, and a graphic of the back of the
trailer.
Any connector pin that failed will be amber
color, and the location of the corresponding
connection will be highlighted on the
graphic of the back of the trailer.
The Running Lights connection may not
detect partial outages. Activate the light test
to check all trailer lamps. See
“Light Test”
following. Light Test
Touch Start Light Test to cycle the trailer
lights on and off to determine if they are
working. The test follows this sequence:
1. The running lights turn on first and remain on throughout the sequence.
2. The brake lights turn on for about two seconds.
3. The left turn signal light flashes three times.
4. The right turn signal light flashes three times.
5. The reverse lights turn on for about two seconds.
6. Steps 2–5 repeat for approximately one minute and 45 seconds, or until the
test deactivates.
Touch Stop to stop the test. The test will
automatically end after one minute and
45 seconds.
The sequence also deactivates when any of
the following occur:
.The ignition is turned off.
.The transmission is shifted out of P (Park).
.The brake pedal is pressed.
.The turn signal is activated.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 313
.The hazard warning lights are activated.
Tires
1. Trailer Tire Pressure/Temperature
Tire Pressure and Temperature
If the TTPMS sensor-to-vehicle learn process
was completed, the status view will display
the current tire pressure and temperature of
the trailer tires related to the active Trailer
Profile. If a tire’s pressure is low or high, the
color of the pressure value will be amber.
If a sensor malfunctions, the values are
dashed lines. If the screen displays“Service
Tire Pressure Monitoring System”, the
vehicle needs to be taken to a dealer for
service.
Maintenance
1. List of Maintenance Reminders
2. Add a New Maintenance Reminder
The Maintenance Status view displays
reminders. Touch a reminder to edit.
Touch + New Maintenance Reminder to go
to the Select New Reminder view.
The progress bar turns yellow when the
maintenance item reaches 90% complete.
The progress bar turns red when the
maintenance item reaches 100% complete.
Maintenance Notifications
.Touch Service Complete to reset the
maintenance reminder.
.Touch Remind Me Later to delay the
reminder.
.Touch X next to Upcoming Alerts (90%)
to dismiss the alert. It will not appear
again.
.Touch X next to Maintenance Due (100%)
to delay the alert to the next ignition
cycle.
Always follow all of the maintenance
instructions that came with your trailer.
Cameras
Guest Trailer Status View
Touch the Guest Trailer Profile for the status
views.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
416 Service and Maintenance
.Trained dealer technicians have the
diagnostic equipment to test the battery
and ensure that the connections and
cables are corrosion-free.
Belts
.Belts may need replacing if they squeak
or show signs of cracking or splitting.
.Trained dealer technicians have access to
tools and equipment to inspect the belts
and recommend adjustment or
replacement when necessary.
Brakes
Brakes stop the vehicle and are crucial to
safe driving.
.Signs of brake wear may include chirping,
grinding, or squealing noises, or difficulty
stopping.
.Trained dealer technicians have access to
tools and equipment to inspect the brakes
and recommend quality parts engineered
for the vehicle.
Fluids
Proper fluid levels and approved fluids
protect the vehicle’s systems and
components. See Recommended Fluids and
Lubricants 0418 for GM approved fluids.
.Engine oil and windshield washer fluid
levels should be checked at every fuel fill.
.Instrument cluster lights may come on to
indicate that fluids may be low and need
to be filled.
Hoses
Hoses transport fluids and should be
regularly inspected to ensure that there are
no cracks or leaks. With a multi-point
inspection, your dealer can inspect the hoses
and advise if replacement is needed.
Lamps
Properly working headlamps, taillamps, and
brake lamps are important to see and be
seen on the road.
.Signs that the headlamps need attention
include dimming, failure to light, cracking,
or damage. The brake lamps need to be
checked periodically to ensure that they
light when braking.
.With a multi-point inspection, your dealer
can check the lamps and note any
concerns.
Shocks and Struts
Shocks and struts help aid in control for a
smoother ride.
.Signs of wear may include steering wheel
vibration, bounce/sway while braking,
longer stopping distance, or uneven
tire wear.
.As part of the multi-point inspection,
trained dealer technicians can visually
inspect the shocks and struts for signs of
leaking, blown seals, or damage, and can
advise when service is needed.
Tires
Tires need to be properly inflated, rotated,
and balanced. Maintaining the tires can save
money and fuel, and can reduce the risk of
tire failure.
.Signs that the tires need to be replaced
include three or more visible treadwear
indicators; cord or fabric showing through
the rubber; cracks or cuts in the tread or
sidewall; or a bulge or split in the tire.
.Trained dealer technicians can inspect and
recommend the right tires. Your dealer
can also provide tire/wheel balancing
services to ensure smooth vehicle
operation at all speeds. Your dealer sells
and services name brand tires.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
452 Index
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Filter, Engine Air Cleaner . . . . . . . . . . . . . . . . . . . . . 334
Fixed Mast Antenna . . . . . . . . . . . . . . . . . . . . . .158
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Flashers, Hazard Warning . . . . . . . . . . . . . . . . .142
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
FlexFuel E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Floor Console Storage . . . . . . . . . . . . . . . . . . . . . 97
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
Fluid Automatic Transmission . . . . . . . . . . . . . . . 333
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
Four-Wheel Drive Transfer Case . . . . . . . . 242
Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Fog Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Forward Collision Alert (FCA) System . . . . 275
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . 242, 346
Four-Wheel-Drive Light . . . . . . . . . . . . . . . . . . . . 118
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 Front Fog Lamp
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Heated and Ventilated . . . . . . . . . . . . . . . . . . 52
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Economy, Driving for Better . . . . . . . . . . . 212
Filling a Portable Fuel Container . . . . . . . 288
Filling the Tank . . . . . . . . . . . . . . . . . . . 285, 287
Foreign Countries . . . . . . . . . . . . . . . . . . . . . . 284
Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Low Fuel Warning Light . . . . . . . . . . . . . . . 122
Management, Active . . . . . . . . . . . . . . . . . . . 237
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . 284
Recommended . . . . . . . . . . . . . . . . . . . . 283, 284
Top Tier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . . . . 390
Fuses Engine Compartment Fuse Block . . . . . . . 353
Fuses and Circuit Breakers . . . . . . . . . . . . . 353
Instrument Panel Fuse Block . . . . . . 357, 358
G
Garage Door Opener . . . . . . . . . . . . . . . . . . . . . 136Programming . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
Gauges Engine Coolant Temperature . . . . . . . . . . . . 112
Engine Oil Pressure . . . . . . . . . . . . . . . . . . . . . 111
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . . 110
Voltmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Warning Lights and Indicators . . . . . . . . . 106
General Information Service and Maintenance . . . . . . . . . . . . . . 408
Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Glass Replacement . . . . . . . . . . . . . . . . . . . . . . . 348
Global Positioning System (GPS) . . . . . . . . . . 173
Glove Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
GM Mobility Reimbursement
Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .431
Guidance
Problems with the Route . . . . . . . . . . . . . . 174

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
454 Index
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
LightingEntry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Illumination Control . . . . . . . . . . . . . . . . . . . 145
LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Lights Airbag Readiness . . . . . . . . . . . . . . . . . . . . . . . 114
Antilock Brake System (ABS)Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Brake System Warning . . . . . . . . . . . . . . . . . 117
Charging System . . . . . . . . . . . . . . . . . . . . . . . 115
Check Engine (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . 123
Door Ajar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Driver Mode Control . . . . . . . . . . . . . . . . . . . . 121
Electric Parking Brake . . . . . . . . . . . . . . . . . . . 117
Electronic Stability Control (ESC), Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Engine Coolant Temperature Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Engine Oil Pressure . . . . . . . . . . . . . . . . . . . . 122
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Four-Wheel-Drive . . . . . . . . . . . . . . . . . . . . . . . 118
Front Fog Lamp . . . . . . . . . . . . . . . . . . . . . . . . 123
High-Beam On . . . . . . . . . . . . . . . . . . . . . . . . . 123 Lights (cont'd)
High/Low Beam Changer . . . . . . . . . . . . . . . 141
Hill Descent Control . . . . . . . . . . . . . . . . . . . . 119
Lane Keep Assist . . . . . . . . . . . . . . . . . . . . . . . . 119
Low Fuel Warning . . . . . . . . . . . . . . . . . . . . . 122
Seat Belt Reminders . . . . . . . . . . . . . . . . . . . . 113
Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Service Electric Parking Brake . . . . . . . . . . . 118
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Tow/Haul Mode . . . . . . . . . . . . . . . . . . . . . . . . 119
Traction Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Limited-Slip Differential . . . . . . . . . . . . . . . . . . 254
Lock
Steering Column . . . . . . . . . . . . . . . . . . . . . . . . 32
Locking Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . 254
Locks Automatic Door . . . . . . . . . . . . . . . . . . . . . . . . . 22
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 22
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Lockout Protection . . . . . . . . . . . . . . . . . . . . . . 22
Power Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Low Fuel Warning Light . . . . . . . . . . . . . . . . . . 122
Lower Anchors and Tethers for Children (LATCH System) . . . . . . . . . . . . . . . . .77
Lumbar Adjustment . . . . . . . . . . . . . . . . . . . . . . . 48 Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
Maintenance and Care Additional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Maintenance Schedule . . . . . . . . . . . . . . . . . . . 409 Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
Transfer Case . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Malfunction Indicator Lamp . . . . . . . . . . . . . . . 115
Manual Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . .241
Manual Windows . . . . . . . . . . . . . . . . . . . . . . . . . .41
Map Data Updates . . . . . . . . . . . . . . . . . . . . . . . . 175
Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Media
Avoiding Untrusted Devices . . . . . . . . . . . . 158
Memory Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Messages Engine Power . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Vehicle Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Mirror Rear Camera . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Mirrors Automatic Dimming . . . . . . . . . . . . . . . . . . . . 37
Automatic Dimming Rearview . . . . . . . . . . 38
Blind Spot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
Index 459
Turn and Lane-Change Signals . . . . . . . . . . . .143
Turn SignalBulb Replacement . . . . . . . . . . . . . . . . . . . . . . 351
U
Underseat Storage . . . . . . . . . . . . . . . . . . . . . . . . 96
Uniform Tire Quality Grading . . . . . . . . . . . . 377
Universal Remote System . . . . . . . . . . . . . . . . 136Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Updates Map Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
USB Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158
Using the Navigation System . . . . . . . . . . . . 163
Using the System . . . . . . . . . . . . . . . . . . . . . . . . . 152
Using This Manual . . . . . . . . . . . . . . . . . . . . . . . . . .2
V
Vehicle Alarm System . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Canadian Owners . . . . . . . . . . . . . . . . . . . . . . . . 2
Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Identification Number (VIN) . . . . . . . . . . . . 423
Load Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Personalization . . . . . . . . . . . . . . . . . . . . . . . . . 131
Remote Start . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Vehicle (cont'd)
Speed Messages . . . . . . . . . . . . . . . . . . . . . . . . 131
Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394
Vehicle Ahead Indicator . . . . . . . . . . . . . . . . . . . 119
Vehicle Care Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
Vehicle Data Recording and Privacy . . . . . . 437
Vehicle Positioning . . . . . . . . . . . . . . . . . . . . . . .174
Vehicle Security
Steering Column Lock . . . . . . . . . . . . . . . . . . . 32
Ventilation, Air . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Voice Recognition . . . . . . . . . . . . . . . . . . . . . . . . . 175
Voltmeter Gauge . . . . . . . . . . . . . . . . . . . . . . . . . 113
W
Warning Brake System Light . . . . . . . . . . . . . . . . . . . . . 117
Caution and Danger . . . . . . . . . . . . . . . . . . . . . 2
Warning Lights, Gauges, and Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Warnings
Hazard Flashers . . . . . . . . . . . . . . . . . . . . . . . . 142
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Wheels Alignment and Tire Balance . . . . . . . . . . . . 378
Different Size . . . . . . . . . . . . . . . . . . . . . . . . . . 377
Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 378 When It Is Time for New Tires . . . . . . . . . . . 375
Where to Put the Restraint . . . . . . . . . . . . . . . 76
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Windshield
Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Wiper/Washer . . . . . . . . . . . . . . . . . . . . . . . . . 101
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
Wiper Blade Replacement . . . . . . . . . . . . . . . . 348
Wireless Charging . . . . . . . . . . . . . . . . . . . . . . . 103