2021 GMC SIERRA stop start

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 397
Keyless Access, keep the RKE transmitter
outside of the vehicle and manually lock
the doors. Access the vehicle by using
the key in the door lock. SeeDoor Locks
0 21.
Disconnecting the Towed Vehicle
Before disconnecting from the tow vehicle: 1. Park on a level surface. Secure the vehicle with wheel blocks.
2. Re-connect the negative (–) battery. See Battery - North America 0343.
3. Turn on the ignition with the engine off. For vehicles with a key, turn the ignition
to ON/RUN with the engine off. If the
vehicle is equipped with Keyless Access,
with your foot off the brake pedal, press
and hold ENGINE START/STOP for
five seconds until the green light comes
on in the button. See Ignition Positions
(Keyless Access) 0230 or
Ignition Positions (Key Access) 0229.
4. Set the parking brake. See Electric
Parking Brake 0247.
5. Disconnect from the tow vehicle.
6. Shift the transmission to N (Neutral). 7. Shift the transfer case to 2m(Two-Wheel
Drive High). When the shift to 2
m
(Two-Wheel Drive High) is complete, the
light in the instrument cluster will stop
flashing and stay lit. See
Four-Wheel-Drive Light 0118.
8. Start the engine. Check that the vehicle is in 2
m(Two-Wheel Drive High) by
starting the engine and shifting the
transmission to D (Drive) and then to
R (Reverse). There should be movement
of the vehicle while shifting.
9. Shift the transmission to P (Park) and turn off the ignition.
10. Release the parking brake and remove the wheel blocks.
11. Reset any lost presets. The outside temperature display will
default to 0 °C (32 °F) but will reset with
normal usage.
Dolly Towing

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
446 Connected Services
PressQ, then ask the Advisor to download
directions to the vehicle’s navigation system,
if equipped. After the call ends, the
navigation screen will provide prompts to
begin driving directions. Routes that are sent
to the navigation screen can only be
canceled through the navigation system.
See www.onstar.com (U.S.) or www.onstar.ca
(Canada).
Connections
The following services help with staying
connected.
For coverage maps, see www.onstar.com
(U.S.) or www.onstar.ca (Canada).
Ensuring Security
.Change the default passwords for the
Wi-Fi hotspot and myGMC mobile
application. Make these passwords
different from each other and use a
combination of letters and numbers to
increase the security.
.Change the default name of the SSID
(Service Set Identifier). This is your
network’s name that is visible to other
wireless devices. Choose a unique name
and avoid family names or vehicle
descriptions. Wi-Fi Hotspot (If Equipped)
The vehicle may have a built-in Wi-Fi
hotspot that provides access to the Internet
and web content at 4G LTE speed. Up to
seven mobile devices can be connected.
A data plan is required. Use the in-vehicle
controls only when it is safe to do so.
1. To retrieve Wi-Fi hotspot information, press
=to open the OnStar app on the
infotainment display, then select Wi-Fi
Hotspot. On some vehicles, touch Wi-Fi
or Wi-Fi Settings on the screen.
2. The Wi-Fi settings will display the Wi-Fi hotspot name (SSID), password, and on
some vehicles, the connection type (no
Internet connection, 3G, 4G, 4G LTE), and
signal quality (poor, good, excellent). The
LTE icon shows connection to Wi-Fi. It is
possible that the icon may not illuminate
even though the vehicle has an active
connection.
3. To change the SSID or password, press
Qor call 1-888-4ONSTAR to connect
with an Advisor. On some vehicles, the
SSID and password can be changed in
the Wi-Fi Hotspot menu. After initial set-up, your vehicle’s Wi-Fi
hotspot will connect automatically to your
mobile devices. Manage data usage by
turning Wi-Fi on or off on your mobile
device, using the myGMC mobile app, or by
contacting an OnStar Advisor. On some
vehicles, Wi-Fi can also be managed from
the Wi-Fi Hotspot menu.
MyGMC Mobile App (If Available)
Download the myGMC mobile app to
compatible Apple and Android smartphones.
GMC users can access the following services
from a smartphone:
.Remotely start/stop the vehicle,
if factory-equipped.
.Lock/unlock doors, if equipped with
automatic locks.
.Activate the horn and lamps.
.Check the vehicle’s fuel level, oil life,
or tire pressure, if factory-equipped with
the Tire Pressure Monitor System.
.Send destinations to the vehicle.
.Locate the vehicle on a map (U.S.
market only).
.Turn the vehicle's Wi-Fi hotspot on/off,
manage settings, and monitor data
consumption, if equipped.
.Locate a dealer and schedule service.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
Index 449
Assistance Program, Roadside . . . . . . . . . . . . .431
Assistance Systems for Driving . . . . . . . . . . 274
Assistance Systems for Parking andBacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Audio Bluetooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Auto Stop
Stop/Start System . . . . . . . . . . . . . . . . . . . . . 233
Automatic Dimming Mirrors . . . . . . . . . . . . . . . . . . . . . . . 37
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Emergency Braking (AEB) . . . . . . . . . . . . . . 277
Headlamp System . . . . . . . . . . . . . . . . . . . . . 142
Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Transmission Fluid . . . . . . . . . . . . . . . . . . . . . 333
Automatic Transmission
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . 241
Shift Lock Control Function Check . . . . . . 347
Auxiliary Roof Mounted Lamp . . . . . . . . . . . . . . . . . . . 144
Auxiliary Jack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Avoiding Untrusted Media Devices . . . . . . . .158
Axle, Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
Axle, Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346B
Battery
Exterior Lighting Battery Saver . . . . . . . . 147
Load Management . . . . . . . . . . . . . . . . . . . . . 146
Power Protection . . . . . . . . . . . . . . . . . . . . . . 147
Battery - North America . . . . . . . . . . . . .343, 391
Blade Replacement, Wiper . . . . . . . . . . . . . . . 348
Blind Spot Mirrors . . . . . . . . . . . . . . . . . . . . . . . . .37
Bluetooth Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 180, 181
Bluetooth Audio . . . . . . . . . . . . . . . . . . . . . . . . . 162
Brake Electric Boost . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Parking, Electric . . . . . . . . . . . . . . . . . . . . . . . . 247
System Warning Light . . . . . . . . . . . . . . . . . . 117
Brake Pad Life System . . . . . . . . . . . . . . . . . . . 342
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .341 Antilock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
Pad Life System . . . . . . . . . . . . . . . . . . . . . . . 342
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Automatic Emergency (AEB) . . . . . . . . . . . 277
Braking System
Front Pedestrian (FPB) . . . . . . . . . . . . . . . . . 278
Break-In, New Vehicle . . . . . . . . . . . . . . . . . . . . 228 Bulb Replacement
Center High-Mounted Stoplamp
(CHMSL) and Cargo Lamp . . . . . . . . . . . . 352
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 350
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . 350
Headlamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Headlamps, Front Turn Signal, Sidemarker, and Parking Lamps . . . . . . 350
License Plate Lamps . . . . . . . . . . . . . . . . . . . 352
Taillamps, Turn Signal, Stoplamps, and Back-up Lamps . . . . . . . . . . . . . . . . . . 351
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . . . 376
C
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
California Perchlorate Materials Requirements . . . 322
California Proposition 65 Warning . . . . . . . . . . . . . . . . . . .322, 343, 391, Back Cover
Canadian Vehicle Owners . . . . . . . . . . . . . . . . . . .2
Capacities and Specifications . . . . . . . . . . . . . 424
Carbon Monoxide
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . 238
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . 220
Cargo Tie-Downs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
Index 457
S
Safety Defects ReportingCanadian Government . . . . . . . . . . . . . . . . . 437
General Motors . . . . . . . . . . . . . . . . . . . . . . . . 437
U.S. Government . . . . . . . . . . . . . . . . . . . . . . . 436
Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Safety System Check . . . . . . . . . . . . . . . . . . . . . 60
Satellite Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Scheduling Appointments . . . . . . . . . . . . . . . . 433
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Extender . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
How to Wear Seat Belts Properly . . . . . . . 55
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . 57
Reminders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Replacing after a Crash . . . . . . . . . . . . . . . . . 60
Use During Pregnancy . . . . . . . . . . . . . . . . . . 59
Seats Adjustment, Front . . . . . . . . . . . . . . . . . . . . . . 46
Center Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . 45
Heated and Ventilated Front . . . . . . . . . . . . 52
Heated, Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Lumbar Adjustment, Front . . . . . . . . . . . . . . 48
Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Power Adjustment, Front . . . . . . . . . . . . . . . 47
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . 48 Seats (cont'd)
Underseat Storage . . . . . . . . . . . . . . . . . . . . . . 96
Securing Child Restraints . . . . . . . . . . . . . . 88, 92
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Vehicle Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 Accessories and Modifications . . . . . . . . . 323
Climate Control System . . . . . . . . . . . . . . . . 204
Doing Your Own Work . . . . . . . . . . . . . . . . . 323
Maintenance Records . . . . . . . . . . . . . . . . . . 422
Maintenance, General Information . . . . . 408
Parts Identification . . . . . . . . . . . . . . . . . . . . . 423
Scheduling Appointments . . . . . . . . . . . . . . 433
Service Electric Parking Brake Light . . . . . . . 118
Services Special Application . . . . . . . . . . . . . . . . . . . . . 415
Servicing System . . . . . . . . . . . . . . . . . . . . . . . . . 175
Servicing the Airbag . . . . . . . . . . . . . . . . . . . . . . 69
Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Shift Lock Control Function Check, Automatic Transmission . . . . . . . . . . . . . . . . 347
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Out of Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Side Blind Zone Alert (SBZA) . . . . . . . . . . . . . 280 Signals, Turn and Lane-Change . . . . . . . . . . . .143
Snow Plow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .318
Software Updates . . . . . . . . . . . . . . . . . . . . . . . . . 155
Special Application Services . . . . . . . . . . . . . . .415
Specifications and Capacities . . . . . . . . . . . . . 424
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110
Start Assist, Hill . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Start Vehicle, Remote . . . . . . . . . . . . . . . . . . . . . 20
Starter Switch Check . . . . . . . . . . . . . . . . . . . . . 347
Starting the Engine . . . . . . . . . . . . . . . . . . . . . . 232
Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .214
Heated Wheel . . . . . . . . . . . . . . . . . . . . . . . . . 100
Wheel Adjustment . . . . . . . . . . . . . . . . . . . . . 100
Wheel Controls . . . . . . . . . . . . . . . . . . . . . . . . 100
Steering Column Lock . . . . . . . . . . . . . . . . . . . . . .32
Steering Wheel Controls . . . . . . . . . . . . . . . . . . 151
Steps Power Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Stop/Start System . . . . . . . . . . . . . . . . . . . . . . . 233
Stoplamps and Back-up Lamps Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . 351
Storage Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Storage Areas Center Console . . . . . . . . . . . . . . . . . . . . . . . . . 96
Floor Console . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Glove Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Underseat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96