
GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
30 Keys, Doors, and Windows
When applying any load to the tailgate,
distribute the weight evenly across the
width of the tailgate. This applies to all
tailgate types.
.Use a load-distributing member (1).
.Secure the ramp to the bumper (2).
Power Assist Steps
{Warning
To avoid personal injury or property
damage, before entering or exiting the
vehicle, be sure the power assist step is
fully extended. Do not step on the power
assist step while it is moving. Never place
hands or other body parts between the
extended power assist step and the
vehicle.
If equipped, the power assist steps, when
enabled, will extend when the door is
opened. They will retract three seconds after
the door is closed or immediately if the
vehicle starts moving.
Keep hands, children, pets, objects, and
clothing clear of the power assist steps
when in motion. The steps will reverse direction if there is an
obstruction. If possible, carefully remove the
obstruction, then open and close the door
on the same side to complete the motion.
If the obstruction is not cleared, the assist
steps remain extended.
Slight movement of the steps while
extended is normal.
Kick Switch
1. Place the vehicle in P (Park) and unlock
the doors. 2. Kick the switch to extend the power
assist step to the tire. A Driver
Information Center (DIC) message
displays.
3. Kick the switch again to return to normal operation.
Center Stack Switch
The power assist steps can be extended to
the tire by pressing
j. When extending
the steps with
j, the kick switch is
disabled. The vehicle must be in P (Park) or
N (Neutral).

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
384 Vehicle Care
If the wheel has a smooth center cap,
concealing access to the wheel nuts,
place the chisel end of the wheel wrench
in the slot on the wheel, and gently pry
it out.
If the wheel’s center cap does not
conceal the wheel nuts, the center cap
may remain during wheel removal. If the
removed wheel is to be stowed in the
hoist, the cap needs to be detached from
the wheel. Access the wheel from the
back side, and use a jack handle
extension to push out the center cap.
3. Use the wheel wrench and turn itcounterclockwise to loosen the wheel
nuts. Do not remove the wheel nuts yet.
{Warning
To avoid personal injury and vehicle
damage, disable the power assist steps
before using a jack or placing an object
under the vehicle. See Power Assist Steps
0 30.
Front Position
4. If the flat tire is on the front of the vehicle, position the jack under the
bracket attached to the vehicle's frame,
behind the flat tire, as shown.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
456 Index
PowerDoor Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Outlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Protection, Battery . . . . . . . . . . . . . . . . . . . . . 147
Retained Accessory (RAP) . . . . . . . . . . . . . . 236
Seat Adjustment . . . . . . . . . . . . . . . . . . . . . . . . 47
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Power Assist Steps . . . . . . . . . . . . . . . . . . . . . . . . 30
Pregnancy, Using Seat Belts . . . . . . . . . . . . . . 59
Privacy Vehicle Data Recording . . . . . . . . . . . . . . . . 437
Problems with Route Guidance . . . . . . . . . . .174
Program Courtesy Transportation . . . . . . . . . . . . . . . 433
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . . . 284
Proposition 65 Warning,
California . . . . . . . . . . . . . . . . . . . . .322, 343, 391, Back Cover
Publication Ordering Information . . . . . . . . 435
R
Radio HD Radio Technology . . . . . . . . . . . . . . . . . . 156
Radio Data System (RDS) . . . . . . . . . . . . . . . . . 157
Radio Frequency Statement . . . . . . . . . . . . . . 436
Radio Reception . . . . . . . . . . . . . . . . . . . . . . . . . .158 Radios
AM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Satellite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Reading Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
Rear Camera Mirror . . . . . . . . . . . . . . . . . . . . . . . 38
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Heated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Rear Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Rear Vision Camera (RVC) . . . . . . . . . . . . . . . . 266
Rear Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Rearview Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . 38 Automatic Dimming . . . . . . . . . . . . . . . . . . . . 38
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . . . 48
Recognition Voice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Recommended Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283, 284
Recommended Fluids and Lubricants . . . . . 418
Records Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
Recreational Vehicle Towing . . . . . . . . . . . . . 395
Reimbursement Program, GM Mobility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .431
Remote Keyless Entry (RKE) System . . . 10, 13
Remote Vehicle Start . . . . . . . . . . . . . . . . . . . . . 20 Replacement
Glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Replacement Parts Airbags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 419
Replacing Airbag System . . . . . . . . . . . . . . . . . . . 71
Replacing LATCH System Parts after a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Replacing Seat Belt System Parts after a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Reporting Safety Defects
Canadian Government . . . . . . . . . . . . . . . . . 437
General Motors . . . . . . . . . . . . . . . . . . . . . . . . 437
U.S. Government . . . . . . . . . . . . . . . . . . . . . . . 436
Restraints Where to Put . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Retained Accessory Power (RAP) . . . . . . . . . 236
Reverse Tilt Mirrors . . . . . . . . . . . . . . . . . . . . . . . 38
Ride Control Systems Enhanced Traction System (ETS) . . . . . . . 254
Roads
Driving, Wet . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Roadside Assistance Program . . . . . . . . . . . . .431
Roof Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Rotation, Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
Routing, Engine Drive Belt . . . . . . . . . . . . . . . 427
Running the Vehicle While Parked . . . . . . . 238

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