204 GMC SIERRA 2021 Owner's Manual

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 2/18/21
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Keys, Doors, and Windows . . . . . . . . . . . . . . . 7
Seats and Restraints . . . . . . . . . . . . . . . . . . . . . 45
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Instruments and Controls . . . . . . . . . . . . . . . 99
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Infotainment System . . . . . . . . . . . . . . . . . . . 148
Climate Controls . . . . . . . . . . . . . . . . . . . . . . . 204
Driving and Operating . . . . . . . . . . . . . . . . . . 211
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Service and Maintenance . . . . . . . . . . . . . . 408
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . 423
Customer Information . . . . . . . . . . . . . . . . . . 428
Reporting Safety Defects . . . . . . . . . . . . . . . 436
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440
Connected Services . . . . . . . . . . . . . . . . . . . . . 445
Index . . . . . . . . . . . . . . . . . . . . . . . . . . 448
Introduction
The names, logos, emblems, slogans, vehicle
model names, and vehicle body designs
appearing in this manual including, but not
limited to, GM, the GM logo, GMC, the GMC
Truck Emblem, SIERRA, and DENALI are
trademarks and/or service marks of General
Motors LLC, its subsidiaries, affiliates,
or licensors.
For vehicles first sold in Canada, substitute
the name“General Motors of Canada
Company” for GMC Division wherever it
appears in this manual. This manual describes features that may or
may not be on the vehicle because of
optional equipment that was not purchased
on the vehicle, model variants, country
specifications, features/applications that may
not be available in your region, or changes
subsequent to the printing of this owner’s
manual.
If the vehicle has the Duramax diesel
engine, see the Duramax diesel supplement
for additional and specific information on
this engine.
Refer to the purchase documentation
relating to your specific vehicle to confirm
the features.
Keep this manual in the vehicle for quick
reference.
Litho in U.S.A.
Part No. 84550392 C Third Printing©2021 General Motors LLC. All Rights Reserved.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Introduction 5
1. Tow/Haul Mode (On Some Models). SeeDriver Mode Control 0251.
Automatic Transfer Case Control (If
Equipped). See Four-Wheel Drive 0242.
Driver Mode Control 0251 (If Equipped).
2. Air Vents 0209.
3. Head-Up Display (HUD) 0128 (If
Equipped).
4. Turn Signal Lever. See Turn and
Lane-Change Signals 0143.
Windshield Wiper/Washer 0101.
5. Instrument Cluster 0106.
6. Shift Lever. See Automatic Transmission
0 239.
Range Selection Mode. See Manual Mode
0 241.
7. Light Sensor. See Automatic Headlamp
System 0142.
8. Infotainment Controls. See Overview
0 149.
9. Climate Control Systems 0204 (If
Equipped).
Dual Automatic Climate Control System
0 206 (If Equipped).
10. Heated and Ventilated Front Seats 052
(If Equipped). 11.ALane Keep Assist (LKA)
0281 (If
Equipped).
XPark Assist Switch (If Equipped). See
Assistance Systems for Parking or Backing
0 266.
hAuto Stop Disable Switch (If
Equipped). See Stop/Start System 0233.
5Power Release Tailgate (If
Equipped). See Tailgate023.
|Hazard Warning Flashers 0142.
gTraction Control/Electronic Stability
Control 0248.
ADC/AC Switch. See Power Outlets
0 102.
5Hill Descent Control Switch (If
Equipped). See Hill Descent Control (HDC)
0 250.
jPower Assist Steps 030 (If
Equipped).
LExpress Window Down Button (If
Equipped). See Power Windows 041.
Tow/Haul Mode 0242 (On Some
Models).
Exhaust Brake (If Equipped). See Duramax
Diesel Supplement. Power Take-Off (PTO) (If Equipped). See
Duramax Diesel Supplement.
12. Power Outlet (Alternating Current) (If Equipped). See Power Outlets0102.
13. Power Outlet (Direct Current) Power
Outlets 0102.
14. USB Port 0158.
15. Wireless Charging 0103 (If Equipped).
16. Trailer Brake Control Panel (If Equipped). See“Integrated Trailer Brake Control
System” underTowing Equipment 0296.
17. ENGINE START/STOP. See Ignition
Positions (Keyless Access) 0230 or
Ignition Positions (Key Access) 0229.
18. Steering Wheel Controls 0100 (If
Equipped).
Driver Information Center (DIC) Controls.
See Driver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
19. Horn 0101.
20. Hood Release. See Hood0323.
21. Steering Wheel Adjustment 0100 (Out
of View).

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
204 Climate Controls
Climate Controls
Climate Control Systems
Climate Control Systems . . . . . . . . . . . . . . 204
Dual Automatic Climate ControlSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Maintenance
Passenger Compartment Air Filter . . . . . 209
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Climate Control Systems
The heating, cooling, and ventilation in the vehicle can be controlled with this system.
1. Fan Control
2. MAX Defrost
3. Air Delivery Mode Controls
4. A/C (Air Conditioning)
5. TEMP (Temperature Control)
6. Recirculation
7. Rear Window Defogger (If Equipped) or Heated Mirrors (If Equipped)9:Turn clockwise or counterclockwise to
increase or decrease the fan speed. Turn the
knob all the way counterclockwise to turn
the fan off.
TEMP : Turn clockwise or counterclockwise
to increase or decrease the temperature
inside the vehicle.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
412 Service and Maintenance
Additional Required ServicesMaintenance Schedule Additional
Required Services - Normal
12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi 60 000 km/37,500 mi
72 000 km/45,000 mi84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi 120 000 km/75,000 mi 132 000 km/82,500 mi
144 000 km/90,000 mi 156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi 204 000 km/127,500 mi 216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services. Check engine oil
level and oil life percentage. Change engine oil and filter,
if needed.
Check engine air filter life percentage and status. Change
engine air filter, if needed. (1)
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or boots.
(Except 2.7L L4 Turbo Engine)@
Replace spark plugs. Inspect spark plug wires and/or boots.
(2.7L L4 Turbo Engine Only)@ @
Change transfer case fluid, if equipped with 4WD. (4)@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood gas struts and tailgate dampener. (9)@ @
Replace air conditioning desiccant. (10)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
414 Service and Maintenance
Maintenance Schedule Additional
Required Services - Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi 60 000 km/37,500 mi
72 000 km/45,000 mi84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi 120 000 km/75,000 mi 132 000 km/82,500 mi
144 000 km/90,000 mi 156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi 204 000 km/127,500 mi 216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services. Check engine oil
level and oil life percentage. Change engine oil and filter,
if needed.
Check engine air filter life percentage and status. Change
engine air filter, if needed. (1)
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or boots.
(Except 2.7L L4 Turbo Engine)@
Replace spark plugs. Inspect spark plug wires and/or boots.
(2.7L L4 Turbo Engine Only)@ @
Change automatic transmission fluid and filter.@@@
Change transfer case fluid, if equipped with 4WD. (4)@@@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood gas struts and tailgate dampener. (9)@ @
Replace air conditioning desiccant. (10)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
448 Index
IndexA
Accessories and Modifications . . . . . . . . . . . 323
Accessory Power . . . . . . . . . . . . . . . . . . . . . . . . . 236
Active Fuel Management . . . . . . . . . . . . . . . . 237
Adaptive Cruise Control . . . . . . . . . . . . . . . . . . 256
Add-On Electrical Equipment . . . . . . . . . . . . . .318
Adding a Snow Plow or SimilarEquipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .318
Additional Information OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441
Additional Maintenance and Care . . . . . . . . .415
Adjustments Lumbar, Front Seats . . . . . . . . . . . . . . . . . . . . 48
Agreements
Trademarks and License . . . . . . . . . . . . . . . 195
Air Cleaner/Filter, Engine . . . . . . . . . . . . . . . . 334
Air Conditioning . . . . . . . . . . . . . . . . . . . . 204, 206
Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Air Filter, Passenger Compartment . . . . . . . 209
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
How Does an Airbag Restrain? . . . . . . . . . . 64
Passenger Sensing System . . . . . . . . . . . . . . 66
What Makes an Airbag Inflate? . . . . . . . . . 64
What Will You See after an AirbagInflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Airbag System (cont'd)
When Should an Airbag Inflate? . . . . . . . . 63
Where Are the Airbags? . . . . . . . . . . . . . . . . 62
Airbags Adding Equipment to the Vehicle . . . . . . . 69
Passenger Status Indicator . . . . . . . . . . . . . . 114
Readiness Light . . . . . . . . . . . . . . . . . . . . . . . . . 114
Servicing Airbag-Equipped Vehicles . . . . . . 69
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Alarm Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . . 31
Alert
Lane Change . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Side Blind Zone (SBZA) . . . . . . . . . . . . . . . . . 280
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 361
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 362
AM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Antenna Fixed Mast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Multi-band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Antilock Brake System (ABS) . . . . . . . . . . . . . 246
Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
Apple CarPlay and Android Auto . . . . . . . . . .185

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
450 Index
Caution, Danger, and Warning . . . . . . . . . . . . . .2
Center Console Storage . . . . . . . . . . . . . . . . . . . 96
Center High-Mounted Stoplamp(CHMSL) and Cargo Lamp . . . . . . . . . . . . . . 352
Center Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Charging System Light . . . . . . . . . . . . . . . . . . . . 115
Check Engine Light (Malfunction Indicator) . . . . 115
Ignition Transmission Lock . . . . . . . . . . . . . 347
Child Restraints Infants and Young Children . . . . . . . . . . . . . 72
Lower Anchors and Tethers forChildren . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Securing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88, 92
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Cleaning Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
Climate Control Systems . . . . . . . . . . . . . . . . . 204 Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . 204
Dual Automatic . . . . . . . . . . . . . . . . . . . . . . . . 206
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Cluster, Instrument . . . . . . . . . . . . . . . . . . . . . . 106
Collision Damage Repair . . . . . . . . . . . . . . . . . 434
Compartments
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Connected Services Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 446
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447
Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445
Connections Connected Services . . . . . . . . . . . . . . . . . . . . 446
Control Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Traction and Electronic Stability . . . . . . . 248
Control Light Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Control of a Vehicle . . . . . . . . . . . . . . . . . . . . . . 213
Controls Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . . 151
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Coolant Engine Temperature Gauge . . . . . . . . . . . . . 112
Engine Temperature Warning Light . . . . . 121
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204, 206
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Courtesy Transportation Program . . . . . . . . 433
Coverage Explanations . . . . . . . . . . . . . . . . . . . . 175
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 Cruise Control (cont'd)
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Cruise Control, Adaptive . . . . . . . . . . . . . . . . . 256
Cupholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Customer Assistance . . . . . . . . . . . . . . . . . . . . . 430 Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
Text Telephone (TTY) Users . . . . . . . . . . . . 430
Customer Information Publications Ordering Information . . . . . 435
Customer Satisfaction Procedure . . . . . . . . . 428
Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438
D
Damage Repair, Collision . . . . . . . . . . . . . . . . . 434
Danger, Warning, and Caution . . . . . . . . . . . . . .2
Data Collection Infotainment System . . . . . . . . . . . . . . . . . . 439
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439
Data Recorders, Event . . . . . . . . . . . . . . . . . . . 438
Database Coverage Explanations . . . . . . . . . . 175
Daytime Running Lamps (DRL) . . . . . . . . . . . . 141
Defensive Driving . . . . . . . . . . . . . . . . . . . . . . . . . 213
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Destination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Diagnostics Connected Services . . . . . . . . . . . . . . . . . . . . 447
Differential, Limited-Slip . . . . . . . . . . . . . . . . . 254
Distracted Driving . . . . . . . . . . . . . . . . . . . . . . . . . 212

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
Index 453
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Hazard Warning Flashers . . . . . . . . . . . . . . . . .142
HD Radio Technology . . . . . . . . . . . . . . . . . . . . 156
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Head-up Display . . . . . . . . . . . . . . . . . . . . . . . . . .128
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . 350
Daytime Running Lamps (DRL) . . . . . . . . . . 141
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Headlamps, Front Turn Signal,Sidemarker, and Parking Lamps . . . . . . 350
High-Beam On Light . . . . . . . . . . . . . . . . . . . 123
High/Low Beam Changer . . . . . . . . . . . . . . . 141
Lamps On Reminder . . . . . . . . . . . . . . . . . . . 123
Heated Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . 100
Heated and Ventilated Front Seats . . . . . . . .52
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204, 206
High-Beam On Light . . . . . . . . . . . . . . . . . . . . . . 123
Hill and Mountain Roads . . . . . . . . . . . . . . . . 219
Hill Descent Control (HDC) . . . . . . . . . . . . . . . 250 Hill Descent Control Light . . . . . . . . . . . . . . . . . 119
Hill Start Assist (HSA) . . . . . . . . . . . . . . . . . . . . 248
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101
How to Wear Seat Belts Properly . . . . . . . . . .55
HVAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204, 206
I
If the System Needs Service . . . . . . . . . . . . . . 175
Ignition Positions . . . . . . . . . . . . . . . . . . . 229, 230
Ignition Transmission Lock Check . . . . . . . . 347
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Indicator
Pedestrian Ahead . . . . . . . . . . . . . . . . . . . . . . . 119
Vehicle Ahead . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Infants and Young Children, Restraints . . . . .72
Information Publication Ordering . . . . . . . . . . . . . . . . . . . 435
Infotainment System . . . . . . . . . . . . . . . . . . . . 439
Instrument Cluster . . . . . . . . . . . . . . . . . . . . . . . 106
Instrument Panel Overview . . . . . . . . . . . . . . . . 4
Interior Rearview Mirrors . . . . . . . . . . . . . . . . . 38
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 1, 148
J
Jack Auxiliary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Jump Starting - North America . . . . . . . . . . . 391
K
Keyless Entry Remote (RKE) System . . . . . . . . . . . . . . . . 10, 13
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7, 9
L
Labeling, Tire Sidewall . . . . . . . . . . . . . . . . . . . 362
Lamps Auxiliary Roof Mounted Lamp . . . . . . . . . 144
Daytime Running (DRL) . . . . . . . . . . . . . . . . . 141
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Exterior Cargo . . . . . . . . . . . . . . . . . . . . . . . . . 144
Exterior Controls . . . . . . . . . . . . . . . . . . . . . . . 139
Exterior Lamps Off Reminder . . . . . . . . . . . 141
Exterior Lighting Battery Saver . . . . . . . . 147
License Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Malfunction Indicator (CheckEngine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
On Reminder . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Lane Change Alert (LCA) . . . . . . . . . . . . . . . . . 280
Lane Keep Assist (LKA) . . . . . . . . . . . . . . . . . . . .281
Lane Keep Assist Light . . . . . . . . . . . . . . . . . . . . 119
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . . . .57
LATCH System Replacing Parts after a Crash . . . . . . . . . . . 88
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

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