
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
182 Climate Controls
Caution
Using a razor blade or sharp
object to clear the inside rear
window can damage the rear
window defogger. Repairs would
not be covered by the vehicle
warranty. Do not clear the inside
rear window with sharp objects.
Remote Start Climate Control
Operation : If equipped with remote
start, the climate control system
may run when the vehicle is started
remotely. If equipped with heated or
ventilated seats or a heated steering
wheel, these features may come on
during a remote start. See Remote
Vehicle Start 025, Heated and
Ventilated Front Seats 060, and
Heated Steering Wheel 0119.
Sensors
The solar sensor, on top of the
instrument panel near the
windshield, monitors the solar heat.
The climate control system uses the
sensor information to adjust the
temperature, fan speed,
recirculation, and air delivery mode
for best comfort.
Do not cover the sensor; otherwise
the automatic climate control system
may not work properly.
Air Vents
Use the sliding knobs on the center
and side air vents to change the
direction of the airflow.
Air vents blow warm air on the side
windows in cold weather. If Floor,
Defog, or Defrost modes are
selected, a small amount of air will
come from the vents close to the
window.
To close the front a/c vents, move
the sliding knobs to the full down
position.
To close the rear a/c vents, move
the sliding knobs to the full inboard
position.
Operation Tips
.
Clear away any ice, snow,
or leaves from air inlets at the
base of the windshield that could
block the flow of air into the
vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Vehicle Care 377
BackThe vehicle may not be equipped
with all of the fuses, relays, and
features shown.
Fuses Usage
F1 Right doors
F2 Left doors
F3 Universal remote system
F4 –
F5 –
F6 Front blower
F8 Lumbar switch
F10 Body control module 6/Body control
module 7
F11 Seat/CLM
F12 Body control module 3/Body control
module 5
F14 Mirrors/Windows module
F17 Steering wheel controls
F18 VPM/OBS DET Fuses Usage
F19 DLIS
F20 Ventilated seats
F21 NOT R/C
F22 Heated steering wheel
F23 MISC R/C
F24 Instrument panel cluster ignition/
Overhead
F25 Heating, ventilation, and air conditioning
ignition/Heating,
ventilation, and air
conditioning auxiliary
F26 USB ports/Special equipment option
retained accessory
power
F27 Accessory power outlet/retained
accessory power
F28 Accessory power outlet/Battery

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 8/27/19
492 Index
Glove Box . . . . . . . . . . . . . . . . . . . . . . 112
GM Mobility ReimbursementProgram . . . . . . . . . . . . . . . . . . . . . . . 465
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . 367
Hazard Warning Flashers . . . . . . . 169
Head Restraints . . . . . . . . . . . . . . . . . 53
Head-up Display . . . . . . . . . . . . . . . . 152
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . 366
Automatic . . . . . . . . . . . . . . . . . . . . . 168
Bulb Replacement . . . . . . . . . . . . 367
Daytime RunningLamps (DRL) . . . . . . . . . . . . . . . . 168
Flash-to-Pass . . . . . . . . . . . . . . . . . 168
Headlamps, Front Turn Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . . . 367
High-Beam On Light . . . . . . . . . . 146
High/Low Beam Changer . . . . . 167
Lamps On Reminder . . . . . . . . . 146
Heated Rear Seats . . . . . . . . . . . . . . . . . . . . . 63
Steering Wheel . . . . . . . . . . . . . . . .119
Heated and Ventilated Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Heated Mirrors . . . . . . . . . . . . . . . . . . . 43 Heater
Engine . . . . . . . . . . . . . . . . . . . . . . . . 215
Heating . . . . . . . . . . . . . . . . . . . . 177, 179
High-Beam On Light . . . . . . . . . . . . 146
High-Speed Operation . . . . . . . . . . 389
Hill and Mountain Roads . . . . . . . . 197
Hill Descent Control (HDC) . . . . . 237
Hill Descent Control Light . . . . . . . 141
Hill Start Assist (HSA) . . . . . . . . . . 235
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
How to Wear Seat Belts Properly . . . . . . . . . . . . . . . . . . . . . . . . 65
HVAC . . . . . . . . . . . . . . . . . . . . . . 177, 179
I
Ignition Positions . . . . . . . . . . 208, 210
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . . . 363
Immobilizer . . . . . . . . . . . . . . . . . . . . . . 37
Indicator Pedestrian Ahead . . . . . . . . . . . . 142
Vehicle Ahead . . . . . . . . . . . . . . . . 142
Infants and Young Children, Restraints . . . . . . . . . . . . . . . . . . . . . . 86
Information
Publication Ordering . . . . . . . . . . 471
Infotainment . . . . . . . . . . . . . . . . . . . . 176 Infotainment System . . . . . . . . . . . . 475
Instrument Cluster . . . . . . . . . . . . . . 126
Instrument Panel Overview . . . . . . . 5
Interior Rearview Mirrors . . . . . . . . . 44
Introduction . . . . . . . . . . . . . . . . . . . . . . . 2
J
Jump Starting - North
America . . . . . . . . . . . . . . . . . . . . . . . 419
K
Keyless EntryRemote (RKE) System . . . . . 13, 16
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . .9, 12
L
Labeling, Tire Sidewall . . . . . . . . . . 381
Lamps Daytime Running (DRL) . . . . . . 168
Dome . . . . . . . . . . . . . . . . . . . . . . . . . 172
Exterior Cargo . . . . . . . . . . . . . . . . 171
Exterior Controls . . . . . . . . . . . . . . 165
Exterior Lamps OffReminder . . . . . . . . . . . . . . . . . . . 167
Exterior Lighting Battery Saver . . . . . . . . . . . . . . . . . . . . . . . 174
License Plate . . . . . . . . . . . . . . . . . 369
Malfunction Indicator (Check Engine) . . . . . . . . . . . . . 137

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 8/27/19
Index 495
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Passenger Sensing System . . . . . 77
Pedestrian Ahead Indicator . . . . . 142
Perchlorate Materials Requirements, California . . . . . . 329
Personalization
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 156
Pickup Conversion to Chassis Cab . . . . . . . . . . . . . . . . . . 326
Power
Door Locks . . . . . . . . . . . . . . . . . . . . . 27
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Outlets . . . . . . . . . . . . . . . . . . . . . . . 121
Protection, Battery . . . . . . . . . . . . 174
Retained Accessory (RAP) . . . 216
Seat Adjustment . . . . . . . . . . . . . . . . 55
Steering Fluid . . . . . . . . . . . . . . . . . 354
Windows . . . . . . . . . . . . . . . . . . . . . . . 47
Power Assist Steps . . . . . . . . . . . . . . 34
Pregnancy, Using Seat Belts . . . . 69
Privacy Vehicle Data Recording . . . . . . . 473
Program Courtesy Transportation . . . . . . 468
Prohibited Fuels . . . . . . . . . . . . . . . . 281 Proposition
65 Warning,
California . . . . . . . . . . . .329, 358, 419,
Back Cover
Publication Ordering Information . . . . . . . . . . . . . . . . . . . . 471
R
Radio Frequency Statement . . . . 472
Reading Lamps . . . . . . . . . . . . . . . . . 173
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . 362Locking . . . . . . . . . . . . . . . . . . . . . . . 242
Rear Camera Mirror . . . . . . . . . . . . . 45
Rear Seats . . . . . . . . . . . . . . . . . . . . . . 62 Heated . . . . . . . . . . . . . . . . . . . . . . . . . 63
Rear Storage . . . . . . . . . . . . . . . . . . . 113
Rear Vision Camera (RVC) . . . . . 257
Rear Windows . . . . . . . . . . . . . . . . . . . 49
Rearview Mirrors . . . . . . . . . . . . . . . . 44 Automatic Dimming . . . . . . . . . . . . . 44
Reclining Seatbacks . . . . . . . . . . . . . 56
Recommended
Fuel . . . . . . . . . . . . . . . . . . . . . 280, 281
Recommended Fluids and Lubricants . . . . . . . . . . . . . . . . . . . . . 452
Records
Maintenance . . . . . . . . . . . . . . . . . . 456 Recreational Vehicle Towing . . . . 424
Reimbursement Program,
GM Mobility . . . . . . . . . . . . . . . . . . . 465
Remote Keyless Entry (RKE) System . . . . . . . . . . . . . . 13, 16
Remote Vehicle Start . . . . . . . . . . . . 25
Replacement Parts Airbags . . . . . . . . . . . . . . . . . . . . . . . . . 83
Maintenance . . . . . . . . . . . . . . . . . . 454
Replacing Airbag System . . . . . . . . 83
Replacing LATCH System Parts after a Crash . . . . . . . . . . . . 104
Replacing Seat Belt System Parts after a Crash . . . . . . . . . . . . . 71
Reporting Safety Defects Canadian Government . . . . . . . . 472
General Motors . . . . . . . . . . . . . . . 473
U.S. Government . . . . . . . . . . . . . 472
Restraints Where to Put . . . . . . . . . . . . . . . . . . . 90
Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . . . . 216
Reverse Tilt Mirrors . . . . . . . . . . . . . . 44
Ride Control Systems Enhanced Traction
System (ETS) . . . . . . . . . . . . . . . 242

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 8/27/19
496 Index
RoadsDriving, Wet . . . . . . . . . . . . . . . . . . 196
Roadside Assistance Program . . . . . . . . . . . . . . . . . . . . . . . 466
Roof Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . 50
Rotation, Tires . . . . . . . . . . . . . . . . . . 396
Routing, Engine Drive Belt . . . . . . 461
Running the Vehicle While
Parked . . . . . . . . . . . . . . . . . . . . . . . . 220
S
Safety Defects ReportingCanadian Government . . . . . . . . 472
General Motors . . . . . . . . . . . . . . . 473
U.S. Government . . . . . . . . . . . . . 472
Safety Locks . . . . . . . . . . . . . . . . . . . . . 28
Safety System Check . . . . . . . . . . . . 70
Scheduling Appointments . . . . . . . 467
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . 64 Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Extender . . . . . . . . . . . . . . . . . . . . . . . . 70
How to Wear Seat Belts
Properly . . . . . . . . . . . . . . . . . . . . . . . 65
Lap-Shoulder Belt . . . . . . . . . . . . . . 67
Reminders . . . . . . . . . . . . . . . . . . . . 135
Replacing after a Crash . . . . . . . . 71
Use During Pregnancy . . . . . . . . . . 69 Seats
Adjustment, Front . . . . . . . . . . . . . . . 54
Center Seat . . . . . . . . . . . . . . . . . . . . 55
Head Restraints . . . . . . . . . . . . . . . . 53
Heated and Ventilated Front . . . . 60
Heated, Rear . . . . . . . . . . . . . . . . . . . 63
Lumbar Adjustment, Front . . . . . . 56
Memory . . . . . . . . . . . . . . . . . . . . . . . . . 58
Power Adjustment, Front . . . . . . . 55
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Reclining Seatbacks . . . . . . . . . . . . 56
Underseat Storage . . . . . . . . . . . .113
Securing Child Restraints . . . . . . . . . . .104, 107, 108
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . 146
OnStar . . . . . . . . . . . . . . . . . . . . . . . 478
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . 36
Vehicle Alarm . . . . . . . . . . . . . . . . . . . 36
Service . . . . . . . . . . . . . . . . . . . . . . . . . 184 Accessories and
Modifications . . . . . . . . . . . . . . . . 329
Climate Control System . . . . . . . 177
Doing Your Own Work . . . . . . . . 330
Maintenance Records . . . . . . . . 456
Maintenance, General Information . . . . . . . . . . . . . . . . . . 439
Parts Identification . . . . . . . . . . . . 457 Service (cont'd)
Scheduling Appointments . . . . . 467
Service Electric Parking Brake Light . . . . . . . . . . . . . . . . . . . . 140
Services Special Application . . . . . . . . . . . 448
Servicing the Airbag . . . . . . . . . . . . . 82
Shift Lock Control Function Check, Automatic
Transmission . . . . . . . . . . . . . . . . . . 363
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . . 217
Out of Park . . . . . . . . . . . . . . . . . . . 218
Side Blind Zone Alert (SBZA) . . . 274
Signals, Turn and
Lane-Change . . . . . . . . . . . . . . . . . 170
Snow Plow . . . . . . . . . . . . . . . . . . . . . 323
Special Application Services . . . . 448
Specifications and Capacities . . . . . . . . . . . . . . . . . . . . . 458
Speedometer . . . . . . . . . . . . . . . . . . . 130
Start Assist, Hill . . . . . . . . . . . . . . . . . 235
Start Vehicle, Remote . . . . . . . . . . . 25
Starter Switch Check . . . . . . . . . . . 363
Starting the Engine . . . . . . . . . . . . . 212
Steering . . . . . . . . . . . . . . . . . . . . . . . . 188 Fluid, Power . . . . . . . . . . . . . . . . . . 354
Heated Wheel . . . . . . . . . . . . . . . . .119

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 8/27/19
498 Index
TractionLimited-Slip Differential . . . . . . . 242
Off Light . . . . . . . . . . . . . . . . . . . . . . 142
Traction Control/Electronic Stability Control . . . . . . . . . . . . . . . 235
Trailer Sway Control (TSC) . . . . . . . . . . 308
Tow Mirrors . . . . . . . . . . . . . . . . . . . . . 40
Towing . . . . . . . . . . . . . . . . . . . . . . . . 292
Trailer Towing App . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Trailering App . . . . . . . . . . . . . . . . . . 310
Transfer Case . . . . . . . . . . . . . . . . . . 227
Transmission Automatic . . . . . . . . . . . . . . . . . . . . . 221
Fluid, Automatic . . . . . . . . . . . . . . 343
Transportation Program, Courtesy . . . . . . . . . . . . . . . . . . . . . . 468
Trip Odometer . . . . . . . . . . . . . . . . . . 131
Truck-Camper Loading Information . . . . . . . . . . . . . . . . . . . . 206
Turn and Lane-Change Signals . . . . . . . . . . . . . . . . . . . . . . . . 170
Turn Signal Bulb Replacement . . . . . . . . . . . . 368U
Underseat Storage . . . . . . . . . . . . . 113
Uniform Tire Quality Grading . . . 402
Universal Remote System . . . . . . 161Operation . . . . . . . . . . . . . . . . . . . . . 164
Programming . . . . . . . . . . . . . . . . . 161
Using This Manual . . . . . . . . . . . . . . . . 2
V
Vehicle Alarm System . . . . . . . . . . . . . . . . . . 36
Canadian Owners . . . . . . . . . . . . . . . 2
Control . . . . . . . . . . . . . . . . . . . . . . . 188
Identification Number (VIN) . . . 457
Load Limits . . . . . . . . . . . . . . . . . . . 200
Messages . . . . . . . . . . . . . . . . . . . . 155
Personalization . . . . . . . . . . . . . . . 156
Remote Start . . . . . . . . . . . . . . . . . . . 25
Security . . . . . . . . . . . . . . . . . . . . . . . . 36
Speed Messages . . . . . . . . . . . . . 156
Towing . . . . . . . . . . . . . . . . . . . . . . . . 424
Vehicle Ahead Indicator . . . . . . . . 142
Vehicle Care Tire Pressure . . . . . . . . . . . . . . . . . 387
Vehicle Data Recording and Privacy . . . . . . . . . . . . . . . . . . . . . . . . 473
Vehicle Security Steering Column Lock . . . . . . . . . . 37 Ventilation, Air . . . . . . . . . . . . . . . . . . 182
Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Voltmeter Gauge . . . . . . . . . . . . . . . 134
W
Warning
Brake System Light . . . . . . . . . . . 139
Caution and Danger . . . . . . . . . . . . . 3
Lane Departure (LDW) . . . . . . . 276
Warning Lights, Gauges, and Indicators . . . . . . . . . . . . . . . . . . . . . 125
Warnings
Hazard Flashers . . . . . . . . . . . . . . 169
Washer Fluid . . . . . . . . . . . . . . . . . . . 354
Wheels Alignment and Tire Balance . . 403
Different Size . . . . . . . . . . . . . . . . . 401
Replacement . . . . . . . . . . . . . . . . . 403
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 399
Where to Put the Restraint . . . . . . 90
Windows . . . . . . . . . . . . . . . . . . . . . . . . 47
Manual . . . . . . . . . . . . . . . . . . . . . . . . . 47
Power . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Windshield
Replacement . . . . . . . . . . . . . . . . . 365
Wiper/Washer . . . . . . . . . . . . . . . . .119