
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 223
Caution
Use the correct key, make sure it is all
the way in—or pushed all the way in
toward the steering column when turning
off the vehicle —and turn it only with
your hand.
1 (ACC/ACCESSORY) : This position allows
features such as the infotainment system to
operate while the vehicle is off. It also
unlocks the steering column, if equipped
with a locking steering column. Use this
position if the vehicle must be pushed or
towed. See Retained Accessory Power (RAP)
0 227.
From ON/RUN, push the key all the way in
toward the steering column, then turn the
key to ACC/ACCESSORY.
If the key is left in ACC/ACCESSORY with the
engine off, the battery could drain and the
vehicle may not start.
A warning chime will sound when the driver
door is opened and the key is in the
ignition.
2 (ON/RUN) : This position can be used to
operate the electrical accessories and to
display some instrument cluster warning
and indicator lights. This position can also be used for service and diagnostics, and to
verify the proper operation of the
malfunction indicator lamp as may be
required for emission inspection purposes.
The switch stays in this position when the
engine is running. The transmission is also
unlocked in this position.
If the key is left in ON/RUN with the engine
off, the battery could drain and the vehicle
may not start.
3 (START) :
This is the position that starts
the engine. When the engine starts, release
the key. The ignition returns to ON/RUN for
driving.
Ignition Positions (Keyless Access)
Vehicles equipped with Keyless Access have
pushbutton starting.
The remote key must be in the vehicle for
the system to operate. If the pushbutton
start is not working, the vehicle may be
near a strong radio antenna signal causing
interference to the Keyless Access system.
See Remote Keyless Entry (RKE) System
Operation (Key Access) 012 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 014.
To shift out of P (Park), the ignition must be
on or in Service Mode, and the brake pedal
must be applied.
{Warning
Turning off the vehicle while moving may
cause loss of power assist in the brake
and steering systems and disable the
airbags. While driving, only shut the
vehicle off in an emergency.
Stopping the Engine/LOCK/OFF (No Indicator
Lights) : When the vehicle is stopped, press
ENGINE START/STOP once to turn the
engine off.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Index 421
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Hazard Warning Flashers . . . . . . . . . . . . . . . . .142
HD Radio Technology . . . . . . . . . . . . . . . . . . . . 156
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Head-Up Display (HUD) . . . . . . . . . . . . . . . . . . . 132
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . 325
Daytime Running Lamps (DRL) . . . . . . . . . . 141
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Headlamps, Front Turn Signal,Sidemarker, and Parking Lamps . . . . . . 325
High-Beam On Light . . . . . . . . . . . . . . . . . . . . 127
High/Low Beam Changer . . . . . . . . . . . . . . . 141
Lamps On Reminder . . . . . . . . . . . . . . . . . . . 128
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . 105
Ventilated Front Seats . . . . . . . . . . . . . . . . . . 56
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196, 197
High-Beam On Light . . . . . . . . . . . . . . . . . . . . . . 127 Hill
Descent Control (HDC) . . . . . . . . . . . . . . . . . 242
Descent Control Light . . . . . . . . . . . . . . . . . . 123
Hill and Mountain Roads . . . . . . . . . . . . . . . . . 212
Hill Start Assist (HSA) . . . . . . . . . . . . . . . . . . . . 240
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
How to Wear Seat Belts Properly . . . . . . . . . 59
HVAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196, 197
I
If the System Needs Service . . . . . . . . . . . . . . 171
Ignition Positions . . . . . . . . . . . . . . . . . . . . 221, 223
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Indicator Vehicle Ahead . . . . . . . . . . . . . . . . . . . . . . . . . 124
Indicators
Warning Lights and Gauges . . . . . . . . . . . . . 111
Infants and Young Children, Restraints . . . . .77
Information Publication Ordering . . . . . . . . . . . . . . . . . . . 404
Infotainment Using the System . . . . . . . . . . . . . . . . . . . . . . 152
Infotainment System . . . . . . . . . . . . . . . . . . . . 407
Inspection Multi-Point Vehicle . . . . . . . . . . . . . . . . . . . . 387
Instrument Cluster . . . . . . . . . . . . . . . . . . . . . . . . 111
Instrument Panel Overview . . . . . . . . . . . . . . . . .5 Interior Rearview Mirrors . . . . . . . . . . . . . . . . . 40
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 2, 148
J
Jack
Auxiliary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Jump
Starting - North America . . . . . . . . . . . . . . . 367
K
Keyless EntryRemote (RKE) System Operation . . . . . 12, 14
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8, 11
L
Labeling, Tire Sidewall . . . . . . . . . . . . . . . . . . . 338
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
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Fog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
High/Low Beam Changer . . . . . . . . . . . . . . . 141
License Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . 327

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
424 Index
PhoneApple CarPlay and Android Auto . . . . . . . . 181
Bluetooth . . . . . . . . . . . . . . . . . . . . . . . . . . 176, 177
Pickup Conversion to Chassis Cab . . . . . . . . 300
Port USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Positioning
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Power Assist Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Outlets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Protection, Battery . . . . . . . . . . . . . . . . . . . . . 147
Retained Accessory (RAP) . . . . . . . . . . . . . . 227
Seat Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . 51
Steering Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Pregnancy, Using Seat Belts . . . . . . . . . . . . . . 64
Privacy Vehicle Data Recording . . . . . . . . . . . . . . . . 405
Problems with Route Guidance . . . . . . . . . . 170
Program Courtesy Transportation . . . . . . . . . . . . . . . 401
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . . . 264
Proposition 65 Warning
California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Proposition 65 Warning, California . . . . . . . 367
Publication Ordering Information . . . . . . . . 404
R
Radiator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Radio
AM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . 154
Data System (RDS) . . . . . . . . . . . . . . . . . . . . . . 157
Frequency Statement . . . . . . . . . . . . . . . . . . 404
HD Radio Technology . . . . . . . . . . . . . . . . . . 156
Reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Satellite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Reading Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Camera Mirror . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Cross Traffic Alert (RCTA) System . . . . . . 257
Heated Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Locking Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Vision Camera (RVC) . . . . . . . . . . . . . . . . . . . 248
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Rearview Mirror Truck Bed Camera . . . . . . . . . . . . . . . . . . . . . . 43
Rearview Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . .41
Automatic Dimming . . . . . . . . . . . . . . . . . . . . 41
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . . . .52 Recognition
Voice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Recommended Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Recommended Fluids and Lubricants . . . . . 389
Records Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
Recreational Vehicle Towing . . . . . . . . . . . . . . 371
Reimbursement Program, GM Mobility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
Remote
Keyless Entry (RKE) System . . . . . . . . . . . . . . 12
Keyless Entry (RKE) SystemOperation . . . . . . . . . . . . . . . . . . . . . . . . . . 12, 14
Vehicle Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Replacement
Glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Replacement Parts Airbags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 390
Replacing
Airbag System . . . . . . . . . . . . . . . . . . . . . . . . . . 75
LATCH System Parts After a Crash . . . . . . 92
Seat Belt System Parts after a Crash . . . . 65
Reporting Safety Defects
Canadian Government . . . . . . . . . . . . . . . . . 405
General Motors . . . . . . . . . . . . . . . . . . . . . . . . 405
U.S. Government . . . . . . . . . . . . . . . . . . . . . . . 404