2021 GMC SIERRA CD changer

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Instruments and Controls 123
The security light should come on briefly as
the engine is started. If it does not come on,
have the vehicle serviced by your dealer.
If the system is working normally, the
indicator light turns off.
If the light stays on and the engine does
not start, there could be a problem with the
theft-deterrent system. SeeImmobilizer
Operation 032.
High-Beam On Light
This light comes on when the high-beam
headlamps are in use. See Headlamp High/
Low-Beam Changer 0141.
IntelliBeam Light
This light comes on when the IntelliBeam
system, if equipped, is enabled. See Exterior
Lamp Controls 0139.
Front Fog Lamp Light
For vehicles with fog lamps, this light comes
on when the fog lamps are on.
The light goes out when the fog lamps are
turned off. See Fog Lamps0143.
Lamps On Reminder
This light comes on when the exterior lamps
are in use, except when only the Daytime
Running Lamps (DRL) are active. See Exterior
Lamp Controls 0139.
Cruise Control Light
The cruise control light is white when the
cruise control is on and ready, and turns
green when the cruise control is set and
active.
See Cruise Control 0254.
Adaptive Cruise Control Light
If equipped, this light is white when the
Adaptive Cruise Control (ACC) is on and
ready, and turns green when the ACC is set
and active. When ACC is engaged and the
driver accelerates, the indicator will turn
blue. See Adaptive Cruise Control (Camera)
0 256.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/6/20
Lighting 139
Lighting
Exterior Lighting
Exterior Lamp Controls . . . . . . . . . . . . . . . . 139
Exterior Lamps Off Reminder . . . . . . . . . . . 141
Headlamp High/Low-Beam Changer . . . . 141
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Daytime Running Lamps (DRL) . . . . . . . . . 141
Automatic Headlamp System . . . . . . . . . . 142
Hazard Warning Flashers . . . . . . . . . . . . . . 142
Turn and Lane-Change Signals . . . . . . . . . 143
Fog Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Task Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Auxiliary Roof-Mounted Lamp . . . . . . . . . 144
Exterior Cargo Lamps . . . . . . . . . . . . . . . . . . 144
Interior Lighting
Instrument Panel IlluminationControl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Reading Lamps . . . . . . . . . . . . . . . . . . . . . . . . 146
Lighting Features
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . 146
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Battery Load Management . . . . . . . . . . . . 146
Battery Power Protection . . . . . . . . . . . . . . 147
Exterior Lighting Battery Saver . . . . . . . . 147
Exterior Lighting
Exterior Lamp Controls
The exterior lamp control is on the
instrument panel to the left of the steering
wheel.
O: Turns off the automatic headlamps and
Daytime Running Lamps (DRL). Turn the
headlamp control to
Oagain to turn the
automatic headlamps or DRL back on.
For vehicles first sold in Canada, off will only
work when the vehicle is in P (Park). AUTO :
Automatically turns on the
headlamps, parking lamps, taillamps,
instrument panel lights, roof marker lamps
(if equipped), front/rear sidemarker lamps,
and license plate lamps.
;: Turns on the parking lamps including
all lamps, except the headlamps and fog
lamps, if equipped.
For some trim levels and series of trucks
first sold in Canada, the headlamps may
turn on with the parking lamps.
2: Turns on the headlamps together with
the parking lamps, taillamps, instrument
panel lights, roof marker lamps (if
equipped), front/rear sidemarker lamps, and
license plate lamps.
When the headlamps are turned on while
the vehicle is on, the headlamps turn off
automatically 10 minutes after the ignition
is turned off. When the headlamps are
turned on while the vehicle is off, the
headlamps will stay on for 10 minutes
before turning off to prevent the battery
from being drained. Turn the headlamp
control off and then back to the headlamp
on position to make the headlamps stay on

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/6/20
Lighting 141
.The vehicle is loaded such that the front
end points upward, causing the light
sensor to aim high and not detect
headlamps and taillamps.
.Driving on winding or hilly roads.
The automatic high-beam headlamps may
need to be disabled if any of the above
conditions exist.
Exterior Lamps Off Reminder
A reminder chime sounds when the
headlamps or parking lamps are manually
turned on, the ignition is off, and a door is
open. To disable the chime, turn the
lamps off.
Headlamp High/Low-Beam
Changer
Push the turn signal lever toward the
instrument panel to change the headlamps
from low to high beam.
Pull or push the turn signal lever to return
to low-beam headlamps.
When the high-beam headlamps are on, this
indicator light on the instrument cluster will
also be on.
Flash-to-Pass
This feature lets you use the high-beam
headlamps to signal a driver in front of you
that you want to pass. It works even if the
headlamps are in the automatic position.
To use it, pull the turn signal lever toward
you, then release it.
If the headlamps are in the automatic
position or on low beam, the high-beam
headlamps will turn on. Depending on the
type of headlamp, they will either turn off
after a short duration or stay on as long as
you hold the lever toward you. The
high-beam indicator on the instrument
cluster will come on. Release the lever to
return to normal operation.
Daytime Running Lamps (DRL)
DRL can make it easier for others to see the
front of the vehicle during the day. Fully
functional DRL are required on all vehicles
first sold in Canada.
The DRL system comes on when the
following conditions are met:
.The ignition is on.
.The exterior lamp control is in AUTO.
.The transmission is not in P (Park).
.The light sensor determines it is daytime.
When the DRL system is on, only the DRL
are on. The taillamps, sidemarker lamps,
instrument panel lights, and other lamps
will not be on.
When it begins to get dark, the automatic
headlamp system switches from DRL to the
headlamps.
To turn off the DRL, turn the exterior lamp
control to
Oand then release. For vehicles
first sold in Canada, off will only work when
the vehicle is parked.

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
454 Index
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
LightingEntry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Illumination Control . . . . . . . . . . . . . . . . . . . 145
LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Lights Airbag Readiness . . . . . . . . . . . . . . . . . . . . . . . 114
Antilock Brake System (ABS)Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Brake System Warning . . . . . . . . . . . . . . . . . 117
Charging System . . . . . . . . . . . . . . . . . . . . . . . 115
Check Engine (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . 123
Door Ajar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Driver Mode Control . . . . . . . . . . . . . . . . . . . . 121
Electric Parking Brake . . . . . . . . . . . . . . . . . . . 117
Electronic Stability Control (ESC), Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Engine Coolant Temperature Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Engine Oil Pressure . . . . . . . . . . . . . . . . . . . . 122
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Four-Wheel-Drive . . . . . . . . . . . . . . . . . . . . . . . 118
Front Fog Lamp . . . . . . . . . . . . . . . . . . . . . . . . 123
High-Beam On . . . . . . . . . . . . . . . . . . . . . . . . . 123 Lights (cont'd)
High/Low Beam Changer . . . . . . . . . . . . . . . 141
Hill Descent Control . . . . . . . . . . . . . . . . . . . . 119
Lane Keep Assist . . . . . . . . . . . . . . . . . . . . . . . . 119
Low Fuel Warning . . . . . . . . . . . . . . . . . . . . . 122
Seat Belt Reminders . . . . . . . . . . . . . . . . . . . . 113
Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Service Electric Parking Brake . . . . . . . . . . . 118
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Tow/Haul Mode . . . . . . . . . . . . . . . . . . . . . . . . 119
Traction Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Limited-Slip Differential . . . . . . . . . . . . . . . . . . 254
Lock
Steering Column . . . . . . . . . . . . . . . . . . . . . . . . 32
Locking Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . 254
Locks Automatic Door . . . . . . . . . . . . . . . . . . . . . . . . . 22
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 22
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Lockout Protection . . . . . . . . . . . . . . . . . . . . . . 22
Power Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Low Fuel Warning Light . . . . . . . . . . . . . . . . . . 122
Lower Anchors and Tethers for Children (LATCH System) . . . . . . . . . . . . . . . . .77
Lumbar Adjustment . . . . . . . . . . . . . . . . . . . . . . . 48 Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
Maintenance and Care Additional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Maintenance Schedule . . . . . . . . . . . . . . . . . . . 409 Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
Transfer Case . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Malfunction Indicator Lamp . . . . . . . . . . . . . . . 115
Manual Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . .241
Manual Windows . . . . . . . . . . . . . . . . . . . . . . . . . .41
Map Data Updates . . . . . . . . . . . . . . . . . . . . . . . . 175
Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Media
Avoiding Untrusted Devices . . . . . . . . . . . . 158
Memory Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Messages Engine Power . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Vehicle Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Mirror Rear Camera . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Mirrors Automatic Dimming . . . . . . . . . . . . . . . . . . . . 37
Automatic Dimming Rearview . . . . . . . . . . 38
Blind Spot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37