2023 GMC SIERRA lights

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Lighting 141
.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 vehicle is turned 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 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 turn 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.
Automatic Headlamp System
When the exterior lamp control is set to
AUTO and it is dark enough outside, the
headlamps come on automatically.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
142 Lighting
There is a light sensor on top of the
instrument panel. Do not cover the sensor,
otherwise the headlamps will come on when
they are not needed.
The system may also turn on the headlamps
when driving through a parking garage or
tunnel.
If the vehicle is started in a dark garage, the
automatic headlamp system comes on
immediately. If it is light outside when the
vehicle leaves the garage, there is a slight
delay before the automatic headlamp
system changes to the Daytime Running
Lamps (DRL). During that delay, the
instrument cluster may not be as bright as
usual. Make sure the instrument panelillumination control is in the full bright
position. See
Instrument Panel Illumination
Control 0145.
When it is bright enough outside, the
headlamps will turn off or may change
to DRL.
The automatic headlamp system turns off
when the exterior lamp control is turned to
Oor the ignition is off.
Lights On with Wipers
If the windshield wipers are activated in
daylight with the engine on, and the
exterior lamp control is in AUTO, the
headlamps, parking lamps, and other
exterior lamps come on. The transition time
for the lamps coming on varies based on
wiper speed. When the wipers are not
operating, these lamps turn off. Move the
exterior lamp control to
Oor;to disable
this feature.
Hazard Warning Flashers
|: Press this button to make the front
and rear turn signal lamps flash on and off.
Press again to turn the flashers off.
When the hazard warning flashers are on,
the vehicle's turn signals will not work.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
144 Lighting
Some localities have laws that require the
headlamps to be on with the fog lamps.
Task Lighting
If equipped, task lighting projects light from
the outside mirrors away from the vehicle.
While the vehicle is parked, press
Kto
select one of the following options:
.Left and Right Task Lights Illuminated
.Left Task Light Illuminated
.Right Task Light Illuminated
.Left and Right Task Lights Off
If the vehicle leaves a parked position, the
lights will immediately turn off. If the vehicle is off, the lights will stay on
for approximately 10 minutes.
If any Task lights are on, if the button has
not been pressed after approximately
5 seconds, pressing it again will turn off all
Task Lights.
Auxiliary Roof-Mounted Lamp
If equipped, this button includes wiring
provisions for a dealer or a qualified service
center to install an auxiliary roof lamp.
For information on roof-mounted emergency
lamp installation, see www.gmupfitter.com
or contact your dealer.
If the vehicle has this button, the vehicle
may have the snow plow prep package. See
Add-On Electrical Equipment
0297.
Exterior Cargo Lamps
The cargo lamps provide more light in the
cargo area or on the sides of the vehicle,
if needed. The lamps inside the pickup box,
in the tailgate handle, for the hitch, and/or
the cargo mirror lamps also turn on,
if equipped.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Lighting 145
If the vehicle is in P (Park), R (Reverse),
or N (Neutral) the Cargo Lamp Switch causes
the lights to cycle through the following
states for each button press:
Initial Press
‐Center High Mounted Stop Lamp
(CHMSL)/Cargo Bed Lights –On
‐ Cargo Mirror Lights –On
‐ Cargo Switch Indicator (if equipped) –On
Next Press (if within 5 seconds of the
previous button press)
‐ CHMSL/Cargo Bed Lights –On
‐ Cargo Mirror Lights –Off
‐ Cargo Switch Indicator (if equipped) –On
Next Press
‐ CHMSL/Cargo Bed Lights –Off
‐ Cargo Mirror Lights –Off
‐ Cargo Switch Indicator (if equipped) –Off
Become familiar with and follow all state
and local laws that apply to cargo lamp
operation.Interior Lighting
Instrument Panel Illumination
Control
This feature adjusts the brightness of all
illuminated controls. The instrument panel
illumination control is next to the exterior
lamp control.
D: PressD− to dim or +Dto brighten
the lights.
This feature is functional at night, or when
the headlamps or parking lamps are on.
Dome Lamps
The dome lamp controls are in the overhead
console.
The dome lamps come on when any door is
opened,
Kon the remote key is pressed,
or when the vehicle is turned off.
To operate, press the following buttons:
jOFF : Press to turn off the dome
lamps. An indicator light on the button will
turn on when the dome lamp override is
activated. Press
jOFF again to
deactivate this feature and the indicator
light will turn off.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
146 Lighting
+ON/OFF :Press to turn the dome lamps
on or off manually.
Reading Lamps
There are reading lamps on the overhead
console and over the rear seats. These lamps
come on when any door is opened,
Kon
the remote key is pressed, or when the
vehicle is turned off.
Front Reading Lamps
The front reading lamps are in the overhead
console.
Press the lamp lenses to turn the front
reading lamps on or off. Rear Reading Lamps
The rear reading lamps are over the rear
seats.
Press the lamp lens to turn the rear reading
lamps on or off.
Lighting Features
Entry Lighting
The interior lamps turn on when pressingK
on the remote key or opening any doors,
and the dome lamp control is in the door
position.
Some exterior lamps also turn on when
pressing
Kon the remote key or opening
any doors. Low-Beam lamps will only turn
on briefly at night, or in areas with limited
lighting. All lamps will gradually fade out after about
30 seconds.
Entry lighting can be disabled manually by
closing all doors, pressing
Qon the remote
key, or starting the vehicle.
This feature can be changed. On the
infotainment home page, select the Settings
icon
TVehicleTVehicle Locator Lights.
Exit Lighting
Some exterior lamps and interior lamps turn
on when the driver door is opened after the
vehicle is turned off.
The exterior and interior lamps remain on
for a set amount of time, then automatically
turn off.
The interior lights turn on when the vehicle
is turned off.
The exterior lamps turn off immediately by
turning the exterior lamp control off.
This feature can be changed. On the
infotainment home screen, select the
Settings icon
TVehicleTExit Lighting.

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
Driving and Operating 257
vehicle personalization. The On with Towbar
setting allows Park Assist to work properly
with a trailer hitch. Some larger trailer
hitches may not be compatible.
To view available settings for this feature,
touch the Settings icon on the infotainment
home page. Select“Vehicle”to display the
list of available options and select “Collision/
Detection Systems”.
Turn off Park Assist when towing a trailer.
To turn the “Rear Camera Park Assist
Symbols” on or off, touch the Settings icon
on the infotainment home page. Select
“Vehicle” to display the list of available
options and select “Collision/Detection
Systems”.
Rear Cross Traffic Alert (RCTA)
System
If equipped, Rear Cross Traffic Alert (RCTA)
displays a red warning triangle with a left
or right pointing arrow on the infotainment
display to warn of traffic coming from the
left or right. This system detects objects
coming from up to 20 m (65 ft) from the left
or right side of the vehicle. When an object
is detected, either three beeps sound from
the left or right or three Safety Alert Seat pulses occur on the left or right side,
depending on the direction of the detected
vehicle.
Driving With a Trailer
Use caution while backing up when towing
a trailer. The RCTA feature is automatically
disabled when a trailer is attached to the
vehicle.
Turning the Features On or Off
The
Xbutton on the center stack is used
to turn on or off the Rear Park Assist (RPA),
and Backing Warning and Reverse Automatic
Braking (RAB) systems at the same time.
The indicator light next to the button comes
on when the features are on and turns off
when the features have been disabled.
Turn off RPA, RCTA, and RAB when towing a
trailer.
RCTA can be turned on or off using the
infotainment system. To view available
settings from the infotainment screen, touch
Settings > Vehicle > Collision/Detection
Systems.
Assistance Systems for Driving
If equipped, when driving the vehicle in a
forward gear, Forward Collision Alert (FCA),
Lane Keep Assist (LKA), Lane Departure
Warning (LDW), Side Blind Zone Alert (SBZA),
Lane Change Alert (LCA), and/or the
Automatic Emergency Braking (AEB) can help
to avoid a crash or reduce crash damage.
Forward Collision Alert (FCA)
System
If equipped, the FCA system may help to
avoid or reduce the harm caused by
front-end crashes. When approaching a
vehicle ahead too quickly, FCA provides a
red flashing alert on the windshield and
rapidly beeps or pulses the driver seat. FCA
also lights an amber visual alert if following
another vehicle much too closely.
FCA detects vehicles within a distance of
approximately 60 m (197 ft) and operates at
speeds above 8 km/h (5 mph).

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 261
part of the Lane Change Alert (LCA) system,
read the entire LCA section before using this
feature.
Lane Change Alert (LCA)
If equipped, the LCA system is a
lane-changing aid that assists drivers with
avoiding lane change crashes that occur with
moving vehicles in the side blind zone (or
spot) areas or with vehicles rapidly
approaching these areas from behind. The
LCA warning display will light up in the
corresponding outside side mirror and will
flash if the turn signal is on.
{Warning
LCA does not alert the driver to vehicles
outside of the system detection zones,
pedestrians, bicyclists, or animals. It may
not provide alerts when changing lanes
under all driving conditions. Failure to use
proper care when changing lanes may
result in injury, death, or vehicle damage.
Before making a lane change, always
check mirrors, glance over your shoulder,
and use the turn signals.LCA Detection Zones
1. SBZA Detection Zone
2. LCA Detection Zone
The LCA sensor covers a zone of
approximately one lane over from both
sides of the vehicle, or 3.5 m (11 ft). The
height of the zone is approximately between
0.5 m (1.5 ft) and 2 m (6 ft) off the ground.
The Side Blind Zone Alert (SBZA) warning
area starts at approximately the middle of
the vehicle and goes back 5 m (16 ft). Drivers
are also warned of vehicles rapidly
approaching from up to 70 m (230 ft) behind
the vehicle.
How the System Works
The LCA symbol lights up in the side mirrors
when the system detects a moving vehicle
in the next lane over that is in the side blind zone or rapidly approaching that zone
from behind. A lit LCA symbol indicates it
may be unsafe to change lanes. Before
making a lane change, check the LCA
display, check mirrors, glance over your
shoulder, and use the turn signals.
Left Side Mirror
DisplayRight Side Mirror Display
When the vehicle is started, both outside
mirror LCA displays will briefly come on to
indicate the system is operating. When the
vehicle is in a forward gear, the left or right
side mirror display will light up if a moving
vehicle is detected in the next lane over in
that blind zone or rapidly approaching that
zone. If the turn signal is activated in the
same direction as a detected vehicle, this
display will flash as an extra warning not to
change lanes.
LCA can be disabled through vehicle settings.
When you disable LCA, SBZA is also disabled.
To view available settings from the