light GMC SIERRA 2021 Repair Manual

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/6/20
Lighting 143
Turn and Lane-Change Signals
An arrow on the instrument cluster flashes
in the direction of the turn or lane change.
Move the turn signal lever all the way up or
down to signal a turn.
Partially raise or lower the lever for less
than one second until the arrow starts to
flash to signal a lane change. This causes
the turn signals to automatically flash three
times. It will flash six times if Tow/Haul
Mode is active. Holding the turn signal lever
for more than one second will cause the
turn signals to flash until the lever is
released.The lever returns to its starting position
whenever it is released.
If after signaling a turn or a lane change the
arrows flash rapidly or do not come on, a
signal bulb could be burned out. If equipped
with LED turn signals, see your dealer.
Replace any burned out bulbs. If a bulb is
not burned out, check the fuse. See
Fuses
and Circuit Breakers 0353.
Turn Signal On Chime
If the turn signal is left on for more than
1.2 km (0.75 mi), a chime sounds at each
flash of the turn signal. A message may
appear in the Driver Information Center
(DIC). See Vehicle Messages 0130. To turn
the chime and message off, move the turn
signal lever to the off position.
Fog Lamps
If equipped, the fog lamp control is near the
exterior lamp control to the left of the
steering column.
The ignition must be on for the fog lamps
to come on.
#: Press to turn the fog lamps on or off.
A light will come on in the instrument
cluster.
When the fog lamps are turned on, the
parking lamps automatically turn on.
When the headlamps are changed to high
beam, the fog lamps also go off. When the
high-beam headlamps are turned off, the fog
lamps will come on again.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/6/20
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
0318.
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 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/6/20
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:
- CHMSL/Cargo Bed Lights - On
- Cargo Mirror Lights - On
- Cargo Switch Indicator (if equipped) - On
- Next Press: (if with in 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 brighten orD− to
dim 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.
To operate, press the following buttons:
jOFF : Press to turn off the dome
lamps when a door is open. An indicator
light on the button will turn on when the
dome lamp override is activated. Press
j
OFF again to deactivate this feature and the
indicator light will turn off. The dome lamps
will come on when any door is opened,
K
on the remote key is pressed, or when the
ignition is switched off.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/6/20
146 Lighting
+ON/OFF :Press to turn the dome lamps
on manually. Press again to turn the dome
lamps off.
Reading Lamps
There are reading lamps on the overhead
console and over the rear seats. These lamps
come on when any door is opened.
To operate, the ignition must be on, or in
ACC/ACCESSORY, or using Retained Accessory
Power (RAP).
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
Some exterior lamps turn on briefly at
night, or in areas with limited lighting,
when
Kis pressed on the remote key. After
about 30 seconds the exterior lamps turn
off. When any door is opened or the remote
unlock is pressed, all interior lights turn on
and then interior lamps dim to off after
20 seconds. The entry lighting feature for exterior
lighting can be changed. See
“Vehicle
Locator Lights” underVehicle Personalization
0 131.
Exit Lighting
Some exterior lamps come on at night, or in
areas with limited lighting, when the driver
door is opened after the ignition is turned
off. The dome lamp comes on when any
door is opened or after the ignition is
turned off. The exterior lamps and dome
lamp remain on after the door is closed for
a set amount of time, then automatically
turn off.
The exterior lamps turn off immediately by
turning the exterior lamp control off.
The exit lighting for exterior lights can be
changed. See Vehicle Personalization 0131.
Battery Load Management
The vehicle has Electric Power Management
(EPM), which estimates the battery's
temperature and state of charge. It then
adjusts the voltage for best performance
and extended life of the battery.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/6/20
Lighting 147
When the battery's state of charge is low,
the voltage is raised slightly to quickly bring
the charge back up. When the state of
charge is high, the voltage is lowered
slightly to prevent overcharging. The
voltmeter gauge or the voltage display on
the Driver Information Center (DIC),
if equipped, may show the voltage moving
up or down. This is normal. If there is a
problem, an alert will be displayed.
The battery can be discharged at idle if the
electrical loads are very high. This is true for
all vehicles. This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all the power that
is needed for very high electrical loads.
A high electrical load occurs when several of
the following are on, such as: headlamps,
high beams, fog lamps, rear window
defogger, climate control fan at high speed,
heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory
power outlets.EPM works to prevent excessive discharge of
the battery. It does this by balancing the
generator's output and the vehicle's
electrical needs. It can increase engine idle
speed to generate more power, whenever
needed. It can temporarily reduce the power
demands of some accessories.
Normally, these actions occur in steps or
levels, without being noticeable. In rare
cases at the highest levels of corrective
action, this action may be noticeable to the
driver. If so, a DIC message might be
displayed and it is recommended that the
driver reduce the electrical loads as much as
possible.
Battery Power Protection
This feature shuts off the dome and reading
lamps, if they are left on for more than
10 minutes after the ignition is turned off.
The cargo lamp shuts off after 20 minutes.
This prevents the battery from
running down.
Exterior Lighting Battery Saver
The exterior lamps turn off about 10 minutes
after the ignition is turned off, if the parking
lamps or headlamps have been manually
left on. This protects against draining the
battery. To restart the 10-minute timer, turn
the exterior lamp control to the
Oposition
and then back to the
;or2position.
To keep the lamps on for more than
10 minutes, the ignition must be on or in
ACC/ACCESSORY.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
150 Infotainment System
3.{
.Press to go to the Home Page. See
“Home Page”later in this section.
.Press to exit Android Auto or Apple
CarPlay. To enter back into Android
Auto or Apple CarPlay, press and
hold. SeeApple CarPlay and
Android Auto 0185.
4.6
.Radio: Press and release to go to
the next station or channel. Press
and hold to fast seek the next
strongest station or channel.
.USB/Bluetooth: Press to seek the
next track. Press and hold to fast
forward through a track. Release to
return to playing speed. See USB
Port 0158 or
Bluetooth Audio 0162.
5.oBACK
.Press to return to the previous
display in a menu.
6.V
.Turn to highlight a feature. Press
to activate the highlighted feature.
1.{(Home Page)
.Press to go to the Home Page. See
“Home Page” later in this section.
.Press to exit Android Auto or Apple
CarPlay. To enter back into Android
Auto or Apple CarPlay, press and
hold. SeeApple CarPlay and
Android Auto 0185.
2.7
.Radio: Press and release to go to
the previous station or channel.
Press and hold to fast seek the
next strongest previous station or
channel. See AM-FM Radio 0155.
.USB/Bluetooth: Press to seek to
the beginning of the current or
previous track. Press and hold to
quickly reverse through a track.
Release to return to playing speed.
See USB Port 0158 or
Bluetooth Audio 0162.
3.O(Power)
.Press to turn the power on.
.Press and hold to turn the
power off.
.Press to mute/unmute the system
when on.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Infotainment System 153
Availability of apps and connectivity varies
by vehicle, conditions, and location. Data
plan rates apply. Features are subject to
change. For more information, see
www.my.gmc.com/learn.
OnStar Services
If equipped, touch the OnStar Services icon
to display the OnStar Services and Account
pages. SeeOnStar Overview 0440 and
OnStar System 0162.
Camera
If equipped, touch the Camera icon to access
the camera application. See Assistance
Systems for Parking or Backing 0266.
Shortcut Tray
The shortcut tray is near the bottom of the
display. It shows up to four applications.
Infotainment Display Features
Infotainment display features show on the
display when available. When a feature is
unavailable, it may gray out. When a
feature is touched, it may highlight.
Haptic Feedback
If equipped, haptic feedback is a pulse that
occurs when an icon or option is touched on
the display or when controls on the center
stack are pressed.
Infotainment Gestures
Use the following finger gestures to control
the infotainment system.
Touch/Tap
Touch/tap is used to select an icon or
option, activate an application, or change
the location inside a map. Touch and Hold
Touch and hold can be used to start another
gesture, or to move or delete an application.
Drag
Drag is used to move applications on the
Home Page, or to pan the map. To drag the
item, it must be held and moved along the
display to the new location. This can be

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
156 Infotainment System
The keypad will gray out entries that do not
contribute to a valid frequency and will
automatically place a decimal point within
the frequency number.
Touch (X) to delete one number at a time.
Touch and hold (X) to delete all numbers.
A valid AM or FM station will automatically
tune to the new frequency but not close the
Direct Tune display. When listening to SXM
(if equipped), touch Go after entering the
channel. Touch the Back icon on the
infotainment display or touch
zto exit out
of Direct Tune.
The tune arrows on the right side of the
Direct Tune display will tune through the
complete station or channel list one station
step at a time per touch. A touch and hold
advances through stations or channels
quickly.
If equipped, HD Radio multicast stations
cannot be tuned directly through the Direct
Tune feature. Only the analog or
HD1 station can use that feature. Use the
display arrows to adjust to the multicast
stations.
AM, FM, and SXM Categories
From the AM stations, if equipped with HD
Radio, FM, or SXM (if equipped) display,
touch Categories at the top of the Browse
menu to access the categories list. The list
contains names associated with the AM or
FM stations, or SXM channels. Touch a
category name to display a list of stations
or channels for that category. Touching a
station or channel from the list will tune the
radio to that station or channel.
Storing Radio Station Presets
Favorites show in the area at the top of the
display.
AM, FM, SXM (if equipped), and HD Radio
Stations (if equipped) : Press and hold a
preset to store the current station or
channel as a favorite. Touch a saved favorite
to recall a favorite station or channel. Favorites can also be stored by touching
H
in a station or channel list. This will
highlight indicating that it is now saved as a
favorite.
The number of favorites displayed is
automatically adjusted by default, but can
be manually adjusted in Settings in the
System tab under Favorites and then Set
Number of Audio Favorites. It can also be
adjusted in Settings in the Apps tab under
Audio and then Set Number of Audio
Favorites.
HD Radio Technology
If equipped, HD Radio is a free service with
features such as digital quality sound, more
stations available on a single frequency such
as HD2 and HD3, and display information
such as artist and song title.
From the Now Playing display, touch the HD
Radio icon to turn HD on or off.
Station Access
To access HD Radio stations:
1. Tune the radio to the station. If HD Radio is turned on and the station is
broadcasting in HD Radio, the radio will
automatically tune to the HD version of
the current channel (HD1) after several

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
158 Infotainment System
by model and require a complete working
electrical system, cell reception, and GPS
signal. An active connected plan is required.
Reference the SiriusXM user guide for use
and subscription information.
Radio Reception
Unplug electronic devices from the accessory
power outlets if there is interference or
static in the radio.
FM
FM signals only reach about 16 to 65 km (10
to 40 mi). Although the radio has a built-in
electronic circuit that automatically works to
reduce interference, some static can occur,
especially around tall buildings or hills,
causing the sound to fade in and out.
AM
The range for most AM stations is greater
than for FM, especially at night. The longer
range can cause station frequencies to
interfere with each other. Static can also
occur when things like storms and power
lines interfere with radio reception. When
this happens, try reducing the treble on the
radio.
SiriusXM Satellite Radio Service
If equipped, SiriusXM Satellite Radio Service
provides digital radio reception. Tall
buildings or hills can interfere with satellite
radio signals, causing the sound to fade in
and out. In addition, traveling or standing
under heavy foliage, bridges, garages,
or tunnels may cause loss of the SiriusXM
signal for a period of time. Some cellular
services may interfere with SXM reception
causing loss of signal.
Mobile Device Usage
Mobile device usage, such as making or
receiving calls, charging, or just having the
mobile device on may cause static
interference in the radio. Unplug the mobile
device or turn it off if this happens.
Fixed Mast Antenna
The fixed mast antenna will go through
most car washes as long as it is securely
attached. If the antenna becomes slightly
bent, straighten it out by hand. If it is badly
bent, replace it.
Occasionally check that the antenna is tight
at the base. If tightening is required, protect
the paint from damage.
Multi-Band Antenna
The roof antenna is for SiriusXM Satellite
Radio, OnStar, and GPS (Global Positioning
System), depending on the equipped
options. Keep clear of obstructions for clear
reception. If the vehicle has a sunroof, and it
is open, reception can also be affected.
Audio Players
Avoiding Untrusted Media Devices
When using media devices such as SD cards,
USB devices, and mobile devices, consider
the source. Untrusted media devices could
contain files that affect system operation or
performance. Avoid use if the content or
origin cannot be trusted.
USB Port
This vehicle is equipped with two USB ports
in the center console under the armrest and
another two in the center stack. These ports
are for data and charging.
There may also be two USB ports for
charging only at the rear of the center
console.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Infotainment System 165
.About
To exit a list, touch
zin the top right
corner to return to the main map view.
Make sure to set up preferences before
setting a destination and starting active
guidance.
Map Preferences
Touch to choose between basic map feature
configurations:
Map Colors
.Auto –Touch to automatically change
modes based on lighting conditions.
.Day (Light)
.Night (Dark)
3D Landmark (Default is On) : Touch On or
Off. When turned on, the system will
display all 3D Landmarks on the map
depending on the zoom level.
3D Building (Default is Off) : Touch On or
Off. When turned on, the system will
display all of the possible 3D building shapes
on the map depending on the zoom level.
Show Terrain in 3D (Default is Off) :
If equipped, touch On or Off. When turned
on, the system will display terrain
information on the map in 3D view. Auto-Zoom (Default is On) :
Touch On or
Off. When turned on, the system will
automatically adjust the zoom level when
the vehicle is approaching a turn. After the
turn is completed, the system automatically
brings the zoom back to the originally set
level. If the vehicle is approaching a turn
with the next turn occurring shortly after,
the Auto-Zoom will remain on until both
turns are completed.
Route Preferences
Touch to access the Route Preferences. The
choices are:
.Preferred Route –Choose from two
different route options: Fastest or
Eco-Friendly.
‐ Fastest would be the route with the
shortest drive time.
‐ Eco-Friendly would be the most
fuel-efficient route.
.Avoid on Current Route –Choose any of
the road features to avoid while on route:
‐ Highways
‐ Unpaved Roads
‐ Ferries
‐ Carpool Lanes
‐ Toll Roads ‐
Tunnels
‐ Country Borders
Navigation Voice Control
Touch to access the voice control setting
display.
.Navigation Volume –To adjust the
volume level, touch the up and down
arrows. If the voice guidance prompt is
being heard, volume can also be adjusted
using the knob on the center stack or the
volume switch on the steering wheel.
.Navigation Voice Prompt Level during a
Call. Options available are:
‐ Full Prompt (Selected by default)
‐ Tone Only
‐ None
Traffic Events (If Equipped)
This feature provides a list of events that
are on the route or nearby. Touch
Aand
then select Traffic Events. An OnStar
connected Navigation service plan is
required.