
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
176 Lighting
Lighting Exterior Lighting Exterior Lamp Controls . . . . . . . 176
Exterior Lamps Off
Reminder . . . . . . . . . . . . . . . . . . . 178
Headlamp High/Low-Beam
Changer . . . . . . . . . . . . . . . . . . . . 179
Flash-to-Pass . . . . . . . . . . . . . . . . 179
Daytime Running
Lamps (DRL) . . . . . . . . . . . . . . . 179
Automatic Headlamp
System . . . . . . . . . . . . . . . . . . . . . . 179
Hazard Warning Flashers . . . . . 180
Turn and Lane-Change
Signals . . . . . . . . . . . . . . . . . . . . . . 181
Fog Lamps . . . . . . . . . . . . . . . . . . . 181
Auxiliary
Roof-Mounted Lamp . . . . . . . . 182
Interior Lighting Instrument Panel Illumination
Control . . . . . . . . . . . . . . . . . . . . . . 182
Cargo Lamp . . . . . . . . . . . . . . . . . . 183
Dome Lamps . . . . . . . . . . . . . . . . . 183
Reading Lamps . . . . . . . . . . . . . . 183 Lighting Features Entry Lighting . . . . . . . . . . . . . . . . 184
Exit Lighting . . . . . . . . . . . . . . . . . . 184
Battery Load Management . . . 184
Battery Power Protection . . . . . 185
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . 185
Exterior Lighting Exterior Lamp Controls
The exterior lamp control is on the
instrument panel to the left of the
steering wheel.
O (Off) : Turns off the automatic
headlamps and Daytime Running
Lamps (DRL). Turn the headlamp
control to the off position again 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).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Lighting 177AUTO (Automatic) : Automatically
turns on the headlamps, parking
lamps, taillamps, instrument panel
lights, roof marker lamps (if
equipped), front/rear sidemarker
lamps, and license plate lamps.
When the vehicle is turned off and
the headlamps are in AUTO, the
headlamps turn off. When the key is
removed, they automatically turn on
for a set time. The time of the delay
can be changed using the DIC.
See Driver Information Center (DIC)
(Uplevel and Denali Cluster) 0 160
or Driver Information Center (DIC)
(Base Level Cluster) 0 158 .
; (Parking Lamps) : Turns on the
parking lamps including all lamps,
except the headlamps.
For some trim levels and series of
trucks first sold in Canada, the
headlamps will turn on with the
parking lamps.
2 (Headlamps) : Turns on the
headlamps together with the parking
lamps and instrument panel lights. 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 for an additional 10 minutes.
To keep the lamps on for more than
10 minutes, the ignition must be in
the ACC/ACCESSORY or ON/RUN
position.
# (Fog Lamps) (If Equipped) :
Turns on the fog lamps. See Fog
Lamps 0 181 .
IntelliBeam ®
System
If equipped, this system turns the
vehicle's high-beam headlamps on
and off according to surrounding
traffic conditions. The system turns the high-beam
headlamps on when it is dark
enough and there is no other traffic
present.
This light comes on in the
instrument cluster when the
IntelliBeam system is enabled.
Turning On and Enabling
IntelliBeam
To enable the IntelliBeam system,
with the turn signal lever in the
neutral position, turn the exterior
lamp control to AUTO. The blue
high-beam on light appears on the
instrument cluster when the high
beams are on.
Driving with IntelliBeam
The system only activates the high
beams when driving over 40 km/h
(25 mph).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
182 Lighting Some localities have laws that
require the headlamps to be on with
the fog lamps.
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.
This button is on the overhead
console.
When the wiring is connected to an
auxiliary roof-mounted lamp,
pressing the bottom of the button
will activate the lamp and illuminate
an indicator light at the bottom of this button. Pressing the top of the
button will turn off the roof-mounted
lamp and indicator.
The emergency roof lamp circuit is
fused at 30 amps, so the total
current draw of the attached lamps
should be less than this value. The
attachment points for the roof lamp
circuits are two blunt cut wires
above the overhead console: a dark
green with blue stripe switched
power wire and a black ground wire.
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 0 336 .Interior Lighting Instrument Panel
Illumination Control
This feature controls the brightness
of the steering wheel and instrument
panel lights. The instrument panel
illumination control is next to the
exterior lamp control.
D : Move the thumbwheel up or
down to brighten or dim the lights.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
194 Infotainment System 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. Cell Phone Usage Cell phone usage, such as making
or receiving phone calls, charging,
or just having the phone on may
cause static interference in the
radio. Unplug the phone 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 multi-band antenna is on the
roof of the vehicle. The antenna is
used for OnStar, the SiriusXM
Satellite Radio Service System, and
GPS (Global Positioning System),
if the vehicle has these features.
Keep the antenna clear of
obstructions for clear reception.
If the vehicle has a sunroof, and it is
open, reception can also be
affected.
Items on the roof of the vehicle can
interfere with the performance of the
radio system and OnStar (if
equipped). Make sure the
multi-band antenna is not
obstructed.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
240 Driving and Operating To gain more ground clearance if
needed, it may be necessary to
remove the front fascia lower air
dam, if equipped. However, driving
without the air dam reduces fuel
economy.
CautionOperating the vehicle for
extended periods without the front
fascia lower air dam installed can
cause improper airflow to the
engine. Reattach the front fascia
air dam after off-road driving.
Loading the Vehicle for
Off-Road Driving
{ Warning
.
Unsecured cargo on the
load floor can be tossed
about when driving over
rough terrain. You or your
(Continued) Warning (Continued) passengers can be struck
by flying objects. Secure the
cargo properly.
.
Keep cargo in the cargo
area as far forward and as
low as possible. The
heaviest things should be
on the floor, forward of the
rear axle.
.
Heavy loads on the roof
raise the vehicle's center of
gravity, making it more likely
to roll over. You can be
seriously or fatally injured if
the vehicle rolls over. Put
heavy loads inside the
cargo area, not on the roof.
For more information about loading
the vehicle, see Vehicle Load Limits
0 248 and Tires 0 389 . Environmental Concerns .
Always use established trails,
roads, and areas that have been
set aside for public off-road
recreational driving and obey all
posted regulations.
.
Do not damage shrubs, flowers,
trees, or grasses or disturb
wildlife.
.
Do not park over things that
burn. See Parking over Things
That Burn 0 264 .
Driving on Hills Driving safely on hills requires good
judgment and an understanding of
what the vehicle can and cannot do.
{ Warning
Many hills are simply too steep
for any vehicle. Driving up hills
can cause the vehicle to stall.
Driving down hills can cause loss
of control. Driving across hills can
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
260 Driving and Operating .
Pressing the accelerator more
than one-quarter of the
way down.
.
Turning the ignition off.
Retained Accessory
Power (RAP) The following vehicle accessories
can be used for up to 10 minutes
after the engine is turned off:
.
Audio System
.
Power Windows
.
OnStar System (if equipped)
.
Sunroof (if equipped)
These features work when the key
is in ON/RUN or ACC/
ACCESSORY. Once the key is
turned from ON/RUN to LOCK/OFF,
the windows and sunroof continue
to work up to 10 minutes or until any
door is opened. The radio continues
to work for up to 10 minutes or until
the driver door is opened. Accessory Power Outlets (APOs)
The vehicle may have Accessory
Power Outlets (APOs) in several
locations. See Power Outlets 0 133 .
The APOs in the console or center
seat position are powered by
Retained Accessory Power (RAP).
They will continue to work for up to
10 minutes after the key is turned
from ON/RUN to LOCK/OFF, or until
the driver door is opened.
The APOs on the center stack come
from the factory powered directly
from the vehicle battery, and supply
accessory power at all times,
regardless of ignition key position.
If electronic items are left plugged
into these APOs for long periods of
time with the vehicle off, the vehicle
battery could be drained. The
vehicle may not start if the battery is
allowed to drain for an extended
period of time. Engine Coolant Heater The engine heater can provide
easier starting and better fuel
economy during engine warm-up in
cold weather conditions at or below
− 18 °C (0 °F). Vehicles with an
engine heater should be plugged in
at least four hours before starting.
An internal thermostat in the
plug-end of the cord may exist,
which will prevent engine coolant
heater operation at temperatures
above − 18 °C (0 °F).
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
{ Warning
Do not plug in the engine block
heater while the vehicle is parked
in a garage or under a carport.
Property damage or personal
injury may result. Always park the
vehicle in a clear open area away
from buildings or structures.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 261To Use the Engine Coolant
Heater 1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord. The cord is
secured to the driver side
fender with a clip, next to the
engine compartment fuse
block. Carefully remove the
wire tie that bundles the
electrical plug. Do not cut the
electrical cord.
Check the heater cord for
damage. If it is damaged, do
not use it. See your dealer for
a replacement. Inspect the
cord for damage yearly.
3. Plug the cord into a normal,
grounded 110-volt AC outlet. { WarningImproper use of the heater cord
or an extension cord can damage
the cord and may result in
overheating and fire.
.
Plug the cord into a
three-prong electrical utility
receptacle that is protected
by a ground fault detection
function. An ungrounded
outlet could cause an
electric shock.
.
Use a weatherproof,
heavy-duty, 15 amp-rated
extension cord if needed.
Failure to use the
recommended extension
cord in good operating
condition, or using a
damaged heater or
extension cord, could make
(Continued) Warning (Continued) it overheat and cause a fire,
property damage, electric
shock, and injury.
.
Do not operate the vehicle
with the heater cord
permanently attached to the
vehicle. Possible heater
cord and thermostat
damage could occur.
.
While in use, do not let the
heater cord touch vehicle
parts or sharp edges. Never
close the hood on the
heater cord.
.
Before starting the vehicle,
unplug the cord, reattach
the cover to the plug, and
securely fasten the cord.
Keep the cord away from
any moving parts.
4. Before starting the engine, be
sure to unplug and store the
cord as it was before to keep it

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
340 Driving and Operating go to a weigh station and weigh the
vehicle. Your dealer can also help
with this.
The total vehicle reserve capacity
for the vehicle is in the lower right
corner of the Certification/Tire label
as shown previously.
See your dealer for additional
advice and information about using
a snow plow on the vehicle. Also,
see Vehicle Load Limits 0 248 .
Emergency Roof Lamp
Provisions Vehicles with the RPO VYU snow
plow prep package also have an
emergency roof lamp provision
package, RPO TRW. Wiring for the
emergency roof lamp is provided
above the overhead console. See
Auxiliary Roof-Mounted Lamp 0 182
for switch location. Pickup Conversion to
Chassis Cab We are aware that some vehicle
owners might consider having the
pickup box removed and a
commercial or recreational body
installed. Owners should be aware
that, as manufactured, there are
differences between a chassis cab
and a pickup with the box removed
which could affect vehicle safety.
The components necessary to adapt
a pickup to permit its safe use with
a specialized body should be
installed by the body builder.