2018 GMC SIERRA DENALI tow

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Climate Controls 229The recirculation light will not come
on when automatically controlled.
Press
@ to manually select
recirculation; press it again to select
outside air.
Do not cover the solar sensor on the
top of the instrument panel near the
windshield. This sensor regulates
air temperature based on sun load.
See “ Sensors ” later in this section.
Manual Operation
O : Press to turn the climate control
system on or off. Outside air still
enters the vehicle, and is directed to
the floor. This direction can be
changed by pressing the air
delivery mode.
9 : Turn clockwise or
counterclockwise to increase or
decrease the fan speed. Press the
knob to turn the fan off.
Press AUTO to return to automatic
operation. Driver and Passenger
Temperature Control : The
temperature can be adjusted
separately for the driver and
passenger.
Turn the knob clockwise or
counterclockwise to increase or
decrease the driver or passenger
temperature setting.
SYNC : Press to link the passenger
temperature setting to the driver
setting. The SYNC indicator light will
turn on. When the passenger setting
is adjusted, the SYNC indicator light
is off.
The driver side or passenger side
temperature display shows the
temperature setting increasing or
decreasing.
Air Delivery Mode Control :
Press
Y ,
\ ,
[ , or
- to change
the direction of the airflow. An
indicator light comes on in the
selected mode button. Changing the mode cancels the
automatic operation and the system
goes into manual mode. Press
AUTO to return to automatic
operation.
Y : Air is directed to the instrument
panel outlets.
\ : Air is divided between the
instrument panel and floor outlets.
Some air is directed toward the
windshield and side window outlets.
[ : Air is directed to the floor
outlets, with some to the windshield,
side window outlets, and second
row floor outlets.
- : This mode clears the windows
of fog or moisture. Air is directed to
the windshield, floor outlets, and
side window vents. The system
automatically forces outside air into
the vehicle and the air conditioning
compressor will run, unless the
outside temperature is close to
freezing.
0 : Press to clear the windshield
of fog or frost more quickly. Air is
directed to the windshield and the
side window vents. The air

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
234 Driving and Operating
Driving and
Operating Driving Information Distracted Driving . . . . . . . . . . . . 235
Defensive Driving . . . . . . . . . . . . . 236
Drunk Driving . . . . . . . . . . . . . . . . . 236
Control of a Vehicle . . . . . . . . . . . 236
Braking . . . . . . . . . . . . . . . . . . . . . . . 236
Steering . . . . . . . . . . . . . . . . . . . . . . 237
Off-Road Recovery . . . . . . . . . . . 238
Loss of Control . . . . . . . . . . . . . . . 238
Off-Road Driving . . . . . . . . . . . . . 239
Driving on Wet Roads . . . . . . . . 244
Hill and Mountain Roads . . . . . 245
Winter Driving . . . . . . . . . . . . . . . . 245
If the Vehicle Is Stuck . . . . . . . . 247
Vehicle Load Limits . . . . . . . . . . . 248
Truck-Camper Loading
Information . . . . . . . . . . . . . . . . . . 253
Starting and Operating New Vehicle Break-In . . . . . . . . . 255
Adjustable Throttle and Brake
Pedal . . . . . . . . . . . . . . . . . . . . . . . 256
Ignition Positions . . . . . . . . . . . . . 256
Starting the Engine . . . . . . . . . . . 258
Fast Idle System . . . . . . . . . . . . . 259 Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . . 260
Engine Coolant Heater . . . . . . . 260
Shifting Into Park . . . . . . . . . . . . . 262
Shifting out of Park . . . . . . . . . . . 263
Parking over Things
That Burn . . . . . . . . . . . . . . . . . . . 264
Active Fuel Management . . . . . 264
Engine Exhaust Engine Exhaust . . . . . . . . . . . . . . 264
Running the Vehicle While
Parked . . . . . . . . . . . . . . . . . . . . . . 265
Automatic Transmission Automatic Transmission . . . . . . 265
Manual Mode . . . . . . . . . . . . . . . . . 268
Tow/Haul Mode . . . . . . . . . . . . . . . 271
Drive Systems Four-Wheel Drive . . . . . . . . . . . . . 272
Brakes Antilock Brake
System (ABS) . . . . . . . . . . . . . . . 280
Parking Brake . . . . . . . . . . . . . . . . 281
Brake Assist . . . . . . . . . . . . . . . . . . 281
Hill Start Assist (HSA) . . . . . . . . 282
Ride Control Systems
Traction Control/Electronic
Stability Control . . . . . . . . . . . . . 282 Hill Descent Control (HDC) . . . 284
Locking Rear Axle . . . . . . . . . . . . 285
Cruise Control Cruise Control . . . . . . . . . . . . . . . . 285
Driver Assistance Systems Driver Assistance Systems . . . 288
Assistance Systems for
Parking or Backing . . . . . . . . . . 289
Assistance Systems for
Driving . . . . . . . . . . . . . . . . . . . . . . 292
Forward Collision Alert (FCA)
System . . . . . . . . . . . . . . . . . . . . . . 292
Forward Automatic
Braking (FAB) . . . . . . . . . . . . . . . 294
Lane Departure Warning
(LDW) (2500/3500
Series) . . . . . . . . . . . . . . . . . . . . . . 295
Lane Keep Assist (LKA) (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 297
Fuel Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 299
California Fuel
Requirements . . . . . . . . . . . . . . . 300
Fuels in Foreign Countries . . . 300
Fuel Additives . . . . . . . . . . . . . . . . 300
E85 or FlexFuel . . . . . . . . . . . . . . 300
Filling the Tank . . . . . . . . . . . . . . . 301

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 235Filling a Portable Fuel
Container . . . . . . . . . . . . . . . . . . . 303
Trailer Towing General Towing
Information . . . . . . . . . . . . . . . . . . 303
Driving Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . 303
Trailer Towing . . . . . . . . . . . . . . . . 307
Towing Equipment . . . . . . . . . . . . 325
Trailer Sway Control (TSC) . . . 334
Conversions and Add-Ons Add-On Electrical
Equipment . . . . . . . . . . . . . . . . . . 336
Adding a Snow Plow or Similar
Equipment . . . . . . . . . . . . . . . . . . 337
Pickup Conversion to
Chassis Cab . . . . . . . . . . . . . . . . 340 Driving Information Distracted Driving Distraction comes in many forms
and can take your focus from the
task of driving. Exercise good
judgment and do not let other
activities divert your attention away
from the road. Many local
governments have enacted laws
regarding driver distraction. Become
familiar with the local laws in
your area.
To avoid distracted driving, keep
your eyes on the road, keep your
hands on the steering wheel, and
focus your attention on driving.
.
Do not use a phone in
demanding driving situations.
Use a hands-free method to
place or receive necessary
phone calls.
.
Watch the road. Do not read,
take notes, or look up
information on phones or other
electronic devices. .
Designate a front seat
passenger to handle potential
distractions.
.
Become familiar with vehicle
features before driving, such as
programming favorite radio
stations and adjusting climate
control and seat settings.
Program all trip information into
any navigation device prior to
driving.
.
Wait until the vehicle is parked
to retrieve items that have fallen
to the floor.
.
Stop or park the vehicle to tend
to children.
.
Keep pets in an appropriate
carrier or restraint.
.
Avoid stressful conversations
while driving, whether with a
passenger or on a cell phone.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 237If the engine ever stops while the
vehicle is being driven, brake
normally but do not pump the
brakes. Doing so could make the
pedal harder to push down. If the
engine stops, there will be some
power brake assist but it will be
used when the brake is applied.
Once the power assist is used up, it
can take longer to stop and the
brake pedal will be harder to push.
Steering Electric Power Steering (1500
Series) If the vehicle has electric power
steering, it does not have power
steering fluid. Regular maintenance
is not required.
If power steering assist is lost due
to a system malfunction, the vehicle
can be steered, but may require
increased effort. See your dealer if
there is a problem. If the steering wheel is turned until it
reaches the end of its travel, and is
held in that position for an extended
period of time, power steering assist
may be reduced.
If the steering assist is used for an
extended period of time while the
vehicle is not moving, power assist
may be reduced.
Normal use of the power steering
assist should return when the
system cools down.
See your dealer if there is a
problem.
Hydraulic Power Steering
(2500/3500 Series) (2500/3500 Series – All Regular
Cab, Double Cab/Crew Cab
without Digital Steer Assist)
The power steering system may
require maintenance. See Power
Steering Fluid (1500 Series) 0 365
or Power Steering Fluid (2500/3500
Series) 0 365 . If power steering assist is lost
because the engine stops or the
system malfunctions, the vehicle
can be steered but may require
increased effort. See your dealer.
(2500/3500 Series – Double Cab/
Crew Cab with Digital Steer
Assist)
The vehicle has a Digital Steer
Assist power steering system that
varies the amount of effort required
to steer the vehicle. Less steering
effort is required at slower speeds.
At faster speeds, the steering effort
increases. The system helps the
steering wheel return to center at
low speeds. Pressing the Tow/Haul
button adjusts steering effort for
driving conditions described in Tow/
Haul Mode 0 271 .
The power steering system may
require maintenance. See Power
Steering Fluid (1500 Series) 0 365
or Power Steering Fluid (2500/3500
Series) 0 365 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 247
If the Vehicle Is Stuck Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
See “ Rocking the Vehicle to Get It
Out ” later in this section.
The Traction Control System (TCS)
can often help to free a stuck
vehicle. See Traction Control/
Electronic Stability Control 0 282 .
If TCS cannot free the vehicle, see
“ Rocking the Vehicle to Get it Out ”
following.
{ WarningIf the vehicle's tires spin at high
speed, they can explode, and you
or others could be injured. The
vehicle can overheat, causing an
engine compartment fire or other
damage. Spin the wheels as little
as possible and avoid going
above 56 km/h (35 mph).
For information about using tire
chains on the vehicle, see Tire
Chains 0 413 . Rocking the Vehicle to Get
It Out Turn the steering wheel left and
right to clear the area around the
front wheels. For four-wheel-drive
vehicles, shift into Four-Wheel Drive
High. Turn the TCS off. Shift back
and forth between R (Reverse) and
a forward gear, spinning the wheels
as little as possible. To prevent
transmission wear, wait until the
wheels stop spinning before shifting
gears. Slowly spinning the wheels in
the forward and reverse directions
causes a rocking motion that could
free the vehicle. If that does not get
the vehicle out after a few tries, it
might need to be towed out. See
Towing the Vehicle 0 430 . Recovery
hooks can be used, if the vehicle
has them. Recovery Hooks
{ WarningNever pull on recovery hooks
from the side. The hooks could
break and you and others could
be injured. When using recovery
hooks, always pull the vehicle
from the front.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 249The Tire and Loading
Information label also shows the
size of the original equipment
tires (3) and the recommended
cold tire inflation pressures (4).
For more information on tires
and inflation see Tires 0 389
and Tire Pressure 0 397 .
There is also important loading
information on the vehicle
Certification/Tire label. It may
show the Gross Vehicle Weight
Rating (GVWR) and the Gross
Axle Weight Rating (GAWR) for
the front and rear axles. See
“ Certification/Tire Label ” later in
this section. “ Steps for Determining Correct
Load Limit –
1.
Locate the statement "The
combined weight of
occupants and cargo should
never exceed XXX kg or
XXX lbs." on your vehicle ’ s
placard. 2.
Determine the combined
weight of the driver and
passengers that will be
riding in your vehicle. 3.
Subtract the combined
weight of the driver and
passengers from XXX kg or
XXX lbs. 4.
The resulting figure equals
the available amount of
cargo and luggage load
capacity. For example, if the
"XXX" amount equals
1400 lbs. and there will be
five 150 lb passengers in
your vehicle, the amount of
available cargo and luggage
load capacity is 650 lbs.
(1400-750 (5 x 150) =
650 lbs.) 5.
Determine the combined
weight of luggage and cargo
being loaded on the vehicle.
That weight may not safely
exceed the available cargo
and luggage load capacity
calculated in Step 4. 6.
If your vehicle will be towing
a trailer, load from your
trailer will be transferred to
your vehicle. Consult this
manual to determine how
this reduces the available
cargo and luggage load
capacity of your vehicle. ”
See Trailer Towing 0 307 for
important information on towing
a trailer, towing safety rules, and
trailering tips.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
256 Driving and Operating Caution (Continued) premature wear and earlier
replacement. Follow this
breaking-in guideline every
time you get new brake
linings.
.
Do not tow a trailer during
break-in. See Trailer Towing
0 307 for the trailer towing
capabilities of the vehicle
and more information.
Following break-in, engine speed
and load can be gradually
increased.
Adjustable Throttle and
Brake Pedal If equipped, the position of the
throttle and brake pedals can be
changed.
The pedals can only be adjusted
when the vehicle is in P (Park). The switch used to adjust the
pedals is on the center stack, below
the climate controls.
Lift the switch up to move the
pedals closer to your body. Press
the switch down to move the
pedals away.
Before you start driving, fully press
the brake pedal to confirm the
adjustment is right for you.
The vehicle may have a memory
function, which lets pedal settings
be saved and recalled. See Memory
Seats 0 62 . Ignition Positions
Vehicles with Key Access have an
ignition switch with four different
positions.
To shift out of P (Park), the ignition
must be in ON/RUN or ACC/
ACCESSORY and the regular brake
pedal must be applied.
0 (STOPPING THE ENGINE/LOCK/
OFF) : When the vehicle is stopped,
turn the ignition switch to LOCK/
OFF to turn the engine off. Retained
Accessory Power (RAP) will remain
active. See Retained Accessory
Power (RAP) 0 260 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 257This position locks the ignition and
steering wheel. It also locks the
transmission. The key can be
removed in LOCK/OFF.
The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
does not work, then the vehicle
needs service.
Do not turn the engine off when the
vehicle is moving. This may cause a
loss of power assist in the brake
and steering systems and disable
the airbags.
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steady
pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral).
This can be done while the
vehicle is moving. After shifting to N (Neutral), firmly apply the
brakes and steer the vehicle to
a safe location.
3. Come to a complete stop. Shift
to P (Park). Turn the ignition to
LOCK/OFF.
4. Set the parking brake. See
Parking Brake 0 281 .
The shift lever must be in P (Park)
to turn the ignition switch to
LOCK/OFF.
{ WarningTurning 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.
If the vehicle cannot be pulled over,
and must be shut off while driving,
turn the ignition to ACC/
ACCESSORY. CautionUsing a tool to force the key to
turn in the ignition could cause
damage to the switch or break the
key. Use the correct key, make
sure it is all the way in, and turn it
only with your hand. If the key
cannot be turned by hand, see
your dealer.
1 (ACC/ACCESSORY) : This
position lets things like the radio
and the windshield wipers operate
while the engine is off. It also
unlocks the steering wheel. Use this
position if the vehicle must be
pushed or towed.
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.