GMC SIERRA DENALI 2018 Owners Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
430 Vehicle Care CautionIf the jumper cables are
connected or removed in the
wrong order, electrical shorting
may occur and damage the
vehicle. The repairs would not be
covered by the vehicle warranty.
Always connect and remove the
jumper cables in the correct order,
making sure that the cables do
not touch each other or other
metal.
Jumper Cable Removal
Reverse the sequence exactly when
removing the jumper cables.
After starting the disabled vehicle
and removing the jumper cables,
allow it to idle for several minutes. Towing the Vehicle CautionIncorrectly towing a disabled
vehicle may cause damage. The
damage would not be covered by
the vehicle warranty.
Do not lash or hook to
suspension components. Use the
proper straps around the tires to
secure the vehicle.
Use only a flatbed tow truck for
towing a disabled vehicle. Never
use a sling type lift or damage will
occur. Use ramps to help reduce
approach angles if necessary.
A towed vehicle should have its
drive wheels off the ground.
Consult a professional towing
service if the disabled vehicle must
be towed. Front Attachment Points
The vehicle is equipped with
specific attachment points to be
used to pull the vehicle onto a
flatbed car carrier from a flat road
surface. Do not use these
attachment points to pull the vehicle
from snow, mud or sand.
Recreational Vehicle
Towing Recreational vehicle towing means
towing the vehicle behind another
vehicle, such as a motor home. The
two most common types of

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 431recreational vehicle towing are
dinghy and dolly towing. Dinghy
towing is towing the vehicle with all
four wheels on the ground. Dolly
towing is towing the vehicle with two
wheels on the ground and two
wheels on a dolly.
Follow the tow vehicle
manufacturer ’ s instructions. See
your dealer or trailering professional
for additional advice and equipment
recommendations.
CautionUse of a shield mounted in front
of the vehicle grille could restrict
airflow and cause damage to the
transmission. The repairs would
not be covered by the vehicle
warranty. If using a shield, only
use one that attaches to the
towing vehicle. Dinghy Towing Two-Wheel-Drive Vehicles
CautionIf the two-wheel-drive vehicle is
towed with all four wheels on the
ground, the drivetrain
components could be damaged.
The repairs would not be covered
by the vehicle warranty.
Two-wheel-drive vehicles should not
be towed with all four wheels on the
ground. Four-Wheel-Drive Vehicles
Only dinghy tow four-wheel-drive
vehicles with a two-speed transfer
case that have an N (Neutral) and a
Four-Wheel Drive Low (4 (
n ) setting.
{ Warning
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or others could
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
432 Vehicle Care Warning (Continued)be injured. Set the parking brake
before shifting the transfer case
to N (Neutral).
To dinghy tow:
1. Position the vehicle being
towed behind the tow vehicle,
facing forward and on a level
surface.
2. Securely attach the vehicle
being towed to the tow vehicle.
3. Apply the parking brake and
start the engine.
4. Shift the transfer case to
N (Neutral). See “ Shifting into
N (Neutral) ” under Four-Wheel
Drive 0 272 . Check that the
vehicle is in N (Neutral) by
shifting the transmission to
R (Reverse) and then to D
(Drive). There should be no
movement of the vehicle while
shifting.
5. Turn the engine off. CautionFailure to disconnect the negative
battery cable or to have it contact
the terminals can cause damage
to the vehicle.
6. Disconnect the negative
battery cable at the battery and
secure the nut and bolt. Cover
the negative battery post with a
non-conductive material to
prevent any contact with the
negative battery terminal.
7. Shift the transmission to
P (Park).
Caution
If the steering column is locked,
vehicle damage may occur.
8. Move the steering wheel to
make sure the steering column
is unlocked. 9. With a foot on the brake pedal,
release the parking brake.
Keep the ignition key in the
towed vehicle in ACC/
ACCESSORY to prevent the
steering column from locking.
Disconnecting the Towed Vehicle
Before disconnecting the towed
vehicle:
1. Park on a level surface.
2. Set the parking brake, then
shift the transmission to
P (Park), and turn the ignition
key off.
3. Connect the battery.
4. Apply the brake pedal.
5. Turn the ignition on with the
engine off. Shift the transfer
case out of N (Neutral) to
Two-Wheel Drive High. See
“ Shifting out of N (Neutral) ”
under Four-Wheel Drive 0 272 .
See your dealer if the transfer
case cannot be shifted out of
N (Neutral).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 4336. Check that the vehicle is in
Two-Wheel Drive High by
shifting the transmission to
R (Reverse) and then to D
(Drive). There should be
movement of the vehicle while
shifting.
7. Shift the transmission to
P (Park) and turn off the
ignition.
8. Disconnect the vehicle from the
tow vehicle.
9. Release the parking brake.
10. Reset any lost presets.
The outside temperature
display will default to 0 °C
(32 °F) but will reset with
normal usage. Dolly Towing Front Towing (Front Wheels Off
the Ground) – Two-Wheel-Drive
Vehicles
Caution
If a two-wheel-drive vehicle is
towed with the rear wheels on the
ground, the transmission could be
damaged. The repairs would not
be covered by the vehicle
warranty. Never tow the vehicle
with the rear wheels on the
ground. Two-wheel-drive vehicles should not
be towed with the rear wheels on
the ground. Two-wheel-drive
transmissions have no provisions
for internal lubrication while being
towed.
To dolly tow a two-wheel-drive
vehicle, the vehicle must be towed
with the rear wheels on the dolly.
See “ Rear Towing (Rear Wheels Off
the Ground) ” later in this section.
Front Towing (Front Wheels Off
the Ground) – Four-Wheel-Drive
Vehicles

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
434 Vehicle Care To dolly tow a four-wheel-drive
vehicle from the front:
1. Attach the dolly to the tow
vehicle following the dolly
manufacturer's instructions.
2. Drive the front wheels onto the
dolly.
3. Shift the transmission to
P (Park).
4. Set the parking brake.
{ WarningShifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or others could
be injured. Set the parking brake
before shifting the transfer case
to N (Neutral). 5. Use a clamping device
designed for towing to ensure
that the front wheels are locked
into the straight position.
6. Secure the vehicle to the dolly
following the manufacturer's
instructions.
7. Shift the transfer case to
N (Neutral). See “ Shifting into
N (Neutral) ” under Four-Wheel
Drive 0 272 for the proper
procedure.
8. Release the parking brake only
after the vehicle being towed is
firmly attached to the tow
vehicle.
9. Turn the ignition off. Rear Towing (Rear Wheels Off
the Ground) Two-Wheel-Drive Vehicles
To dolly tow a two-wheel-drive
vehicle from the rear:
1. Drive the rear wheels onto the
dolly.
2. Set the parking brake. See
Parking Brake 0 281 .
3. Put the transmission in
P (Park).
4. Secure the vehicle to the dolly
following the manufacturer's
instructions.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 4355. Use a clamping device
designed for towing to ensure
that the front wheels are locked
into the straight position.
6. Turn the ignition off.
Four-Wheel-Drive Vehicles
{ WarningShifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or others could
be injured. Set the parking brake
before shifting the transfer case
to N (Neutral). To dolly tow a four-wheel-drive
vehicle from the rear:
1. Drive the rear wheels onto the
dolly.
2. Set the parking brake. See
Parking Brake 0 281 .
3. Put the transmission in
P (Park).
4. Secure the vehicle to the dolly
following the manufacturer's
instructions.
5. Use a clamping device
designed for towing to ensure
that the front wheels are locked
into the straight position.
6. Shift the transfer case to
N (Neutral). See “ Shifting into
N (Neutral) ” under Four-Wheel
Drive 0 272 for the proper
procedure.
7. Turn the ignition off. Appearance Care Exterior Care Locks Locks are lubricated at the factory.
Use a de-icing agent only when
absolutely necessary, and have the
locks greased after using. See
Recommended Fluids and
Lubricants 0 456 .
Washing the Vehicle To preserve the vehicle's finish,
wash it often and out of direct
sunlight.
{ Warning
Do not power wash any part of
the vehicle ’ s interior, including the
vinyl floor covering. This could
damage safety and other systems
in the vehicle, which would not be
covered by the vehicle warranty.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
436 Vehicle Care CautionDo not use petroleum-based,
acidic, or abrasive cleaning
agents as they can damage the
vehicle's paint, metal, or plastic
parts. If damage occurs, it would
not be covered by the vehicle
warranty. Approved cleaning
products can be obtained from
your dealer. Follow all
manufacturer directions regarding
correct product usage, necessary
safety precautions, and
appropriate disposal of any
vehicle care product.
Caution
Avoid using high-pressure
washes closer than 30 cm (12 in)
to the surface of the vehicle. Use
of power washers exceeding
8,274 kPa (1,200 psi) can result
in damage or removal of paint
and decals. CautionDo not power wash any
component under the hood that
has this
e symbol.
This could cause damage that
would not be covered by the
vehicle warranty.
If using an automatic car wash,
follow with the car wash
instructions. The windshield wiper
and rear window wiper, if equipped,
must be turned off. Remove any
accessories that may be damaged
or interfere with the car wash
equipment.
See Power Assist Steps 0 43 for
cleaning information.
Rinse the vehicle well, before
washing and after, to remove all
cleaning agents completely. If they
are allowed to dry on the surface,
they could stain. Dry the finish with a soft, clean
chamois or an all-cotton towel to
avoid surface scratches and water
spotting.
Finish Care Application of aftermarket clearcoat
sealant/wax materials is not
recommended. If painted surfaces
are damaged, see your dealer to
have the damage assessed and
repaired. Foreign materials such as
calcium chloride and other salts, ice
melting agents, road oil and tar, tree
sap, bird droppings, chemicals from
industrial chimneys, etc., can
damage the vehicle's finish if they
remain on painted surfaces. Wash
the vehicle as soon as possible.
If necessary, use non-abrasive
cleaners that are marked safe for
painted surfaces to remove foreign
matter.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 437Occasional hand waxing or mild
polishing should be done to remove
residue from the paint finish. See
your dealer for approved cleaning
products.
Do not apply waxes or polishes to
uncoated plastic, vinyl, rubber,
decals, simulated wood, or flat paint
as damage can occur.
CautionMachine compounding or
aggressive polishing on a
basecoat/clearcoat paint finish
may damage it. Use only
non-abrasive waxes and polishes
that are made for a basecoat/
clearcoat paint finish on the
vehicle.
To keep the paint finish looking new,
keep the vehicle garaged or
covered whenever possible. Protecting Exterior Bright Metal
Moldings
CautionFailure to clean and protect the
bright metal moldings can result
in a hazy white finish or pitting.
This damage would not be
covered by the vehicle warranty.
The bright metal moldings on the
vehicle are aluminum, chrome or
stainless steel. To prevent damage
always follow these cleaning
instructions:
.
Be sure the molding is cool to
the touch before applying any
cleaning solution.
.
Use only approved cleaning
solutions for aluminum, chrome
or stainless steel. Some
cleaners are highly acidic or
contain alkaline substances and
can damage the moldings. .
Always dilute a concentrated
cleaner according to the
manufacturer ’ s instructions.
.
Do not use cleaners that are not
intended for automotive use.
.
Use a nonabrasive wax on the
vehicle after washing to protect
and extend the molding finish.
Spray-In Bedliner Care
A spray-in bedliner is a permanent
coating that bonds to the truck bed
and cannot be removed. Promptly
rinse the bedliner surface following
a chemical spill to avoid permanent
damage.
Spray-in bedliners can fade from
oxidation, road dirt, heavy-duty
hauling, and hard water stains.
Clean it periodically by washing off
the loose dirt and using a mild
detergent. To restore the original
appearance, apply the bedliner
conditioner available through your
dealer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
438 Vehicle Care CautionUsing silicone-based products
may damage the bedliner, reduce
the slip-resistant texture, and
attract dirt.
Cleaning Exterior Lamps/
Lenses, Emblems, Decals and
Stripes Use only lukewarm or cold water, a
soft cloth, and a car washing soap
to clean exterior lamps, lenses,
emblems, decals and stripes. Follow
instructions under "Washing the
Vehicle" previously in this section.
Lamp covers are made of plastic,
and some have a UV protective
coating. Do not clean or wipe them
while they are dry.
Do not use any of the following on
lamp covers:
.
Abrasive or caustic agents. .
Washer fluids and other cleaning
agents in higher concentrations
than suggested by the
manufacturer.
.
Solvents, alcohols, fuels,
or other harsh cleaners.
.
Ice scrapers or other hard items.
.
Aftermarket appearance caps or
covers while the lamps are
illuminated, due to excessive
heat generated.
CautionFailure to clean lamps properly
can cause damage to the lamp
cover that would not be covered
by the vehicle warranty.
Caution
Using wax on low gloss black
finish stripes can increase the
gloss level and create a
(Continued) Caution (Continued) non-uniform finish. Clean low
gloss stripes with soap and
water only.
Air Intakes Clear debris from the air intakes,
between the hood and windshield,
when washing the vehicle.
Windshield and Wiper Blades Clean the outside of the windshield
with glass cleaner.
Clean rubber blades using a lint-free
cloth or paper towel soaked with
windshield washer fluid or a mild
detergent. Wash the windshield
thoroughly when cleaning the
blades. Bugs, road grime, sap, and
a buildup of vehicle wash/wax
treatments may cause wiper
streaking.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 439Replace the wiper blades if they are
worn or damaged. Damage can be
caused by extreme dusty
conditions, sand, salt, heat, sun,
snow, and ice.
Weatherstrips Apply weatherstrip lubricant on
weatherstrips to make them last
longer, seal better, and not stick or
squeak. Lubricate weatherstrips
once a year. Hot, dry climates may
require more frequent application.
Black marks from rubber material on
painted surfaces can be removed by
rubbing with a clean cloth. See
Recommended Fluids and
Lubricants 0 456 .
Tires Use a stiff brush with tire cleaner to
clean the tires.
Caution
Using petroleum-based tire
dressing products on the vehicle
may damage the paint finish and/
(Continued) Caution (Continued) or tires. When applying a tire
dressing, always wipe off any
overspray from all painted
surfaces on the vehicle.
Wheels and Trim — Aluminum
or Chrome Use a soft, clean cloth with mild
soap and water to clean the wheels.
After rinsing thoroughly with clean
water, dry with a soft, clean towel.
A wax may then be applied.
Caution
Chrome wheels and other chrome
trim may be damaged if the
vehicle is not washed after driving
on roads that have been sprayed
with magnesium, calcium,
or sodium chloride. These
chlorides are used on roads for
conditions such as ice and dust.
Always wash the chrome with
soap and water after exposure. CautionTo avoid surface damage, do not
use strong soaps, chemicals,
abrasive polishes, cleaners,
brushes, or cleaners that contain
acid on aluminum or
chrome-plated wheels. Use only
approved cleaners. Also, never
drive a vehicle with aluminum or
chrome-plated wheels through an
automatic car wash that uses
silicone carbide tire cleaning
brushes. Damage could occur
and the repairs would not be
covered by the vehicle warranty.
Brake System Visually inspect brake lines and
hoses for proper hook-up, binding,
leaks, cracks, chafing, etc. Inspect
disc brake pads for wear and rotors
for surface condition. Inspect drum
brake linings/shoes for wear or
cracks. Inspect all other brake parts.