
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
440 Vehicle Care Steering, Suspension, and
Chassis Components Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear at
least once a year.
Inspect power steering for proper
attachment, connections, binding,
leaks, cracks, chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
1500 Series vehicles, at least every
other oil change lubricate the outer
tie rod ends.
2500/3500 Series vehicles, at least
every other engine oil change
lubricate the upper and lower
control arm ball joints. Control arm
ball joints on 1500 series vehicles
are maintenance-free.
2500/3500 Series vehicles equipped
with steering linkage, at least every
other engine oil change lubricate the
tie rod ball joints, idler arm pivot
shaft bearings, idler arm socket, and
pitman arm socket. CautionLubrication of applicable steering/
suspension points should not be
done unless the temperature is
− 12 °C (10 °F) or higher,
or damage could result.
For an eAssist vehicle, see the
Silverado/Sierra eAssist
supplement.
Body Component Lubrication Lubricate all key lock cylinders,
hood hinges, liftgate hinges, and the
steel fuel door hinge unless the
components are plastic. Applying
silicone grease on weatherstrips
with a clean cloth will make them
last longer, seal better, and not stick
or squeak.
Underbody Maintenance
At least twice a year, spring and fall,
use plain water to flush any
corrosive materials from the
underbody. Take care to thoroughly
clean any areas where mud and other debris can collect. If equipped
with power assist steps, extend
them and then use a high pressure
wash to clean all joints and gaps.
Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water
can overcome the seals and
contaminate the fluid. Contaminated
fluid will decrease the life of the
transfer case and/or axles and
should be replaced.
Sheet Metal Damage If the vehicle is damaged and
requires sheet metal repair or
replacement, make sure the body
repair shop applies anti-corrosion
material to parts repaired or
replaced to restore corrosion
protection.
Original manufacturer replacement
parts will provide the corrosion
protection while maintaining the
vehicle warranty.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 441Finish Damage Quickly repair minor chips and
scratches with touch-up materials
available from your dealer to avoid
corrosion. Larger areas of finish
damage can be corrected in your
dealer's body and paint shop.
Chemical Paint Spotting Airborne pollutants can fall upon
and attack painted vehicle surfaces
causing blotchy, ring-shaped
discolorations, and small, irregular
dark spots etched into the paint
surface. Refer to “ Finish Care ”
previously in this section.
Interior Care To prevent dirt particle abrasions,
regularly clean the vehicle's interior.
Immediately remove any soils.
Newspapers or dark garments can
transfer color to the vehicle ’ s
interior.
Use a soft bristle brush to remove
dust from knobs and crevices on the
instrument cluster. Using a mild
soap solution, immediately remove hand lotions, sunscreen, and insect
repellent from all interior surfaces or
permanent damage may result.
Use cleaners specifically designed
for the surfaces being cleaned to
prevent permanent damage. Apply
cleaners directly to the cleaning
cloth. Do not spray cleaners on any
switches or controls. Remove
cleaners quickly.
Before using cleaners, read and
follow all safety instructions on the
label. While cleaning the interior,
open the doors and windows to get
proper ventilation.
To prevent damage, do not clean
the interior using the following
cleaners or techniques:
.
Never use a razor or any other
sharp object to remove soil from
any interior surface.
.
Never use a brush with stiff
bristles.
.
Never rub any surface
aggressively or with too much
pressure. .
Do not use laundry detergents or
dishwashing soaps with
degreasers. For liquid cleaners,
use approximately 20 drops per
3.8 L (1 gal) of water.
A concentrated soap solution will
create streaks and attract dirt.
Do not use solutions that contain
strong or caustic soap.
.
Do not heavily saturate the
upholstery when cleaning.
.
Do not use solvents or cleaners
containing solvents.
Interior Glass To clean, use a terry cloth fabric
dampened with water. Wipe droplets
left behind with a clean dry cloth.
If necessary, use a commercial
glass cleaner after cleaning with
plain water.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
448 Service and Maintenance
Maintenance
Schedule Owner Checks and Services At Each Fuel Stop
.
Check the engine oil level. See
Engine Oil 0 350 .
Once a Month
.
Check the tire inflation
pressures. See Tire Pressure
0 397 .
.
Inspect the tires for wear. See
Tire Inspection 0 404 .
.
Check the windshield washer
fluid level. See Washer Fluid
0 366 .
Engine Oil Change When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the
engine oil life system may not
indicate the need for vehicle service
for up to a year. The engine oil and filter must be changed at least once
a year and the oil life system must
be reset. Your trained dealer
technician can perform this work.
If the engine oil life system is reset
accidentally, service the vehicle
within 5 000 km/3,000 mi since the
last service. Reset the oil life
system when the oil is changed.
See Engine Oil Life System 0 353 .
Passenger Compartment Air
Filter The passenger compartment air
filter removes dust, pollen, and
other airborne irritants from outside
air that is pulled into the vehicle.
The filter should be replaced as part
of routine scheduled maintenance.
Inspect the passenger compartment
air filter every 36 000 km/
22,500 miles or two years,
whichever comes first. Replace if
necessary. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, areas with poor air quality,
or areas with high dust levels. Replacement may also be needed if
there is a reduction in air flow,
excessive window fogging, or odors.
Tire Rotation and Required
Services Every 12 000 km/
7,500 mi Rotate the tires, if recommended for
the vehicle, and perform the
following services. See Tire
Rotation 0 405 .
.
Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil 0 350 and Engine Oil Life
System 0 353 .
.
Check engine coolant level. See
Cooling System 0 359 .
.
Check windshield washer fluid
level. See Washer Fluid 0 366 .
.
Visually inspect windshield wiper
blades for wear, cracking,
or contamination. See Exterior
Care 0 435 . Replace worn or
damaged wiper blades. See
Wiper Blade Replacement
0 375 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Service and Maintenance 449.
Check tire inflation pressures.
See Tire Pressure 0 397 .
.
Inspect tire wear. See Tire
Inspection 0 404 .
.
Visually check for fluid leaks.
.
Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter
0 358 .
.
Inspect brake system. See
Exterior Care 0 435 .
.
Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear
at least once a year. See
Exterior Care 0 435 . Lubricate
the suspension and steering
components at least every other
oil change. (If equipped with
grease fittings)
.
Check restraint system
components. See Safety System
Check 0 75 . .
Visually inspect fuel system for
damage or leaks.
.
Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts.
.
Lubricate body components. See
Exterior Care 0 435 .
.
Check starter switch. See Starter
Switch Check 0 374 .
.
Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check
0 374 .
.
Check ignition transmission lock.
See Ignition Transmission Lock
Check 0 374 .
.
Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check
0 375 . .
Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
.
Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. If the hold
open ability is low, service the
gas strut. See Gas Strut(s)
0 376 .
.
Inspect sunroof track and seal,
if equipped. See Sunroof 0 55 .
.
Verify spare tire key lock
operation and lubricate as
needed. See Tire Changing
0 415 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Service and Maintenance 451Footnotes — Maintenance
Schedule Additional Required
Services — Normal
(1) Or every two years, whichever
comes first. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter
replacement may also be needed if
you notice reduced airflow, windows
fogging up, or odors. Your local GM
Service location can help you
determine when it is the right time to
replace your filter. (2) Visually check all fuel and vapor
lines and hoses for proper
attachment, connection, routing, and
condition.
(3) Or every four years, whichever
comes first. If driving in dusty
conditions, inspect the filter at each
oil change or more often as needed.
(4) Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water
can overcome the seals and
contaminate the transfer case fluid.
Contaminated fluid will decrease the
life of the transfer case and/or axles
and should be replaced. (5) Or every five years, whichever
comes first. See Cooling System
0 359 .
(6) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.
(7) Replace brake fluid every five
years. See Brake Fluid 0 368 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Service and Maintenance 453(2) Visually check all fuel and vapor
lines and hoses for proper
attachment, connection, routing, and
condition.
(3) Or every four years, whichever
comes first. If driving in dusty
conditions, inspect the filter at each
oil change or more often as needed.
(4) Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water
can overcome the seals and
contaminate the transfer case fluid.
Contaminated fluid will decrease the
life of the transfer case and/or axles
and should be replaced.
(5) Or every five years, whichever
comes first. See Cooling System
0 359 .
(6) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.
(7) Replace brake fluid every five
years. See Brake Fluid 0 368 .Special Application
Services .
Vehicles with Dual Wheels:
Check dual wheel nut torque at
160, 1 600, and 10 000 km (100,
1,000, and 6,000 mi) of driving.
Repeat this service whenever a
tire/wheel is serviced or
removed.
.
Severe Commercial Use
Vehicles Only: Lubricate chassis
components every oil change.
.
Have underbody flushing service
performed. See “ Underbody
Maintenance ” in Exterior Care
0 435 .Additional
Maintenance and Care Your vehicle is an important
investment and caring for it properly
may help to avoid future costly
repairs. To maintain vehicle
performance, additional
maintenance services may be
required.
It is recommended that your dealer
perform these services — their
trained dealer technicians know
your vehicle best. Your dealer can
also perform a thorough
assessment with a multi-point
inspection to recommend when your
vehicle may need attention.
The following list is intended to
explain the services and conditions
to look for that may indicate
services are required.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
OnStar 483OnStar Advisor. On some vehicles,
Wi-Fi can also be managed from the
Wi-Fi Hotspot menu.
MyGMC Mobile App (If Available)
Download the myGMC mobile app
to compatible Apple and Android
smartphones. GMC users can
access the following services from a
smartphone:
.
Remotely start/stop the vehicle,
if factory-equipped.
.
Lock/unlock doors, if equipped
with automatic locks.
.
Activate the horn and lamps.
.
Check the vehicle ’ s fuel level, oil
life, or tire pressure,
if factory-equipped with the Tire
Pressure Monitor System.
.
Send destinations to the vehicle.
.
Locate the vehicle on a map
(U.S. market only).
.
Turn the vehicle's Wi-Fi hotspot
on/off, manage settings, and
monitor data consumption,
if equipped. .
Locate a dealer and schedule
service.
.
Request roadside assistance.
.
Set a parking reminder with pin
drop, take a photo, make a note,
and set a timer.
.
Connect with GMC on social
media.
For myGMC mobile app information
and compatibility, see
www.my.gmc.com.
An active OnStar service,
compatible device, factory-installed
remote start, and power locks are
required. Data rates apply. See
onstar.com for details and system
limitations.
Remote Services Contact an OnStar Advisor to
unlock the doors or sound the horn
and flash the lamps. OnStar AtYourService OnStar Advisors can provide offers
from restaurants and retailers on
your route, help locate hotels,
or book a room. These services
vary by market.
OnStar Hands-Free Calling Make and receive calls with the
built-in wireless calling service,
which requires available minutes.
Functionality of the Voice Command
button may vary by vehicle and
region. For some vehicles, press
= to open the OnStar app on the
infotainment display, then select
Hands-Free calling. For other
vehicles press
= as follows.
Make a Call
1. Press
= . System responds:
“ OnStar ready. ”
2. Say “ Call. ” System responds:
“ Call. Please say the name or
number to call. ”