Maintenance GMC SIERRA 2018 User Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 159
.Unit
Digital Speedometer
The speedometer shows how fast
the vehicle is moving in either
kilometers per hour (km/h) or miles
per hour (mph). The speedometer
cannot be reset. If equipped, press
the reset stem and select to display
speed limit signs.
Trip
Turn the trip odometer reset stem
until TRIP displays. The current
distance traveled, in either
kilometers (km) or miles (mi), since
the last reset for the trip odometer is
shown. The trip odometer can be
reset to zero by pressing and
holding the trip odometer reset stem
while the trip odometer is displayed.
Fuel Range
This display shows the approximate
distance the vehicle can be driven
without refueling. The fuel range
estimate is based on an average of
the vehicle's fuel economy over recent driving history and the
amount of fuel remaining in the fuel
tank. Fuel range cannot be reset.
Average Fuel Economy
The Average Fuel Economy display
shows the approximate average
liters per 100 kilometers (L/100 km)
or miles per gallon (mpg). This
number reflects only the
approximate average fuel economy
that the vehicle has right now, and
will change as driving conditions
change. This number is based on
the number of L/100 km (mpg)
recorded since the last time this
menu item was reset. Reset this
display by pressing the trip
odometer reset stem.
Tire Pressure
Turn the trip odometer reset stem
until a vehicle with the approximate
pressures of all four tires displays.
Tire pressure is displayed in either
kilopascal (kPa) or in pounds per
square inch (psi).
See
Tire Pressure Monitor System
0 399 andTire Pressure Monitor
Operation 0400. Remaining Oil Life
Turn the trip odometer reset stem
until REMAINING OIL LIFE
displays. An estimate of the oil's
remaining useful life is shown.
REMAINING OIL LIFE 99% means
99% of the current oil life remains.
When the remaining oil life is low,
the CHANGE ENGINE OIL SOON
message will appear on the display.
The oil should be changed as soon
as possible. See
Engine Oil0350.
In addition to the engine oil life
system monitoring the oil life,
additional maintenance is
recommended in the Maintenance
Schedule. See Maintenance
Schedule 0448.
The Oil Life display must be reset
after each oil change. It will not
reset itself. Do not reset the Oil Life
display at any time other than when
the oil has just been changed.
It cannot be reset accurately until
the next oil change. To reset the
engine oil life system, see Engine
Oil Life System 0353.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
162 Instruments and Controls
miles per gallon (mpg). This number
reflects only the approximate fuel
economy that the vehicle has right
now and changes frequently as
driving conditions change.
Timer and Fuel Used :This display
can be used as a timer. To start the
timer, press
Vwhile this display is
active. The display will show the
amount of time that has passed
since the timer was last reset. To
stop the timer, press
Vbriefly while
this display is active and the timer is
running.
This also shows the number of
liters (L) or gallons (gal) of fuel used
since the last reset of this
menu item.
Press and hold
Vwhile this display
is active to reset the timer and fuel
used. Each of these items can be
reset individually by pressing
p
while this display is active. Oil Life :
Shows an estimate of the
oil's remaining useful life.
If REMAINING OIL LIFE 99% is
displayed, that means 99% of the
current oil life remains.
When the remaining oil life is low,
the CHANGE ENGINE OIL SOON
message will appear on the display.
The oil should be changed as soon
as possible. See Engine Oil0350.
In addition to the engine oil life
system monitoring the oil life,
additional maintenance is
recommended in the Maintenance
Schedule. See Maintenance
Schedule 0448.
The Oil Life display must be reset
after each oil change. It will not
reset itself. Do not to reset the Oil
Life display at any time other than
when the oil has just been changed.
It cannot be reset accurately until
the next oil change. To reset the
engine oil life system, press and
holdVfor several seconds while
the Oil Life display is active. See
Engine Oil Life System 0353. Tire Pressure :
Shows the
approximate pressures of all four
tires. Tire pressure is displayed in
either kilopascal (kPa) or in pounds
per square inch (psi). If the pressure
is low, the value for that tire is
shown in amber. See Tire Pressure
Monitor System 0399 andTire
Pressure Monitor Operation 0400.
Best Fuel Economy : Displays
average fuel economy, the best fuel
economy over the selected
distance, and a bar graph showing
instantaneous fuel economy.
Press
pto change the selected
distance. Press and hold
Vwhile
this display is active to reset the
best fuel economy and average fuel
economy. This display can also be
reset by selecting reset in the menu.
Top Consumers : Shows a list of
the features that are currently
impacting the fuel economy, in order
from highest to lowest. If a feature is
turned off, it will be removed from
the list.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
224 Climate Controls
Climate Controls
Climate Control Systems
Climate Control Systems (withHeater Only) . . . . . . . . . . . . . . . . 224
Climate Control Systems (with Air Conditioning) . . . . . . . . . . . . 226
Dual Automatic Climate Control System . . . . . . . . . . . . . 228
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . 231
Maintenance
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . 232
Service . . . . . . . . . . . . . . . . . . . . . . . 233
Climate Control Systems
Climate Control Systems (with Heater Only)
With this system, the heating and ventilation can be controlled.
1. Fan Control
2. Air Recirculation
3. Air Delivery Mode Controls
4. Defrost
5. TEMP (Temperature Control) TEMP :
Turn clockwise or
counterclockwise to increase or
decrease the temperature inside the
vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
232 Climate Controls
Maintenance
Passenger Compartment
Air Filter
The filter reduces the 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.
SeeMaintenance Schedule 0448.
To find out what type of filter to use,
see Maintenance Replacement
Parts 0458.
1. Open the lower glove box door
completely.
2. Remove the four screws from around the lower glove box.
The door does not need to be
removed to access the screws.
3. Close the lower glove box doorand pull it from its frame to
remove the entire unit.
4. Release the two tabs holding
the service door. Open the
service door and remove the
old filter.
5. Install the new air filter.
6. Close the service door and secure the tabs.
7. Reverse the steps to reinstall the glove box.
See your dealer if additional
assistance is needed.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 237
If 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) 0365
or Power Steering Fluid (2500/3500
Series) 0365. 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 0271.
The power steering system may
require maintenance. See Power
Steering Fluid (1500 Series) 0365
or Power Steering Fluid (2500/3500
Series) 0365.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 239
.Acceleration Skid —too much
throttle causes the driving
wheels to spin.
Defensive drivers avoid most skids
by taking reasonable care suited to
existing conditions, and by not
overdriving those conditions. But
skids are always possible.
If the vehicle starts to slide, follow
these suggestions:
. Ease your foot off the
accelerator pedal and steer the
way you want the vehicle to go.
The vehicle may straighten out.
Be ready for a second skid if it
occurs.
. Slow down and adjust your
driving according to weather
conditions. Stopping distance
can be longer and vehicle
control can be affected when
traction is reduced by water,
snow, ice, gravel, or other
material on the road. Learn to
recognize warning clues —such
as enough water, ice, or packed snow on the road to make a
mirrored surface
—and slow
down when you have any doubt.
. Try to avoid sudden steering,
acceleration, or braking,
including reducing vehicle speed
by shifting to a lower gear. Any
sudden changes could cause
the tires to slide.
Remember: Antilock brakes help
avoid only the braking skid.
Off-Road Driving
Four-wheel-drive vehicles can be
used for off-road driving. Vehicles
without four-wheel drive and
vehicles not equipped with All
Terrain (AT) or On-Off Road (OOR)
tires must not be driven off-road
except on a level, solid surface. For
contact information about the
original equipment tires, see the
warranty manual.
One of the best ways for successful
off-road driving is to control the
speed.
{Warning
When driving off-road, bouncing
and quick changes in direction
can easily throw you out of
position. This could cause you to
lose control and crash. You and
your passengers should always
wear seat belts.
Before Driving Off-Road
. Have all necessary maintenance
and service work completed.
. Fuel the vehicle, fill fluid levels,
and check inflation pressure in
all tires, including the spare,
if equipped.
. Read all the information about
four-wheel-drive vehicles in this
manual.
. Remove any underbody air
deflector, if equipped. Re-attach
the air deflector after off-road
driving.
. Know the local laws that apply to
off-road driving.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
244 Driving and Operating
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody or
chassis, or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the body structure, driveline,
steering, suspension, wheels, tires,
and exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
More frequent maintenance service
is required. See theMaintenance
Schedule 0448.
Driving on Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep-standing or flowing water.
{Warning
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under the vehicle's
tires so they actually ride on the
water. This can happen if the road is
wet enough and you are going fast
enough. When the vehicle is
hydroplaning, it has little or no
contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.
Allow extra following distance.
. Pass with caution.
. Keep windshield wiping
equipment in good shape.
. Keep the windshield washer fluid
reservoir filled.
. Have good tires with proper
tread depth. See Tires0389.
. Turn off cruise control.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 307
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule0448.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 363.
Trailer Towing
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
Do not tow a trailer during break-in.
See New Vehicle Break-In 0255.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too heavy
or the trailer brakes are
inadequate for the load, the
vehicle may not stop as expected.
The driver and passengers could
be seriously injured. The vehicle
may also be damaged; the
resulting repairs would not be
covered by the vehicle warranty.
Pull a trailer only if all the steps in
this section have been followed.
Ask your dealer for advice and
information about towing a trailer
with the vehicle.
Caution
Pulling a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.
See Vehicle Load Limits 0248 for
more information about the vehicle's
maximum load capacity.
To identify the trailering capacity of
the vehicle, read the information in
“Weight of the Trailer” later in this
section.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
336 Driving and Operating
Warning (Continued)
(20-25 mph) and fully apply
the manual trailer brake
apply lever. Also check that
the trailer brake lamps and
other lamps are functioning
correctly.
. If the trailer brakes are not
operating properly at any
time, or if a DIC message
indicates problems with the
trailer connections or trailer
brakes, carefully pull the
vehicle over to the side of
the road when traffic
conditions allow.
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service
and Emission Inspection/
Maintenance testing. See
Malfunction Indicator Lamp
(Check Engine Light) 0150.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle’s
systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle 090 and Adding Equipment
to the Airbag-Equipped Vehicle
0 90.
For information on wiring auxiliary
switches, see www.gmupfitter.com
or contact your dealer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
344 Vehicle Care
Vehicle Checks
Doing Your Own
Service Work
{Warning
It can be dangerous to work on
your vehicle if you do not have
the proper knowledge, service
manual, tools, or parts. Always
follow owner’s manual procedures
and consult the service manual
for your vehicle before doing any
service work.
If doing some of your own service
work, use the proper service
manual. It tells you much more
about how to service the vehicle
than this manual can. To order the
proper service manual, see Service
Publications Ordering Information
0 474.
This vehicle has an airbag system.
Before attempting to do your own
service work, see Servicing the
Airbag-Equipped Vehicle 090. Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records
0459.
Caution
Even small amounts of
contamination can cause damage
to vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
To open the hood:
1. Pull the handle with this symbol
on it. It is inside the vehicle
under the steering wheel.
2. Go to the front of the vehicle tofind the secondary hood
release. The handle is under
the front edge of the hood near
the center. Push the handle to
the right and at the same time
raise the hood.
Before closing the hood, be sure all
the filler caps are on properly. Then
bring the hood from full open to
within 15 cm (6 in) from the closed
position, pause, and push the front
center of the hood with a swift, firm
motion to fully close the hood.