engine GMC SIERRA 2018 Service Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
222 Infotainment System
Software in the Product for the
purpose intended by the
Manufacturer. If permitted by the
Manufacturer, or by applicable law,
you may make one backup copy of
the Software as part of the Product
software. QSSC and its licensors
reserve all license+C31 rights not
expressly granted herein, and retain
all right, title and interest in and to
all copies of the Software, including
all intellectual property rights
therein. Unless required by
applicable law you may not
reproduce, distribute or transfer,
or de-compile, disassemble or
otherwise attempt to unbundle,
reverse engineer, modify or create
derivative works of, the Software.
You agree: (1) not to remove, cover
or alter any proprietary notices,
labels or marks in or on the
Software, and to ensure that all
copies bear any notice contained on
the original; and (2) not to export the
Product or the Software in
contravention of applicable export
control laws.EXCEPT TO THE EXTENT
OTHERWISE REQUIRED BY
APPLICABLE LAW, QSSC AND ITS
LICENSORS PROVIDE THE
SOFTWARE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND,
EITHER EXPRESS OR IMPLIED
INCLUDING, WITHOUT
LIMITATION, ANY WARRANTIES
OR CONDITIONS OF TITLE,
NON-INFRINGEMENT,
MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE.
ANY WARRANTIES OR OTHER
PROVISIONS OFFERED BY THE
MANUFACTURER OR ITS
DISTRIBUTOR(S) THAT DIFFER
FROM THIS LICENSE ARE
OFFERED BY THE
MANUFACTURER OR ITS
DISTRIBUTOR(S) ALONE AND
NOT BY QSSC, ITS AFFILIATES
OR THEIR LICENSORS. YOU
ASSUME ANY RISKS
ASSOCIATED WITH YOUR USE
OF THE SOFTWARE UNDER THIS
LICENSE.EXCEPT TO THE EXTENT
OTHERWISE REQUIRED BY
APPLICABLE LAW (SUCH AS IN
THE CASE OF DELIBERATE OR
GROSSLY NEGLIGENT ACTS), IN
NO EVENT SHALL QSSC, ITS
AFFILIATES OR THEIR
LICENSORS BE LIABLE TO YOU
UNDER ANY LEGAL THEORY,
WHETHER IN TORT (INCLUDING
NEGLIGENCE), CONTRACT OR
OTHERWISE, FOR DAMAGES,
INCLUDING ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL,
OR CONSEQUENTIAL DAMAGES
OF ANY CHARACTER ARISING AS
A RESULT OF THIS LICENSE OR
OUT OF THE USE OR INABILITY
TO USE THE PRODUCT
(INCLUDING BUT NOT LIMITED
TO DAMAGES FOR LOSS OF
GOODWILL, WORK STOPPAGE,
PRODUCT FAILURE OR
MALFUNCTION, OR ANY AND ALL
OTHER COMMERCIAL DAMAGES
OR LOSSES), EVEN IF QSSC, ITS
AFFILIATES OR THEIR
LICENSORS HAVE BEEN
ADVISED OF THE POSSIBILITY
OF SUCH DAMAGES.

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 LoadingInformation . . . . . . . . . . . . . . . . . . 253
Starting and Operating
New Vehicle Break-In . . . . . . . . . 255
Adjustable Throttle and BrakePedal . . . . . . . . . . . . . . . . . . . . . . . 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 BrakeSystem (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 FuelRequirements . . . . . . . . . . . . . . . 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 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
238 Driving and Operating
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.
Caution
If the steering wheel is turned
until it reaches the end of its
travel, and is held in that position
for more than 15 seconds,
damage may occur to the power
steering system and there may be
loss of power steering assist.
Curve Tips
.Take curves at a reasonable
speed.
. Reduce speed before entering a
curve.
. Maintain a reasonable steady
speed through the curve.
. Wait until the vehicle is out of
the curve before accelerating
gently into the straightaway.
Steering in Emergencies
.There are some situations when
steering around a problem may
be more effective than braking.
. Holding both sides of the
steering wheel allows you to turn
180 degrees without removing
a hand.
. Antilock Brake System (ABS)
allows steering while braking.
Off-Road Recovery
The vehicle's right wheels can drop
off the edge of a road onto the
shoulder while driving. Follow
these tips:
1. Ease off the accelerator and then, if there is nothing in the
way, steer the vehicle so that it
straddles the edge of the
pavement.
2. Turn the steering wheel about one-eighth of a turn, until the
right front tire contacts the
pavement edge.
3. Turn the steering wheel to go straight down the roadway.
Loss of Control
Skidding
There are three types of skids that
correspond to the vehicle's three
control systems:
.Braking Skid —wheels are not
rolling.
. Steering or Cornering Skid —
too much speed or steering in a
curve causes tires to slip and
lose cornering force.

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.
Caution
Operating 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 andTires 0389.
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 0264.
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
Driving and Operating 241
Warning (Continued)
cause a rollover. You could be
injured or killed. Do not drive on
steep hills.
Before driving on a hill, assess the
steepness, traction, and
obstructions. If the terrain ahead
cannot be seen, get out of the
vehicle and walk the hill before
driving further.
When driving on hills:
. Use a low gear and keep a firm
grip on the steering wheel.
. Maintain a slow speed.
. When possible, drive straight up
or down the hill.
. Slow down when approaching
the top of the hill.
. Use headlamps even during the
day to make the vehicle more
visible.
{Warning
Driving to the top of a hill at high
speed can cause an accident.
There could be a drop-off,
embankment, cliff, or even
another vehicle. You could be
seriously injured or killed. As you
near the top of a hill, slow down
and stay alert.
. Never go downhill forward or
backward with either the
transmission or transfer case in
N (Neutral). The brakes could
overheat and you could lose
control.
{Warning
If the vehicle has the two-speed
automatic or electronic transfer
case, shifting the transfer case to
N (Neutral) can cause your
vehicle to roll even if the
transmission is in P (Park). This is
(Continued)
Warning (Continued)
because the N (Neutral) position
on the transfer case overrides the
transmission. You or someone
else could be injured. If leaving
the vehicle, set the parking brake
and shift the transmission to
P (Park). Shift the transfer case to
any position but N (Neutral).
. When driving down a hill, keep
the vehicle headed straight
down. Use a low gear because
the engine will work with the
brakes to slow the vehicle and
help keep the vehicle under
control.
{Warning
Heavy braking when going down
a hill can cause your brakes to
overheat and fade. This could
cause loss of control and you or
others could be injured or killed.
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
242 Driving and Operating
Warning (Continued)
Apply the brakes lightly when
descending a hill and use a low
gear to keep vehicle speed under
control.
If the vehicle stalls on a hill: 1. Apply the brakes to stop the vehicle, and then apply the
parking brake.
2. Shift into P (Park) and then restart the engine.
.If driving uphill when the
vehicle stalls, shift to
R (Reverse), release the
parking brake, and back
straight down.
. Never try to turn the vehicle
around. If the hill is steep
enough to stall the vehicle,
it is steep enough to cause
it to roll over.
. If you cannot make it up the
hill, back straight down
the hill. .
Never back down a hill in
N (Neutral) using only the
brake. The vehicle can roll
backward quickly and you
could lose control.
. If driving downhill when the
vehicle stalls, shift to a
lower gear, release the
parking brake, and drive
straight down the hill.
3. If the vehicle cannot be restarted after stalling, set the
parking brake, shift into
P (Park), and turn the
vehicle off.
3.1. Leave the vehicle and seek help.
3.2. Stay clear of the path the vehicle would take if it
rolled downhill.
. Avoid turns that take the vehicle
across the incline of the hill.
A hill that can be driven straight
up or down might be too steep to
drive across. Driving across an
incline puts more weight on the downhill wheels, which could
cause a downhill slide or a
rollover.
. Surface conditions can be a
problem. Loose gravel, muddy
spots, or even wet grass can
cause the tires to slip sideways,
downhill. If the vehicle slips
sideways, it can hit something
that will trip it —a rock, a rut,
etc. —and roll over.
. Hidden obstacles can make the
steepness of the incline more
severe. If a rock is driven across
with the uphill wheels, or if the
downhill wheels drop into a rut
or depression, the vehicle can tilt
even more.
. If an incline must be driven
across, and the vehicle starts to
slide, turn downhill. This should
help straighten out the vehicle
and prevent the side slipping.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 243
{Warning
Getting out of the vehicle on the
downhill side when stopped
across an incline is dangerous.
If the vehicle rolls over, you could
be crushed or killed. Always get
out on the uphill side of the
vehicle and stay well clear of the
rollover path.
Driving in Mud, Sand, Snow,
or Ice
Use a low gear when driving in mud
—the deeper the mud, the lower
the gear. Keep the vehicle moving
to avoid getting stuck.
Traction changes when driving on
sand. On loose sand, such as on
beaches or sand dunes, the tires
tend to sink into the sand. This
affects steering, accelerating, and
braking. Drive at a reduced speed
and avoid sharp turns or abrupt
maneuvers. Traction is reduced on hard packed
snow and ice and it is easy to lose
control. Reduce vehicle speed when
driving on hard packed snow
and ice.
{Warning
Driving on frozen lakes, ponds,
or rivers can be dangerous. Ice
conditions vary greatly and the
vehicle could fall through the ice;
you and your passengers could
drown. Drive your vehicle on safe
surfaces only.
Driving in Water
{Warning
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream
and you and your passengers
could drown. If it is only shallow
water, it can still wash away the
ground from under your tires.
(Continued)
Warning (Continued)
Traction could be lost, and the
vehicle could roll over. Do not
drive through rushing water.
Caution
Do not drive through standing
water if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe. Deep water can damage the
axle and other vehicle parts.
If the standing water is not too deep,
drive through it slowly. At faster
speeds, water can get into the
engine and cause it to stall. Stalling
can occur if the exhaust pipe is
under water. Do not turn off the
ignition when driving through water.
If the exhaust pipe is under water,
the engine will not start. When going
through water, the brakes get wet
and it may take longer to stop. See
“Driving on Wet Roads” later in this
section.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 245
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips include:
.Keep the vehicle serviced and in
good shape.
. Check all fluid levels and brakes,
tires, cooling system, and
transmission.
. Shift to a lower gear when going
down steep or long hills.
{Warning
Using the brakes to slow the
vehicle on a long downhill slope
can cause brake overheating, can
reduce brake performance, and
could result in a loss of braking.
Shift the transmission to a lower
gear to let the engine assist the
brakes on a steep downhill slope.
{Warning
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. This can cause
overheating of the brakes and
loss of steering assist. Always
have the engine running and the
vehicle in gear.
. Drive at speeds that keep the
vehicle in its own lane. Do not
swing wide or cross the
center line.
. Be alert on top of hills;
something could be in your lane
(e.g., stalled car, accident).
. Pay attention to special road
signs (e.g., falling rocks area,
winding roads, long grades,
passing or no-passing zones)
and take appropriate action.
Winter Driving
Driving on Snow or Ice
Snow or ice between the tires and
the road creates less traction or
grip, so drive carefully. Wet ice can
occur at about 0 °C (32 °F) when
freezing rain begins to fall. Avoid
driving on wet ice or in freezing rain
until roads can be treated.
For Slippery Road Driving:
.Accelerate gently. Accelerating
too quickly causes the wheels to
spin and makes the surface
under the tires slick.
. Turn on Traction Control. See
Traction Control/Electronic
Stability Control 0282.
. The Antilock Brake System
(ABS) improves vehicle stability
during hard stops, but the
brakes should be applied sooner
than when on dry pavement.
See Antilock Brake System
(ABS) 0280.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
246 Driving and Operating
.Allow greater following distance
and watch for slippery spots. Icy
patches can occur on otherwise
clear roads in shaded areas.
The surface of a curve or an
overpass can remain icy when
the surrounding roads are clear.
Avoid sudden steering
maneuvers and braking while
on ice.
. Turn off cruise control.
Blizzard Conditions
Stop the vehicle in a safe place and
signal for help. Stay with the vehicle
unless there is help nearby.
If possible, use Roadside
Assistance. See Roadside
Assistance Program 0469. To get
help and keep everyone in the
vehicle safe:
. Turn on the hazard warning
flashers.
. Tie a red cloth to an outside
mirror.
{Warning
Snow can trap engine exhaust
under the vehicle. This may
cause exhaust gases to get
inside. Engine exhaust contains
carbon monoxide (CO), which
cannot be seen or smelled. It can
cause unconsciousness and even
death.
If the vehicle is stuck in snow:
. Clear snow from the base of
the vehicle, especially any
blocking the exhaust pipe.
. Open a window about 5 cm
(2 in) on the vehicle side
that is away from the wind,
to bring in fresh air.
. Fully open the air outlets on
or under the instrument
panel.
. Adjust the climate control
system to circulate the air
inside the vehicle and set
(Continued)
Warning (Continued)
the fan speed to the highest
setting. See“Climate
Control Systems.”
For more information about CO,
see Engine Exhaust 0264.
To save fuel, run the engine for
short periods to warm the vehicle
and then shut the engine off and
partially close the window. Moving
about to keep warm also helps.
If it takes time for help to arrive,
when running the engine, push the
accelerator pedal slightly so the
engine runs faster than the idle
speed. This keeps the battery
charged to restart the vehicle and to
signal for help with the headlamps.
Do this as little as possible, to
save fuel.