Page 337 of 544

Black plate (67,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-67
{Warning
The LDW system is an aid to help
the vehicle stay in the driving
lane. It does not steer the vehicle.
The LDW system may not:
.Provide enough time to avoid
a crash.
.Detect lane markings under
bad weather conditions or if
the windshield is dirty.
.Detect lane markings and will
not detect road edges.
.Warn that the vehicle is
crossing a lane marking if the
system does not detect the
lane marking.
If LDW only detects lane
markings on one side of the road,
it will only warn you when
departing the lane on the side
where it has detected a lane
marker. Even with LDW, always
keep your attention on the road (Continued)
Warning (Continued)
and maintain proper vehicle
position within the lane, or vehicle
damage, injury, or death could
occur. Always keep the
windshield clean and do not use
LDW in bad weather conditions.
How the System Works
The LDW camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LDW on and off, press
@on
the center stack. The control
indicator will light when LDW is on.
When the vehicle is started, the
LDW indicator on the instrument
cluster will come on briefly. If LDW is on, the LDW indicator will
appear green if the system detects
a left or right lane marking while the
vehicle is traveling at 56 km/h
(35 mph) or greater. If the vehicle
crosses a detected lane marking
without using the turn signal in the
lane departure direction, this
indicator will change to amber and
flash. In addition, three beeps will
be sounded from the left or right
side, or the Safety Alert Seat will
pulse three times on either the left
or right side of the seat, depending
on the lane departure direction.
When the System Does Not
Seem to Work Properly
If the LDW symbol does not appear
when the system is on and the
vehicle is traveling at least 56 km/h
(35 mph):
.The lane markings on the road
may not be seen.
.The camera sensor may be
blocked by dirt, snow, or ice.
Page 338 of 544

Black plate (68,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-68 Driving and Operating
.The windshield may be
damaged.
.The weather may be limiting
visibility.
This is normal operation; the vehicle
does not need service. Clean the
windshield.
Lane markings may not be detected
on curves, highway exit ramps,
or hills; or due to poor visibility.
If the LDW camera system does not
seem to operate properly, cleaning
the outside of the windshield in front
of the camera sensor may correct
the issue.
{Warning
LDW does not provide a warning
to help avoid a crash, unless it
detects the lane markings. LDW
may not detect the lane markings
if the camera sensor is blocked
by dirt, snow, or ice, or if the
windshield is damaged. It may (Continued)
Warning (Continued)
also not detect a lane on winding
or hilly roads, or in conditions that
can limit visibility such as fog,
rain, or snow, or if the headlamps
or windshield are not cleaned or
in proper condition. Keep the
windshield, headlamps, and
camera sensors clean and in
good repair.
LDW warnings may occur due to tar
marks, shadows, cracks in the road,
or other road imperfections. This is
normal system operation; the
vehicle does not need service.
Fuel
For diesel engine vehicles, see
“Fuel for Diesel Engines” in the
Duramax diesel supplement.
For gasoline engine vehicles, use of
the recommended fuel is an
important part of the proper
maintenance of this vehicle. When
driving in the U.S., to help keep the
engine clean and maintain optimum
vehicle performance, we
recommend using TOP TIER
Detergent Gasolines.
See www.toptiergas.com for a list of
TOP TIER Detergent Gasolines.
Page 339 of 544

Black plate (69,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-69
If the vehicle has a yellow fuel cap,
E85 or FlexFuel can be used in the
vehicle. SeeE85 or FlexFuel on
page 9-70.
For all vehicles except those with
the 6.2L V8 engine, use regular
unleaded gasoline with a posted
octane rating of 87 or higher. If the
octane rating is less than 87, an
audible knocking noise may be
heard. If this occurs, use a gasoline
rated at 87 octane or higher as soon
as possible. If heavy knocking is
heard when using a higher octane
rated gasoline, the engine needs
service. If the vehicle has the 6.2L V8 engine
(VIN Code J), use premium
unleaded gasoline with a posted
octane rating of 91 or higher.
Regular unleaded gasoline rated at
87 octane or higher can be used,
but acceleration could be reduced,
and an audible knocking noise may
be heard. If the octane is less than
87, a heavy knocking noise may be
heard. If this occurs, use a gasoline
rated at 87 octane or higher as soon
as possible. Otherwise, the engine
could be damaged. If heavy
knocking is heard when using
gasoline with a higher octane rating,
the engine needs service.
Use of Seasonal Fuels
Use summer and winter fuels in the
appropriate season. Driving or
starting could be affected if the
incorrect fuel is used. Drive the
vehicle with the engine running until
the fuel is a half tank or less, then
refuel with the current seasonal fuel.
Prohibited Fuels
Gasolines containing oxygenates,
such as ethers and ethanol, as well
as reformulated gasolines are
available in some cities. If these
gasolines comply with the
previousely described specification,
then they are acceptable to use.
However, E85 (85% ethanol) and
other fuels containing more than
15% ethanol must be used only in
flex fuel vehicles.
{Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Some gasolines that are not
reformulated for low emissions can
contain an octane-enhancing
additive called
Page 340 of 544

Black plate (70,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-70 Driving and Operating
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use
gasolines with MMT as they can
reduce spark plug life and affect
emission control system
performance. The malfunction
indicator lamp may turn on. If this
occurs, see your dealer for service.
Gasoline Specifications
At a minimum, gasoline should meet
ASTM specification D 4814. Some
gasolines contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend
against the use of gasolines
containing MMT. See“Prohibited
Fuels" in Fuel on page 9-68.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance might
be affected. The malfunction
indicator lamp could turn on and the
vehicle may not pass a smog-check
test. See
Malfunction Indicator
Lamp on page 5-22. If this occurs,
return to your authorized dealer for
diagnosis. If it is determined that the
condition is caused by the type of
fuel used, repairs may not be
covered by the vehicle warranty.
Fuels in Foreign
Countries
If planning to drive in countries
outside the U.S. or Canada, the
proper fuel might be hard to find.
Check regional auto club or fuel
retail brand websites for availability
in the country where driving. Never
use leaded gasoline, fuel containing
methanol, or any other fuel not
recommended. Costly repairs caused by use of improper fuel
would not be covered by the vehicle
warranty.
Fuel Additives
To keep fuel systems clean, TOP
TIER Detergent Gasoline is
recommended. See
Fuel on
page 9-68.
If TOP TIER Detergent Gasoline is
not available, one bottle of Fuel
System Treatment PLUS, part
number 88861013, added to the fuel
tank at every engine oil change, can
help. Fuel System Treatment PLUS
is the only gasoline additive
recommended by General Motors.
It is available at your dealer.
Do not use additives with E85 or
FlexFuel.
E85 or FlexFuel
Vehicles with a yellow fuel cap can
use either unleaded gasoline or fuel
containing up to 85% ethanol (E85).
Page 341 of 544

Black plate (71,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-71
All other vehicles should use only
the unleaded gasoline as described
inFuel on page 9-68.
The use of E85 or FlexFuel is
encouraged when the vehicle is
designed to use it. E85 or FlexFuel
is made from renewable sources.
To help locate fuel stations that
carry E85 or FlexFuel, the U.S.
Department of Energy has an
alternative fuels website. See
www.afdc.energy.gov/afdc/locator/
stations.
E85 or FlexFuel should meet ASTM
Specification D 5798 or CAN/
CGSB–3.512 in Canada. Do not use
the fuel if the ethanol content is
greater than 85%. Fuel mixtures that
do not meet ASTM or CGSB
specifications can affect driveability
and could cause the malfunction
indicator lamp to come on.
After refueling, the vehicle
calculates the composition of the
fuel. It is not recommended to
repeatedly switch between fuels. If fuels are switched frequently, add
as much fuel as possible and do not
add less than 11 L (3 gal) when
refueling. Drive at least 11 km (7 mi)
immediately after refueling to allow
the vehicle to adapt to the change in
ethanol concentration.
Because E85 or FlexFuel has less
energy per liter (gallon) than
gasoline, the vehicle will need to be
refilled more often. See
Filling the
Tank on page 9-71.
{Caution
Some additives are not
compatible with E85 or FlexFuel
and can harm the vehicle's fuel
system. Do not add anything to
E85 or FlexFuel. Damage caused
by additives would not be covered
by the vehicle warranty.
{Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Filling the Tank
If the vehicle has a diesel engine,
see the Duramax diesel supplement
for more information.
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
.To help avoid injuries to you
and others, read and follow
all the instructions on the fuel
pump island.
(Continued)
Page 342 of 544

Black plate (72,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-72 Driving and Operating
Warning (Continued)
.Turn off the engine when
refueling.
.Keep sparks, flames, and
smoking materials away
from fuel.
.Do not leave the fuel pump
unattended.
.Do not reenter the vehicle
while pumping fuel.
.Keep children away from the
fuel pump and never let
children pump fuel.
.Fuel can spray out if the fuel
cap is opened too quickly.
This spray can happen if the
tank is nearly full, and is
more likely in hot weather.
Open the fuel cap slowly and
wait for any hiss noise to stop
then unscrew the cap all
the way
The fuel cap is behind a hinged fuel
door on the driver side of the
vehicle. Vehicles that have a
FlexFuel badge and a yellow fuel
cap can use either unleaded
gasoline or ethanol fuel containing
up to 85% ethanol (E85). SeeE85
or FlexFuel on page 9-70.
To remove the fuel cap, turn it
slowly counterclockwise.
If the vehicle is a dual fuel tank
chassis cab model, and it runs out
of fuel, refuel the front fuel tank first
to ensure a quick restart. Be careful not to spill fuel. Do not
top off or overfill the tank and wait a
few seconds after you have finished
pumping before removing the
nozzle. Clean fuel from painted
surfaces as soon as possible. See
Exterior Care on page 10-96.
When replacing the fuel cap, turn it
clockwise until it clicks. It will require
more effort to turn the fuel cap on
the last turn as you tighten it. Make
sure the cap is fully installed. The
diagnostic system can determine if
the fuel cap has been left off or
improperly installed. This would
allow fuel to evaporate into the
atmosphere. See
Malfunction
Indicator Lamp on page 5-22.
The TIGHTEN GAS CAP message
displays on the Driver Information
Center (DIC) if the fuel cap is not
properly installed. See Fuel System
Messages on page 5-38 for more
information.
Page 343 of 544

Black plate (73,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-73
{Warning
If a fire starts while you are
refueling, do not remove the
nozzle. Shut off the flow of fuel by
shutting off the pump or by
notifying the station attendant.
Leave the area immediately.
{Caution
If a new fuel cap is needed, be
sure to get the right type of cap
from your dealer. The wrong type
of fuel cap might not fit properly,
might cause the malfunction
indicator lamp to light, and could
damage the fuel tank and
emissions system. See
Malfunction Indicator Lamp on
page 5-22.
Filling a Portable Fuel
Container
{Warning
Filling a portable fuel container
while it is in the vehicle can cause
fuel vapors that can ignite either
by static electricity or other
means. You or others could be
badly burned and the vehicle
could be damaged. Always:
.Use approved fuel
containers.
.Remove the container from
the vehicle, trunk, or pickup
bed before filling.
.Place the container on the
ground.(Continued)
Warning (Continued)
.Place the nozzle inside the fill
opening of the container
before dispensing fuel, and
keep it in contact with the fill
opening until filling is
complete.
.Fill the container no more
than 95% full to allow for
expansion.
.Do not smoke, light matches,
or use lighters while
pumping fuel.
.Avoid using cell phones or
other electronic devices.
Page 344 of 544

Black plate (74,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-74 Driving and Operating
Trailer Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer. Read
the entire section before towing a
trailer.
For towing a disabled vehicle, see
Towing the Vehicle on page 10-93.
For towing the vehicle behind
another vehicle such as a motor
home, seeRecreational Vehicle
Towing on page 10-94.
Driving Characteristics
and Towing Tips
Driving with a Trailer
When towing a trailer:
.Become familiar with the state
and local laws that apply to
trailer towing.
.Do not tow a trailer during the
first 800 km (500 mi) to prevent
damage to the engine, axle,
or other parts.
.Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
.Vehicles can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts
too often under heavy loads and/
or hilly conditions.
.Turn off Park Assist when
towing.
{Warning
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
(Continued)
Warning (Continued)
When towing a trailer:
.Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
.Fully open the air outlets on
or under the instrument
panel.
.Also adjust the climate
control system to a setting
that brings in only outside air.
See“Climate Control
Systems” in the Index.
For more information about
Carbon Monoxide, see Engine
Exhaust on page 9-32.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.