Trailer GMC SIERRA 2014 Owner's Guide

Black plate (37,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-37
Manual Mode
Range Selection Mode
If equipped, Range Selection Mode
helps control the vehicle's
transmission and vehicle speed
while driving downhill or towing a
trailer by letting you select a desired
range of gears.
To use this feature:
1. Move the shift lever toM (Manual Mode).
2. Press the plus/minus buttons on the shift lever to select the
desired range of gears for
current driving conditions. When the shift lever is moved from
D (Drive) to M (Manual Mode), a
number displays next to the M,
indicating the current transmission
range.
This number is the highest gear that
the transmission will command while
operating in M (Manual Mode).
All gears below that number are
available. As driving conditions
change, the transmission can
automatically shift to lower gears.
For example, when M5 is selected,
1 (First) through 5 (Fifth) gears are
automatically shifted by the
transmission, but 6 (Sixth) cannot
be used until the plus/minus button
on the shift lever is used to change
to the range.
In vehicles with gasoline engines,
when the shift lever is moved from
D (Drive) to M (Manual Mode), a
downshift may occur. The gear that
the transmission is operating in
when the shift lever is moved from
D (Drive) to M (Manual Mode)
determines if a downshift occurs.
See the following chart.

Black plate (53,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-53
Parking Brake
Set the parking brake by holding the
regular brake pedal down, then
pushing down the parking brake
pedal.
If the ignition is on, the brake
system warning light will come on.
SeeBrake System Warning Light on
page 5-24.
{Caution
Driving with the parking brake on
can overheat the brake system
and cause premature wear or
damage to brake system parts.
Make sure that the parking brake
is fully released and the brake
warning light is off before driving.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the parking brake pedal.
If the parking brake is not released
when you begin to drive, the brake
system warning light will flash and a
chime will sound warning you that
the parking brake is still on.
If you are towing a trailer and are
parking on a hill, see Driving
Characteristics and Towing Tips on
page 9-74.
Brake Assist
This vehicle has a brake assist
feature designed to assist the driver
in stopping or decreasing vehicle
speed in emergency driving
conditions. This feature
automatically uses the stability
system hydraulic brake control
module to supplement the power
brake system under conditions
where the driver has quickly and
forcefully applied the brake pedal in
an attempt to quickly stop or slow
down the vehicle. The stability
system hydraulic brake control
module increases brake pressure at
each corner of the vehicle until the
ABS activates. Minor brake pedal
pulsation or pedal movement during
this time is normal and the driver
should continue to apply the brake
pedal as the driving situation
dictates. The brake assist feature
will automatically disengage when
the brake pedal is released or brake
pedal pressure is quickly
decreased.

Black plate (54,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-54 Driving and Operating
Hill Start Assist (HSA)
This vehicle has an HSA feature,
which may be useful when the
vehicle is stopped on a grade. This
feature is designed to prevent the
vehicle from rolling, either forward or
rearward, during vehicle drive off.
After you completely stop and hold
the vehicle in a complete standstill
on a grade, HSA will automatically
activate. During the transition period
between when you release the
brake pedal and start to accelerate
to drive off on a grade, HSA holds
the braking pressure for a maximum
of two seconds to ensure that there
is no rolling. The brakes will
automatically release when the
accelerator pedal is applied within
the two-second window.If the vehicle is equipped with the
Integrated Trailer Brake Control
(ITBC) system, HSA may also apply
the trailer brakes. It will not activate
if the vehicle is in a drive gear and
facing downhill or if the vehicle is
facing uphill and in R (Reverse).
There may be situations on minor
hills (less than 5% grade) with a
loaded vehicle or while pulling a
trailer where HSA will not activate.
If you release the brake pedal and
then reapply the brake pedal while
HSA is activated, the brake pedal
typically feels firmer with less pedal
travel.
Ride Control Systems
Traction Control/
Electronic Stability
Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak®, an
electronic stability control system.
These systems help limit wheel spin
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any
of the drive wheels are spinning or
beginning to lose traction. When this
happens, TCS applies the brakes to
the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak selectively applies
braking pressure to any one of the

Black plate (55,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-55
vehicle wheel brakes to assist the
driver in keeping the vehicle on the
intended path. Trailer Sway Control
(TSC) is also on automatically when
the vehicle is started. SeeTrailer
Sway Control (TSC) on page 9-98.
If cruise control is being used and
traction control or StabiliTrak begins
to limit wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road
conditions allow.
Both systems come on
automatically when the vehicle is
started and begins to move. The
systems may be heard or felt while
they are operating or while
performing diagnostic checks. This
is normal and does not mean there
is a problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary
to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow.
See If the Vehicle Is Stuck on page 9-14
and“Turning the
Systems Off and On” later in this
section.
When the transfer case is in
Four-Wheel Drive Low, the stability
system is automatically disabled,
the StabiliTrak OFF light comes on,
and the appropriate message will
appear on the DIC. Both traction
control and StabiliTrak are
automatically disabled in this
condition.
The indicator light for both systems
is in the instrument cluster. This
light will:
.Flash when TCS is limiting
wheel spin.
.Flash when StabiliTrak is
activated.
.Turn on and stay on when either
system is not working.
If either system fails to turn on or to
activate, a message displays in the
Driver Information Center (DIC), and
dcomes on and stays on to
indicate that the system is inactive
and is not assisting the driver in
maintaining control. The vehicle is
safe to drive, but driving should be
adjusted accordingly.
If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.
Drive the vehicle. If
dcomes on
and stays on, the vehicle may need
more time to diagnose the problem.
If the condition persists, see your
dealer.

Black plate (56,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-56 Driving and Operating
Turning the Systems Off
and On
The button for TCS and StabiliTrak
is on the center stack.
{Caution
Do not repeatedly brake or
accelerate heavily when TCS is
off. The vehicle driveline could be
damaged.
To turn off only TCS, press and
release the
gbutton. The traction
off light
idisplays in the instrument
cluster. The appropriate message
will display in the DIC. See Ride
Control System Messages on
page 5-40. To turn TCS on again, press and release the
gbutton. The
traction off light
idisplayed in the
instrument cluster will turn off.
If TCS is limiting wheel spin when
the
gbutton is pressed, the system
will not turn off until the wheels stop
spinning.
To turn off both TCS and StabiliTrak,
press and hold the
gbutton until
the traction off light
iand the
StabiliTrak OFF light
gcome on
and stay on in the instrument
cluster, then release. The
appropriate message will display in
the DIC. See Ride Control System
Messages on page 5-40.
To turn TCS and StabiliTrak on
again, press and release the
g
button. The traction off lightiand
the StabiliTrak OFF light
gin the
instrument cluster turn off. StabiliTrak will automatically turn on
if the vehicle exceeds 56 km/h
(35 mph). Traction control will
remain off.
The vehicle has a Trailer Sway
Control (TSC) feature and a Hill
Start Assist (HSA) feature. See
Trailer Sway Control (TSC) on
page 9-98
orHill Start Assist (HSA)
on page 9-54.
Adding accessories can affect the
vehicle performance. See
Accessories and Modifications on
page 10-3.
Hill Descent
Control (HDC)
If equipped, HDC can be used when
driving downhill. It sets and
maintains vehicle speed while
descending a very steep incline in a
forward or reverse gear.
The HDC switch is on the center
stack, below the climate controls.

Black plate (63,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-63
The vehicle may have an instrument
cluster parking assist display with
bars that show“distance to object”
and object location information for
URPA, and on some vehicles, for
the Front Parking Assist system. As
the object gets closer, more bars
light up.
When an object is first detected in
the rear, one beep will be heard
from the rear, or both sides of the
Safety Alert Seat will pulse two
times. When an object is very close
(<0.6 m (2 ft) in the vehicle rear,
or <0.3 m (1 ft) in the vehicle front),
a continuous beep will sound from the front or rear, or both sides of the
Safety Alert Seat will pulse five
times. Beeps for Front Parking
Assist are higher pitched than for
Rear Parking Assist.
Turning the Features On or Off
TheXbutton on the center stack
is used to turn on or off the Front
and Rear Parking Assist. The
indicator light in the button comes
on when the features are on and
turns off when the features have
been disabled.
Front and Rear Parking Assist can
be turned off, on, or on with towbar
through vehicle personalization. See
“Parking Assist” underVehicle
Personalization on page 5-45. If the
parking assist is turned off through
vehicle personalization, the park assist button on the center stack will
be disabled. To turn the parking
assist on again, select On in the
vehicle personalization menu. The
On with Towbar setting allows for
the parking assist to work properly
with a small item attached to the
trailer hitch. Turn off parking assist
when towing a trailer.
To turn the Rear Vision Camera
(RVC) system rear parking assist
symbols or guidance lines on or off:
1. On the infotainment system
Home screen, press the Settings
screen button, or turn the MENU
knob to highlight Settings and
press MENU.
2. Select Rear Camera.
3. Press Rear Park Assist Symbols or Guidance Lines and then
select Off or On.

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.

Black plate (75,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-75
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
Passing
More passing distance is needed
when towing a trailer. The
combination will not accelerate as
quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
{Caution
Making very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance. If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a lower
gear
before starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.
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.
The Tow/Haul Mode may be used if
the transmission shifts too often.
See Tow/Haul Mode on page 9-38.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off

Black plate (76,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-76 Driving and Operating
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine
off. If the overheat warning comes
on, seeEngine Overheating on
page 10-23.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface. If parking the rig on a hill:
1. Press the brake pedal, but do
not shift into P (Park) yet. Turn
the wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake. 5. Let up on the brake pedal.
6. Drive slowly until the trailer is
clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11-3. 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.

Black plate (77,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-77
Trailer Towing
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
If the vehicle is bi-fuel, see the
bi-fuel supplement.
Do not tow a trailer during break-in.
SeeNew Vehicle Break-In on
page 9-23.
{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, the brakes may not work
well or even at all. 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.
(Continued)
Warning (Continued)
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.
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.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. Read this section
carefully before pulling a trailer.