brake system GMC SIERRA 2014 Owner's Guide

Black plate (52,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-52 Driving and Operating
Brakes
Antilock Brake
System (ABS)
This vehicle has ABS, an advanced
electronic braking system that helps
prevent a braking skid.
When the vehicle begins to drive
away, ABS checks itself.
A momentary motor or clicking noise
might be heard while this test is
going on, and it might even be
noticed that the brake pedal moves
a little. This is normal.
If there is a problem with ABS, this
warning light stays on. SeeAntilock
Brake System (ABS) Warning Light
on page 5-25. If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses that the wheels
are slowing down. If one of the
wheels is about to stop rolling, the
computer will separately work the
brakes at each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
you steer around the obstacle while
braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You might hear the ABS
pump or motor operating and feel
the brake pedal pulsate, but this is
normal.
Braking in Emergencies
ABS allows you to steer and brake
at the same time. In many
emergencies, steering can help
more than even the very best
braking.

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 (57,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-57
Press5to enable or disable HDC.
Vehicle speed must be below
50 km/h (31 mph).
The HDC light displays on the
instrument cluster when enabled.
HDC can maintain vehicle speeds
between 3 and 22 km/h (2 and
14 mph) on an incline greater than
or equal to a 10% grade. A blinking
HDC light indicates that the system
is actively applying the brakes to
maintain vehicle speed.
When HDC is set, that is the initial
set speed. It can be increased or
decreased by applying the
accelerator or brake pedal. This
adjusted speed becomes the new
set speed. HDC will remain enabled between
22 and 60 km/h (14 and 37 mph),
however vehicle speed cannot be
set or maintained in this range.
It will automatically disable if the
vehicle speed is above 80 km/h
(50 mph) or above 60 km/h
(37 mph) for at least 30 seconds.
5
must be pressed again to
re-enable HDC.
When enabled, if the vehicle is at a
speed above 22 km/h (14 mph) and
less than 60 km/h (37 mph), a DIC
message will display.
Locking Rear Axle
Vehicles with a locking rear axle can
give more traction on snow, mud,
ice, sand, or gravel. It works like a
standard axle most of the time, but
when traction is low, this feature will
allow the rear wheel with the most
traction to move the vehicle.
Cruise Control
{Warning
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. Do not use the
cruise control on winding roads or
in heavy traffic.
Cruise control can be dangerous
on slippery roads. On such roads,
fast changes in tire traction can
cause excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.
With cruise control a speed of about
40 km/h (25 mph) or more can be
maintained without keeping your
foot on the accelerator. Cruise
control does not work at speeds
below about 40 km/h (25 mph).
If the brakes are applied, the cruise
control disengages.

Black plate (59,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-59
Resuming a Set Speed
If the cruise control is set at a
desired speed and then the brakes
are applied, the cruise control is
disengaged without erasing the set
speed from memory.
Once the vehicle speed reaches
about 40 km/h (25 mph) or more,
press the +RES button briefly on the
steering wheel. The vehicle returns
to the previous set speed.
Increasing Speed While Using
Cruise Control
If the cruise control system is
already activated:
.Press and hold the +RES button
on the steering wheel until the
desired speed is reached, then
release it.
.To increase vehicle speed in
small increments, briefly press
the +RES button. Each time this
is done, the vehicle goes about
1.6 km/h (1 mph) faster.Reducing Speed While Using
Cruise Control
If the cruise control system is
already activated:
.Press and hold the SET–
button
on the steering wheel until the
desired lower speed is reached,
then release it.
.To slow down in small
increments, briefly press the
SET– button. Each time this is
done, the vehicle goes about
1.6 km/h (1 mph) slower.
Passing Another Vehicle While
Using Cruise Control
Use the accelerator pedal to
increase the vehicle speed. When
you take your foot off the pedal, the
vehicle will slow down to the
previous set cruise speed. While
pressing the accelerator pedal or
shortly following the release to
override cruise control, briefly
pressing the SET– button will result
in cruise control set to the current
vehicle speed. Using Cruise Control on Hills
How well the cruise control works
on hills depends on the vehicle
speed, the load, and the steepness
of the hills. When going up steep
hills, pressing the accelerator pedal
may be necessary to maintain
vehicle speed.
While going downhill:.Vehicles with a 6-speed
automatic transmission and a
gasoline engine have Cruise
Grade Braking to help maintain
driver selected speed.
Cruise Grade Braking is enabled
when the vehicle is started and
cruise control is active. It is not
enabled in Range Selection
Mode. It assists in maintaining
driver selected speed when
driving on downhill grades by
using the engine and
transmission to slow the vehicle.

Black plate (60,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-60 Driving and Operating
To disable and enable Cruise
Grade Braking for the current
ignition key cycle, press and
hold the Tow/Haul button for
five seconds. A DIC message
displays. SeeTransmission
Messages on page 5-42.
.Vehicles with a diesel engine
have Cruise Grade Braking
enabled when Tow/Haul Mode is
on, the exhaust brake is on,
or both are on.
For other forms of Grade Braking,
see Automatic Transmission on
page 9-33 ,Tow/Haul Mode on
page 9-38, and Hill Descent Control
(HDC) on page 9-56. Ending Cruise Control
There are three ways to end cruise
control:
.To disengage cruise control,
step lightly on the brake pedal.
.To disengage cruise control,
Press
*on the steering wheel.
.To turn off the cruise control,
press
5on the steering wheel.
Erasing Speed Memory
The cruise control set speed is
erased from memory by pressing
5
or if the ignition is turned off.
Driver Assistance
Systems
This vehicle may have features that
work together to help avoid crashes
or reduce crash damage while
driving, backing, and parking. Read
this entire section before using
these systems.
{Warning
Do not rely on the Driver
Assistance Systems. These
systems do not replace the need
for paying attention and driving
safely. You may not hear or feel
alerts or warnings provided by
these systems. Failure to use
proper care when driving may
result in injury, death, or vehicle
damage. See Defensive Driving
on page 9-3.
(Continued)

Black plate (61,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
Driving and Operating 9-61
Warning (Continued)
Under many conditions, these
systems will not:
.Detect children, pedestrians,
bicyclists, or animals.
.Detect vehicles or objects
outside the area monitored by
the system.
.Work at all driving speeds.
.Warn you or provide you with
enough time to avoid a crash.
.Work under poor visibility or
bad weather conditions.
.Work if the detection sensor
is not cleaned or is covered
by ice, snow, mud, or dirt.
Complete attention is always
required while driving, and you
should be ready to take action
and apply the brakes and/or steer
the vehicle to avoid crashes. Audible or Safety Alert Seat
Some driver assistance features
alert the driver of obstacles by
beeping. To change the volume of
the warning chime, see
“Comfort
and Convenience” underVehicle
Personalization on page 5-45.
If equipped with the Safety Alert
Seat, the driver seat cushion may
provide a vibrating pulse alert
instead of beeping. To change this,
see “Collision/Detection Systems”
under Vehicle Personalization on
page 5-45.
Assistance Systems for
Parking or Backing
When the vehicle is in R (Reverse),
the Rear Vision Camera (RVC) and
Rear Parking Assist may help the
driver to avoid a crash or to reduce
crash damage. Some models may
also have Front Parking Assist. The RVC and Rear Parking Assist
will not work properly if the tailgate
is down. If the tailgate is down, do
not use these systems.
When the vehicle is shifted into
R (Reverse), the RVC displays an
image of the area behind the vehicle
in the center stack display. The
previous screen displays when the
vehicle is shifted out of R (Reverse)
after a short delay. To return to the
previous screen sooner, press a
button on the infotainment system,
shift into P (Park), or reach a vehicle
speed of 8 km/h (5 mph).
{Warning
The RVC system does not display
children, pedestrians, bicyclists,
animals, or any other object
located outside the camera's field
of view, below the bumper,
or under the vehicle. Perceived
distances may be different from
actual distances. Do not back the
(Continued)

Black plate (64,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - CRC - 6/6/14
9-64 Driving and Operating
Disconnecting the Rear Vision
Camera (RVC)
The RVC must be disconnected if
the tailgate needs to be removed.
The RVC is disconnected by
removing the connector from the
electrical junction block mounted on
the left side of the cross member of
the vehicle frame. After
disconnecting, the cap mounted
next to the camera connector must
be relocated so that the open
terminals on the junction block are
covered.
Assistance Systems for
Driving
If equipped, when driving the
vehicle, Forward Collision Alert
(FCA) and Lane Departure Warning
(LDW) can help to avoid a crash or
reduce crash damage.
Forward Collision Alert
(FCA) System
If equipped, the FCA system may
help to avoid or reduce the harm
caused by front-end crashes. When
approaching a vehicle ahead too
quickly, FCA provides a red flashing
alert on the windshield and rapidly
beeps or pulses the driver seat.
FCA also lights an amber visual
alert if following another vehicle
much too closely.
FCA detects vehicles within a
distance of approximately 60 m
(197 ft) and operates at speeds
above 40 km/h (25 mph).
{Warning
FCA is a warning system and
does not apply the brakes. When
approaching a slower-moving or
stopped vehicle ahead too rapidly,
or when following a vehicle too
closely, FCA may not provide a(Continued)
Warning (Continued)
warning with enough time to help
avoid a crash. FCA does not warn
of pedestrians, animals, signs,
guardrails, bridges, construction
barrels, or other objects. Be ready
to take action and apply the
brakes. For more information, see
Defensive Driving on page 9-3.
FCA can be disabled with the FCA
steering wheel control.
Detecting the Vehicle Ahead
FCA warnings will not occur unless
the FCA system detects a vehicle
ahead. When a vehicle is detected
ahead, the vehicle ahead indicator
will display green. Vehicles may not