2015 GMC SIERRA dic

Black plate (48,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-48 Driving and Operating
{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 9-68.
Brake Assist
The Brake Assist feature is
designed to assist the driver in
stopping or decreasing vehicle
speed in emergency driving
conditions. This feature 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.
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

Black plate (50,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-50 Driving and Operating
SeeIf the Vehicle Is Stuck on
page 9-14 and“Turning the
Systems Off and On” later in this
section.
When the transfer case (if equipped)
is in Four-Wheel Drive Low, the
stability system is automatically
disabled,
gcomes 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.
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 5-36. To turn TCS on again,

Black plate (51,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Driving and Operating 9-51
press and release thegbutton. 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 5-36.
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 9-87
orHill Start Assist (HSA)
on page 9-48.
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. Press
5to 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 the system is
actively applying the brakes to
maintain vehicle speed.
When HDC is activated, the initial
HDC speed is set to the current
driving speed. It can be increased or
decreased by applying the
accelerator or brake pedal. This
adjusted speed becomes the new
set speed.

Black plate (52,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-52 Driving and Operating
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.
5must 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. See Vehicle
Speed Messages on page 5-42.
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
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).
{Warning
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. Do not use
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. If equipped with an Allison or
Hydra-Matic 6-speed automatic
transmission, see
“Tow/Haul Mode
Grade Braking” underTow/Haul
Mode on page 9-39 for an
explanation of how cruise control
interacts with the Range Selection
Mode, Tow/Haul Mode, and Grade
Braking systems.
If the cruise control is being used
and the Traction Control System
(TCS) or StabiliTrak begins to limit
wheel spin, the cruise control will
automatically disengage. See
Traction Control/Electronic Stability
Control on page 9-49. If a collision
alert occurs when cruise control is
activated, cruise control is
disengaged. See Forward Collision
Alert (FCA) System on page 9-59.
When road conditions allow you to
safely use it again, cruise control
can be turned back on.
If the brakes are applied, the cruise
control disengages.

Black plate (53,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Driving and Operating 9-53
5(On/Off):Press to turn the
system on or off. A white indicator
comes on in the instrument cluster
when cruise control is on and turns
off when cruise control is off.
+RES (Resume/Accelerate): If
there is a set speed in memory,
press briefly to resume to that
speed or press and hold to
accelerate. If cruise control is
already active, use to increase
vehicle speed. SET−
(Set/Coast): Press briefly to
set the speed and activate cruise
control. If cruise control is already
active, use to decrease vehicle
speed.
*(Cancel): Press to disengage
cruise control without erasing the
set speed from memory.
Setting Cruise Control
If
5is on when not in use, SET− or
+RES could get pressed and go into
cruise when not desired. Keep
5
off when cruise is not being used.
1. Press
5to turn the cruise
system on.
2. Get up to the desired speed.
3. Press and release SET−.
4. Remove foot from the accelerator.
The cruise control indicator on the
instrument cluster turns green after
cruise control has been set to the
desired speed. SeeInstrument
Cluster on page 5-9. Resuming a Set Speed
If the cruise control is set at a
desired speed and then the brakes
are applied or
*is pressed, 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. 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
until the desired speed is
reached, then release it.
.To increase vehicle speed in
small increments, briefly press
the +RES button. For each
press, the vehicle goes about
1.6 km/h (1 mph) faster.

Black plate (54,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-54 Driving and Operating
The speedometer reading can be
displayed in either English or metric
units. SeeInstrument Cluster on
page 5-9. The increment value used
depends on the units displayed.
Reducing Speed While Using
Cruise Control
If the cruise control system is
already activated:
.Press and hold the SET– button
until the desired lower speed is
reached, then release it.
.To slow down in small
increments, briefly press the
SET– button. For each press,
the vehicle goes about 1.6 km/h
(1 mph) slower.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster on
page 5-9. The increment value used
depends on the units displayed. 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.
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. See
Transmission
Messages on page 5-39.
.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.

Black plate (58,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-58 Driving and Operating
The instrument cluster may have a
parking assist display with bars that
show“distance to object” and object
location information for RPA, and on
some vehicles, for FPA. As the
object gets closer, more bars light
up and the bars change color from
yellow to amber to red.
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 FPA are higher
pitched than for RPA.
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
“Park Assist” underVehicle
Personalization on page 5-42. If the
parking assist is turned off through
vehicle personalization, the parking
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 parking assist
symbols or guidance lines, see
“Rear Camera”
underVehicle
Personalization on page 5-42.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.

Black plate (59,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Driving and Operating 9-59
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
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
be detected on curves, highway exit
ramps, or hills; or due to poor
visibility. FCA will not detect another
vehicle ahead until it is completely
in the driving lane.
{Warning
FCA does not provide a warning
to help avoid a crash, unless it
detects a vehicle. FCA may not
detect a vehicle ahead if the FCA
sensor is blocked by dirt, snow, (Continued)