2015 GMC SIERRA 1500 cruise control

Black plate (36,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-36 Driving and Operating
when driving on downhill grades by
using the engine and transmission
to slow the vehicle. The first time
the system engages for each
ignition key cycle, a DIC message
will be displayed. SeeTransmission
Messages on page 5-42.
To disable or enable Normal Mode
Grade Braking within the current
ignition key cycle, press and hold
the Tow/Haul button for
five seconds. When the button is
released, the requested mode
change is made. A DIC message
displays. See Transmission
Messages on page 5-42.
For other forms of grade braking,
see Tow/Haul Mode on page 9-37
and Cruise Control on page 9-53.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 to
M (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 (37,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-37
Gear before shifting from D
(Drive) to M (Manual Mode)6th 5th 4th 3rd 2nd 1st
Range after shifting from D
(Drive) to M (Manual Mode) M4 M4 M3 M2 M2 M1
Grade Braking is not available when
Range Selection Mode is active.
See Tow/Haul Mode on page 9-37.
While using Range Selection Mode,
cruise control and the Tow/Haul
Mode can be used.
If the vehicle has an exhaust brake,
it can also be used, but will not
automatically downshift the
transmission. See “Exhaust Brake”
in the Duramax diesel supplement.
{Caution
Spinning the tires or holding the
vehicle in one place on a hill
using only the accelerator pedal
may damage the transmission.
The repair will not be covered by
(Continued)
Caution (Continued)
the vehicle warranty. If you are
stuck, do not spin the tires. When
stopping on a hill, use the brakes
to hold the vehicle in place.
Low Traction Mode
Low Traction Mode assists in
vehicle acceleration when road
conditions are slippery, such as with
ice or snow. While the vehicle is at a
stop, select M2 using Range
Selection Mode. This will limit
torque to the wheels and help to
prevent the tires from spinning.
Tow/Haul Mode
Vehicles with an automatic
transmission have a Tow/Haul
Mode. The Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling. This provides
increased performance, vehicle
control, and enhanced transmission
and engine cooling when driving
down steep hills or mountain
grades, towing, or hauling heavy
loads.

Black plate (38,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-38 Driving and Operating
The selector button is on the end of
the shift lever. Turn the Tow/Haul
Mode on and off by pressing the
button. When the Tow/Haul Mode is
enabled, a light on the instrument
cluster will come on.
SeeTow/Haul Mode Light on
page 5-26 andHill and Mountain
Roads on page 9-12.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9-87.
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is
only enabled while the Tow/Haul
Mode is selected and the vehicle is
not in the Range Selection Mode.
See “Tow/Haul Mode” listed
previously and Manual Mode on
page 9-36. Tow/Haul Mode Grade
Braking assists in maintaining
desired vehicle speeds when driving
on downhill grades by using the
engine and transmission to slow the
vehicle. On vehicles with a gasoline engine,
to disable or enable Tow/Haul
Grade Braking within the current
ignition key cycle, press and hold
the Tow/Haul button for
five seconds. When the button is
released, the requested mode
change is made. A DIC message is
displayed. See
Transmission
Messages on page 5-42.
On vehicles with a diesel engine,
Tow/Haul Mode Grade Braking can
be enabled or disabled by pressing
the Tow/Haul Mode button. Use the
exhaust brake and Tow/Haul Mode
for maximum grade braking.
See Towing Equipment on
page 9-87.
For other forms of grade braking,
see Automatic Transmission on
page 9-33 andCruise Control on
page 9-53.
Drive Systems
Four-Wheel Drive
If equipped, four-wheel drive
engages the front axle for extra
traction. Read the appropriate
section for transfer case operation
before using.
{Caution
Driving on clean, dry pavement in
four-wheel drive for an extended
period of time may cause
premature wear on the system.
The damage would not be
covered by the vehicle warranty.
Driving on clean, dry pavement in
four-wheel drive may:
.Cause a vibration to be felt in
the steering system.
.Cause tires to wear faster.
.Make the transfer case harder to
shift, and cause it to run noisier.

Black plate (50,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-50 Driving and Operating
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 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 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. See
Trailer
Sway Control (TSC) on page 9-96.
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 (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.

Black plate (53,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-53
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 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.
If equipped with an Allison or
Hydra-Matic 6-speed automatic
transmission, see “Tow/Haul Mode
Grade Braking” underTow/Haul Mode on page 9-37
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 9-50. 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.
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.

Black plate (54,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-54 Driving and Operating
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 the SET− button on the steering wheel.
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 5-10.
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 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. For each
press, the vehicle goes about
1.6 km/h (1 mph) faster.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster on
page 5-10. 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
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. For each press,
the vehicle goes about 1.6 km/h
(1 mph) slower.

Black plate (55,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-55
The speedometer reading can be
displayed in either English or metric
units. SeeInstrument Cluster on
page 5-10. 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 5-42.
.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 9-37, and Hill Descent Control
(HDC) on page 9-52.
Ending Cruise Control
There are four ways to end cruise
control:
.Step lightly on the brake pedal.
.Press*.
.Shift the transmission to neutral.
.To turn off cruise control,
press
5.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
5is pressed
or the ignition is turned off.

Black plate (61,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-61
as needed. Cruise control may be
disengaged when the Collision Alert
occurs.
Tailgating Alert
The vehicle ahead indicator will
display amber when you are
following a vehicle ahead much too
closely.
Selecting the Alert Timing
The FCA control is on the steering
wheel. Press
[to set the FCA
timing to Far, Medium, Near, or Off.
The first button press shows the
current setting on the DIC.
Additional button presses will
change this setting. The chosen
setting will remain until it is changed
and will affect the timing of both the
Collision Alert and the Tailgating
Alert features. The timing of both
alerts will vary based on vehicle
speed. The faster the vehicle speed,
the farther away the alert will occur. Consider traffic and weather
conditions when selecting the alert
timing. The range of selectable alert
timing may not be appropriate for all
drivers and driving conditions.
Unnecessary Alerts
FCA may provide unnecessary
alerts for turning vehicles, vehicles
in other lanes, objects that are not
vehicles, or shadows. These alerts
are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to
operate properly, cleaning the
outside of the windshield in front of
the camera sensor on the back of
the rearview mirror, and cleaning the
front of the vehicle where radar
sensors are located, may correct
the issue.