2015 GMC SIERRA 1500 automatic transmission

Black plate (49,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Instruments and Controls 5-49
Power Door Locks
Select and the following may
display:
.Unlocked Door Anti-Lockout
.Auto Door Unlock
.Delayed Door Lock
Unlocked Door Anti-Lockout
When on, this feature will keep the
driver door from locking when the
door is open. If Off is selected, the
Delayed Door Lock menu will be
available.
Select Off or On.
Auto Door Unlock
This allows selection of which of the
doors will automatically unlock when
the vehicle is shifted into P (Park)
with an automatic transmission or
when the vehicle is turned off with a
manual transmission.
Select Off, All Doors, or Driver Door. Delayed Door Lock
When on, this feature will delay the
locking of the doors. To override the
delay, press the power door lock
switch on the door.
Select Off or On.
Remote Lock, Unlock, Start
Select and the following may
display:
.Remote Unlock Light Feedback
.Remote Lock Feedback
.Remote Door Unlock
.Remote Start Auto Cool Seats
.Remote Start Auto Heat Seats
.Passive Door Unlock
.Passive Door Lock
.Remote Left in Vehicle Alert
Remote Unlock Light Feedback
When on, the exterior lamps will
flash when unlocking the vehicle
with the RKE transmitter.
Select Off or Flash Lights. Remote Lock Feedback
This allows selection of what type of
feedback is given when locking the
vehicle with the RKE transmitter.
Select Off, Lights and Horn, Lights
Only, or Horn Only.
Remote Door Unlock
This allows selection of which doors
will unlock when pressing
Kon the
RKE transmitter.
Select All Doors or Driver Door.
Remote Start Auto Cool Seats
If equipped and turned on, this
feature will turn the cooled seats on
when using remote start on
warm days.
Select Off or On.
Remote Start Auto Heat Seats
If equipped and turned on, this
feature will turn the heated seats on
when using remote start on
cold days.
Select Off or On.

Black plate (3,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Lighting 6-3
When the high beams are on, this
indicator light on the instrument
cluster will also be on.
Flash-to-Pass
This feature lets you use the
high-beam headlamps to signal a
driver in front of you that you want
to pass. It works even if the
headlamps are in the automatic
position.
To use it, pull the turn signal lever
toward you, then release it.
If the headlamps are in the
automatic position or on low beam,
the high-beam headlamps will turn
on. They will stay on as long as you
hold the lever toward you. The
high-beam indicator on the
instrument cluster will come on.
Release the lever to return to
normal operation.
Daytime Running
Lamps (DRL)
DRL can make it easier for others to
see the front of the vehicle during
the day. Fully functional DRL are
required on all vehicles first sold in
Canada.
The DRL system comes on when
the following conditions are met:
.The ignition is on.
.The exterior lamp control is
in AUTO.
.The transmission is not in
P (Park).
.The light sensor determines it is
daytime.
When the DRL system is on, only
the DRL are on. The taillamps,
sidemarker lamps, instrument panel
lights, and other lamps will not
be on.
When it begins to get dark, the
automatic headlamp system
switches from DRL to the
headlamps. To turn off the DRL, turn the exterior
lamp control to the off position and
then release. For vehicles first sold
in Canada, off will only work when
the vehicle is in P (Park).
Automatic Headlamp
System
When the exterior lamp control is
set to AUTO and it is dark enough
outside, the headlamps come on
automatically.
There is a light sensor on top of the
instrument panel. Do not cover the
sensor, otherwise the headlamps
will come on when they are not
needed.

Black plate (1,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-1
Driving and
Operating
Driving Information
Distracted Driving . . . . . . . . . . . . . 9-2
Defensive Driving . . . . . . . . . . . . . 9-3
Drunk Driving . . . . . . . . . . . . . . . . . 9-3
Control of a Vehicle . . . . . . . . . . . 9-3
Braking . . . . . . . . . . . . . . . . . . . . . . . 9-3
Steering . . . . . . . . . . . . . . . . . . . . . . . 9-4
Off-Road Recovery . . . . . . . . . . . . 9-5
Loss of Control . . . . . . . . . . . . . . . . 9-5
Off-Road Driving . . . . . . . . . . . . . . 9-6
Driving on Wet Roads . . . . . . . . 9-11
Hill and Mountain Roads . . . . . 9-12
Winter Driving . . . . . . . . . . . . . . . 9-12
If the Vehicle Is Stuck . . . . . . . . 9-14
Vehicle Load Limits . . . . . . . . . . 9-15
Truck-Camper LoadingInformation . . . . . . . . . . . . . . . . . 9-21
Starting and Operating
New Vehicle Break-In . . . . . . . . 9-23
Adjustable Throttle and BrakePedal . . . . . . . . . . . . . . . . . . . . . . . 9-24
Ignition Positions . . . . . . . . . . . . 9-24
Starting the Engine . . . . . . . . . . 9-26 Fast Idle System . . . . . . . . . . . . . 9-27
Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . 9-28
Engine Coolant Heater . . . . . . . 9-28
Shifting Into Park . . . . . . . . . . . . 9-29
Shifting out of Park . . . . . . . . . . 9-31
Parking over Things That Burn . . . . . . . . . . . . . . . . . . 9-31
Active Fuel Management
®. . . 9-31
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . 9-32
Running the Vehicle While Parked . . . . . . . . . . . . . . . . . . . . . 9-33
Automatic Transmission
Automatic Transmission . . . . . 9-33
Manual Mode . . . . . . . . . . . . . . . . 9-36
Tow/Haul Mode . . . . . . . . . . . . . . 9-37
Drive Systems
Four-Wheel Drive . . . . . . . . . . . . 9-38
Brakes
Antilock BrakeSystem (ABS) . . . . . . . . . . . . . . 9-47
Parking Brake . . . . . . . . . . . . . . . 9-48
Brake Assist . . . . . . . . . . . . . . . . . 9-49
Hill Start Assist (HSA) . . . . . . . 9-49
Ride Control Systems
Traction Control/Electronic Stability Control . . . . . . . . . . . . 9-50
Hill Descent Control (HDC) . . . . . . . . . . . . . . 9-52
Locking Rear Axle . . . . . . . . . . . 9-52
Cruise Control
Cruise Control . . . . . . . . . . . . . . . 9-53
Driver Assistance Systems
Driver Assistance
Systems . . . . . . . . . . . . . . . . . . . . 9-56
Assistance Systems for Parking or Backing . . . . . . . . . 9-56
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . 9-59
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . 9-59
Lane Departure Warning (LDW) . . . . . . . . . . . . . 9-62
Fuel
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . 9-64
California FuelRequirements . . . . . . . . . . . . . . 9-65
Fuels in Foreign Countries . . . 9-65
Fuel Additives . . . . . . . . . . . . . . . 9-65

Black plate (8,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-8 Driving and Operating
cannot be seen, get out of the
vehicle and walk the hill before
driving further.
When driving on hills:
.Use a low gear and keep a firm
grip on the steering wheel.
.Maintain a slow speed.
.When possible, drive straight up
or down the hill.
.Slow down when approaching
the top of the hill.
.Use headlamps even during the
day to make the vehicle more
visible.
{Warning
Driving to the top of a hill at high
speed can cause an accident.
There could be a drop-off,
embankment, cliff, or even
another vehicle. You could be
seriously injured or killed. As you
near the top of a hill, slow down
and stay alert.
.Never go downhill forward or
backward with either the
transmission or transfer case in
N (Neutral). The brakes could
overheat and you could lose
control.
{Warning
If the vehicle has the two‐speed
automatic transfer case, shifting
the transfer case to N (Neutral)
can cause your vehicle to roll
even if the transmission is in
P (Park). This is because the
N (Neutral) position on the
transfer case overrides the
transmission. You or someone
else could be injured. If leaving
the vehicle, set the parking brake
and shift the transmission to
P (Park). Shift the transfer case to
any position but N (Neutral).
.When driving down a hill, keep
the vehicle headed straight
down. Use a low gear because
the engine will work with thebrakes to slow the vehicle and
help keep the vehicle under
control.
{Warning
Heavy braking when going down
a hill can cause your brakes to
overheat and fade. This could
cause loss of control and you or
others could be injured or killed.
Apply the brakes lightly when
descending a hill and use a low
gear to keep vehicle speed under
control.
If the vehicle stalls on a hill:
1. Apply the brakes to stop the vehicle, and then apply the
parking brake.

Black plate (25,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-25
To shift out of P (Park), the ignition
must be in ON/RUN or ACC/
ACCESSORY and the regular brake
pedal must be applied.
1 (STOPPING THE ENGINE/LOCK/
OFF):When the vehicle is stopped,
turn the ignition switch to LOCK/
OFF to turn the engine off. Retained
Accessory Power (RAP) will remain
active. See Retained Accessory
Power (RAP) on page 9-28.
This position locks the ignition and
steering wheel. It also locks the
transmission on automatic
transmission vehicles. The key can
be removed in LOCK/OFF.
The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
does not work, then the vehicle
needs service. Do not turn the engine off when the
vehicle is moving. This will cause a
loss of power assist in the brake
and steering systems and disable
the airbags.
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steady
pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral). This can be done while the
vehicle is moving. After shifting
to N (Neutral), firmly apply the
brakes and steer the vehicle to a
safe location.
3. Come to a complete stop, shift to P (Park), and turn the ignition
to LOCK/OFF. On vehicles with
an automatic transmission, the
shift lever must be in P (Park) to
turn the ignition switch to the
LOCK/OFF position. 4. Set the parking brake. See
Parking Brake on page 9-48.
{Warning
Turning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, only shut the
vehicle off in an emergency.
If the vehicle cannot be pulled over,
and must be shut off while driving,
turn the ignition to ACC/
ACCESSORY.
{Caution
Using a tool to force the key to
turn in the ignition could cause
damage to the switch or break the
key. Use the correct key, make
sure it is all the way in, and turn it
only with your hand. If the key
cannot be turned by hand, see
your dealer.

Black plate (26,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-26 Driving and Operating
2 (ACC/ACCESSORY):This
position lets things like the radio
and the windshield wipers operate
while the engine is off. It also
unlocks the steering wheel. Use this
position if the vehicle must be
pushed or towed.
3 (ON/RUN): This position can be
used to operate the electrical
accessories and to display some
instrument cluster warning and
indicator lights. This position can
also be used for service and
diagnostics, and to verify the proper
operation of the malfunction
indicator lamp as may be required
for emission inspection purposes.
The switch stays in this position
when the engine is running. The
transmission is also unlocked in this
position on automatic transmission
vehicles.
If the key is left in the ACC/
ACCESSORY or ON/RUN position
with the engine off, the battery could
be drained. The vehicle may not
start if the battery is allowed to drain
for an extended period of time. 4 (START):
This is the position that
starts the engine. When the engine
starts, release the key. The ignition
switch returns to ON/RUN for
driving.
A warning tone will sound when the
driver door is opened and the
ignition is in ACC/ACCESSORY or
LOCK/OFF, and the key is in the
ignition.
Starting the Engine
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
{Caution
If you add electrical parts or
accessories, you could change
the way the engine operates. Any
resulting damage would not be
covered by the vehicle warranty.
See Add-On Electrical Equipment
on page 9-97.
{Caution
If the steering wheel is turned
until it reaches the end of its
travel, and is held in that position
while starting the vehicle, damage
may occur to the hydraulic power
steering system and there may be
loss of power steering assist.
Move the shift lever to P (Park) or
N (Neutral). To restart the engine
when the vehicle is already moving,
use N (Neutral) only.
{Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.

Black plate (33,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-33
Running the Vehicle
While Parked
It is better not to park with the
engine running.
If the vehicle is left with the engine
running, follow the proper steps to
be sure the vehicle will not move.
SeeShifting Into Park on page 9-29
and Engine Exhaust on page 9-32.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9-69.
Automatic
Transmission
If equipped, there is an electronic
shift lever position indicator within
the instrument cluster. This display
comes on when the ignition key is
turned to the ON/RUN position.
There are several different positions
for the shift lever.
Heavy-Duty 6-Speed Automatic
Transmission Shown, Light-Duty
6-Speed Similar
See “Range Selection Mode” under
Manual Mode on page 9-36.
P (Park): This position locks the
rear wheels. It is the best position to
use when starting the engine
because the vehicle cannot move
easily. When parked on a hill, especially when the vehicle has a
heavy load, you might notice an
increase in the effort to shift out of
P (Park). See
“Torque Lock” under
Shifting Into Park on page 9-29.
{Warning
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running. If you have left
the engine running, the vehicle
can move suddenly. You or others
could be injured. To be sure the
vehicle will not move, even when
you are on fairly level ground,
always set the parking brake and
move the shift lever to P (Park).
See Shifting Into Park on
page 9-29 andDriving
Characteristics and Towing Tips
on page 9-69.

Black plate (35,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-35
Use D (Drive) and Tow/Haul Mode
when towing a trailer, carrying a
heavy load, driving on steep hills,
or driving off-road. Shift the
transmission to a lower gear
selection if the transmission shifts
too often.
Downshifting the transmission in
slippery road conditions could result
in skidding. See“Skidding”under
Loss of Control on page 9-5.
The vehicle has a shift stabilization
feature that adjusts the transmission
shifting to the current driving
conditions in order to reduce rapid
upshifts and downshifts. This shift
stabilization feature is designed to
determine, before making an
upshift, if the engine is able to
maintain vehicle speed by analyzing
things such as vehicle speed,
throttle position, and vehicle load.
If the shift stabilization feature
determines that a current vehicle
speed cannot be maintained, the
transmission does not upshift and
instead holds the current gear. In some cases, this could appear to
be a delayed shift, however the
transmission is operating normally.
The transmission uses adaptive
shift controls. The adaptive shift
control process continually
compares key shift parameters to
pre-programmed ideal shifts stored
in the transmission’s computer. The
transmission constantly makes
adjustments to improve vehicle
performance according to how the
vehicle is being used, such as with
a heavy load or when the
temperature changes. During this
adaptive shift control process,
shifting might feel different as the
transmission determines the best
settings.
When temperatures are very cold,
the transmission's gear shifting
could be delayed providing more
stable shifts until the engine warms
up. Shifts could be more noticeable
with a cold transmission. This
difference in shifting is normal.
M (Manual Mode):
This position
allows selection of a range of gears
appropriate for current driving
conditions. If equipped, see “Range
Selection Mode” underManual
Mode on page 9-36.
{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
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.
Normal Mode Grade Braking
If equipped with a gasoline engine
and an automatic transmission,
Normal Mode Grade Braking is
enabled when the vehicle is started,
but is not enabled in Range
Selection Mode. It assists in
maintaining desired vehicle speeds