power steering GMC SIERRA 1500 2015 User Guide

Black plate (23,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Infotainment System 7-23
In general there are flexible ways to
speak commands for completing the
tasks. Most of them, except
destination entry and voice keypad,
can be completed in a single
command. If the task takes more
than one command to complete, the
first command would be to indicate
the kind of task that is to be
performed. The system replies with
prompts that lead through a dialog
to enter the necessary information.
Voice recognition can be used when
the ignition is on or when Retained
Accessory Power (RAP) is active.
SeeRetained Accessory Power
(RAP) on page 9-28.
Using Voice Recognition
Voice recognition becomes available
once the system has been
initialized. This begins when the
ignition is turned on. Initialization
may take a few moments. 1. Press
gon the steering wheel
control to activate voice
recognition, or select
gon the
infotainment screen on the
center stack.
.If voice recognition is
started from the steering
wheel control, the
instrument cluster displays
the selections and visual
dialog content.
.If voice recognition is
started from the
infotainment screen, the
selections and visual dialog
content are displayed on
both the center stack
display and the instrument
cluster display.
2. The audio system mutes and the system plays a prompt followed
by a beep. 3. Wait until after the beep
completes, then clearly speak
one of the commands described
in this section.
Press
gto interrupt any voice
recognition system prompt. For
example, if the prompt seems to
be taking too long to finish,
press
gagain and the beep
should happen right away.
There are two voice prompt modes
supported:
.Long verbal prompts: The longer
prompts provide more
information regarding the
supported actions.
.Short prompts: The short
prompts provide simple
instructions about what can be
stated.
If a command is not spoken, the
voice recognition system says a
help prompt.

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 (4,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-4 Driving and Operating
If the engine ever stops while the
vehicle is being driven, brake
normally but do not pump the
brakes. Doing so could make the
pedal harder to push down. If the
engine stops, there will be some
power brake assist but it will be
used when the brake is applied.
Once the power assist is used up, it
can take longer to stop and the
brake pedal will be harder to push.
Steering
Electric Power Steering (1500
Series)
If the vehicle has electric power
steering, it does not have power
steering fluid. Regular maintenance
is not required.
If power steering assist is lost due
to a system malfunction, the vehicle
can be steered, but may require
increased effort. See your dealer if
there is a problem.If the steering wheel is turned until it
reaches the end of its travel, and is
held in that position for an extended
period of time, power steering assist
may be reduced.
If the steering assist is used for an
extended period of time, power
assist may be reduced.
Normal use of the power steering
assist should return when the
system cools down.
See specific vehicle steering
messages under
Steering System
Messages on page 5-41.Hydraulic Power Steering
(2500/3500 Series)
If the vehicle has hydraulic power
steering, it may require
maintenance. See Power Steering
Fluid (1500 Series) on page 10-26
or Power Steering Fluid (2500/3500
Series) on page 10-26. If power steering assist is lost
because the engine stops or a
system malfunctions, the vehicle
can be steered but may require
increased effort.
See your dealer if there is a
problem.
{Caution
If the steering wheel is turned
until it reaches the end of its
travel, and is held in that position
for more than 15 seconds,
damage may occur to the power
steering system and there may be
loss of power steering assist.
Curve Tips
.Take curves at a reasonable
speed.
.Reduce speed before entering a
curve.
.Maintain a reasonable steady
speed through the curve.

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 (44,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-44 Driving and Operating
{Caution
Shifting the transmission into gear
before the requested mode
indicator light has stopped
flashing could damage the
transfer case.
6. Start the engine and shift the transmission to the desired gear.
Automatic Transfer Case
Use the transfer case knob next to
the steering wheel to shift into and
out of four-wheel drive.
Indicator lights display which setting
the transfer case is in. N (Neutral) is
indicated on the knob. The indicator
lights will display briefly when the
ignition is turned on and one will
stay on. If the lights display
momentarily when the ignition is in
ON/RUN, but none stay on, the
knob may have been turned while
the vehicle was off. To see the
indicator, turn the knob to another
position so that it matches the
actual transfer case setting. If no
lights display, take the vehicle to
your dealer for service. An indicator
light flashes while shifting the
transfer case and remains
illuminated when the shift is
complete.
If the transfer case cannot make a
requested shift, it will return to the
last chosen setting. Turn the knob
back to the previous transfer case
setting to see the indicator. The settings are:
N (Neutral):
Use only when the
vehicle needs to be towed. See
Recreational Vehicle Towing on
page 10-93 orTowing the Vehicle
on page 10-93.
2
m(Two-Wheel Drive High): Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy.
AUTO (Automatic Four-Wheel
Drive): Use when road surface
traction conditions are variable.
When driving in AUTO, the front
axle is engaged, and the vehicle's
power is sent to the front and rear
wheels automatically based on
driving conditions. This setting
provides slightly lower fuel economy
than 2
m.
Do not use AUTO mode to park on
a steep grade with poor traction
such as ice, snow, mud, or gravel.
In AUTO mode only the rear wheels
will hold the vehicle from sliding

Black plate (93,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-93
Trailer Brake Control Panel
1. Manual Trailer Brake ApplyLever
2. Trailer Gain Adjustment Buttons
The ITBC system has a control
panel on the instrument panel to the
left of the steering column. See
Instrument Panel on page 1-2. The
control panel allows adjustment to
the amount of output, referred to as
Trailer Gain, available to the trailer
brakes and allows manual
application of the trailer brakes. The
Trailer Brake Control Panel is used along with the Trailer Brake Display
Page on the Driver Information
Center (DIC) to adjust and display
power output to the trailer brakes.
Trailer Brake DIC Display Page
The ITBC system displays
messages in the DIC.
The display page indicates Trailer
Gain setting, power output to the
trailer brakes, trailer connection, and
system operational status.
To display the Trailer Brake Display
Page, do any of the following:.Scroll through the DIC menu
pages.
.Press a Trailer Gain button.
If the Trailer Brake Display Page
is not currently displayed, press
a Trailer Gain button to recall the
current Trailer Gain setting.
Each press and release of the
gain buttons will then change the
Trailer Gain setting.
.Activate the Manual Trailer
Brake Apply Lever.
TRAILER GAIN: This setting can be
adjusted from 0.0 to 10.0 with either
a trailer connected or disconnected.
To adjust the Trailer Gain, press one
of the Trailer Gain Adjustment
buttons. Press and hold a gain
button to continuously adjust the
Trailer Gain. To turn the output to
the trailer off, adjust the Trailer Gain
setting to 0.0 (zero).
TRAILER OUTPUT: This displays
anytime a trailer with electric brakes
is connected. Output to the trailer
brakes is based on the amount of
vehicle braking present and relative
to the Trailer Gain setting. Output is
displayed from 0 to 100% for each
gain setting.
The Trailer Output will indicate
“- - -
- - -” on the Trailer Brake Display
Page whenever the following occur:
.No trailer is connected.
.A trailer without electric brakes
is connected (no DIC message
will display).

Black plate (1,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-3
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-5
Engine Oil . . . . . . . . . . . . . . . . . . 10-10
Engine Oil Life System . . . . . 10-13
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-14
Engine Air Cleaner/Filter . . . . 10-17
Cooling System . . . . . . . . . . . . 10-19
Engine Coolant . . . . . . . . . . . . . 10-20
Engine Overheating . . . . . . . . 10-23
Overheated Engine Protection
Operating Mode . . . . . . . . . . . 10-25 Engine Fan . . . . . . . . . . . . . . . . . 10-25
Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . 10-26
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . 10-26
Washer Fluid . . . . . . . . . . . . . . . 10-27
Brakes . . . . . . . . . . . . . . . . . . . . . 10-28
Brake Fluid . . . . . . . . . . . . . . . . . 10-29
Battery . . . . . . . . . . . . . . . . . . . . . 10-30
Four-Wheel Drive . . . . . . . . . . . 10-31
Front Axle . . . . . . . . . . . . . . . . . . 10-32
Rear Axle . . . . . . . . . . . . . . . . . . 10-33
Noise Control System . . . . . . 10-34
Starter Switch Check . . . . . . . 10-35
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-35
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-35
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-36
Wiper Blade Replacement . . . . . . . . . . . . . . 10-36
Glass Replacement . . . . . . . . 10-37
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-37
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-37
Halogen Bulbs . . . . . . . . . . . . . . 10-37
LED Lighting . . . . . . . . . . . . . . . 10-37
Headlamps, Front Turn Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-38
Fog Lamps . . . . . . . . . . . . . . . . . 10-38
Taillamps (Chassis Cab Models) . . . . . . . . . . . . . . . . . . . 10-39
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-39
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . 10-40
License Plate Lamp . . . . . . . . 10-40
Replacement Bulbs . . . . . . . . . 10-40
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-41
Fuses . . . . . . . . . . . . . . . . . . . . . . 10-41
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-42
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . 10-46
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . 10-48

Black plate (10,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-10 Vehicle Care
1. Positive (+) Terminal. SeeJump
Starting on page 10-88.
2. Battery on page 10-30.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10-19.
4. Engine Air Cleaner/Filter on
page 10-17.
5. Automatic Transmission Dipstick. See “How to Check
Automatic Transmission Fluid”
under Automatic Transmission
Fluid on page 10-14.
6. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10-10.
7. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10-10.
8. Engine Cooling Fan (Out of View). See Cooling System on
page 10-19.
9. Remote Negative (–) Location. See Jump Starting on
page 10-88. 10. Power Steering Fluid
Reservoir. See Power Steering
Fluid (1500 Series) on
page 10-26 orPower Steering
Fluid (2500/3500 Series) on
page 10-26.
11. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10-27.
12. Brake Fluid Reservoir. See Brake Fluid on page 10-29.
13. Auxiliary Battery (If Equipped). SeeBattery on page 10-30.
14. Engine Compartment Fuse
Block on page 10-42.
If the vehicle has a diesel engine
and/or an Allison Transmission, see
the Duramax diesel supplement.Engine Oil
For diesel engine vehicles, see
“Engine Oil” in the Duramax diesel
supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
.Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
.Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10-13.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.

Black plate (26,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-26 Vehicle Care
increases as the clutch more fully
engages, so an increase in fan
noise may be heard. This is normal
and should not be mistaken as the
transmission slipping or making
extra shifts. It is merely the cooling
system functioning properly. The fan
will slow down when additional
cooling is not required and the
clutch disengages.
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer towing,
high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly. Thefans will change to low speed when
additional cooling is no longer
required.
The electric engine cooling fans
may run after the engine has been
turned. off. This is normal and no
service is required.
Power Steering Fluid
(1500 Series)
The vehicle has electric power
steering and does not use power
steering fluid.
Power Steering Fluid
(2500/3500 Series)
See
Engine Compartment Overview
on page 10-5 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
Wait for the power steering system
to cool, with the engine off, before
checking the fluid.
How to Check Power Steering
Fluid
To check the power steering fluid:
1. Turn the key off and let the
engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.