
Black plate (21,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
Driving and Operating 9-21
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 9-27.
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 9-42.{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 (22,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
9-22 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.
Ignition Positions
(Keyless Access)
The vehicle has an electronic
keyless ignition with pushbutton
start.
Pressing the button cycles it through
three modes: ACC/ACCESSORY,
ON/RUN/START, and Stopping the
Engine/OFF.
The transmitter must be in the
vehicle for the system to operate.
If the pushbutton start is not
working, the vehicle may be near a
strong radio antenna signal causing
interference to the Keyless Access
system. See Remote Keyless Entry
(RKE) System Operation (Keyless
Access) on page 2-7 orRemote
Keyless Entry (RKE) System
Operation (Key Access) on
page 2-5.
To shift out of P (Park), the vehicle
must be in ACC/ACCESSORY or
ON/RUN and the brake pedal must
be applied.

Black plate (23,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
Driving and Operating 9-23
Stopping the Engine/LOCK/
OFF (No Indicator Lights):When
the vehicle is stopped, press the
ENGINE START/STOP button once
to turn the engine off.
If the vehicle is in P (Park), the
ignition will turn off, and Retained
Accessory Power (RAP) will remain
active. See Retained Accessory
Power (RAP) on page 9-27.
If the vehicle is not in P (Park), the
ignition will return to ACC/
ACCESSORY and display the
message SHIFT TO PARK in the
Driver Information Center (DIC).
See Transmission Messages on
page 5-40. When the vehicle is
shifted into P (Park), the ignition
system will switch to OFF.
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.
The vehicle may have an electric
steering column lock. The lock is
activated when the vehicle is switched to OFF and either front
door is opened. A sound may be
heard as the lock actuates or
releases. The steering column lock
may not release with the wheels
turned off center. If this happens,
the vehicle may not start. Move the
steering wheel from left to right
while attempting to start the vehicle.
If this does not work, the vehicle
needs service.
The vehicle may have an electric
steering column lock. The lock is
activated when the vehicle is
switched to OFF and either front
door is opened. A sound may be
heard as the lock actuates or
releases. The steering column lock
may not release with the wheels
turned off center. If this happens,
the vehicle may not start. Move the
steering wheel from left to right
while attempting to start the vehicle.
If this does not work, the vehicle
needs service.
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 OFF. On vehicles with an
automatic transmission, the shift
lever must be in P (Park) to turn
the ignition switch to the OFF
position.
4. Set the parking brake. See Parking Brake on page 9-42.

Black plate (27,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
Driving and Operating 9-27
To Use the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap theelectrical cord. The cord is by
the left front fender, next to the
engine compartment fuse block.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{Warning
Plugging the cord into an
ungrounded outlet could cause an
electrical shock. Also, the wrong
kind of extension cord could
overheat and cause a fire. You
could be seriously injured. Plug
the cord into a properly grounded
three-prong 110-volt AC outlet.
If the cord will not reach, use a
heavy-duty three-prong extension
cord rated for at least 15 amps. 4. Before starting the engine, be
sure to unplug and store the
cord as it was before to keep it
away from moving engine parts.
If you do not, it could be
damaged.
The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Retained Accessory
Power (RAP)
The following vehicle accessories
can be used for up to 10 minutes
after the engine is turned off:
.Audio System
.Power Windows
.OnStar System (if equipped)
.Sunroof (if equipped)
.Accessory Power Outlets. The
console and center seat outlets
are RAP powered. These features work when the key
is in ON/RUN or ACC/
ACCESSORY. Once the key is
turned from ON/RUN to LOCK/OFF,
the windows and sunroof continue
to work up to 10 minutes until any
door is opened. The radio continues
to work for up to 10 minutes or until
the driver door is opened.
Shifting Into Park
{Warning
It can be 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. 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, use the steps
that follow. If the vehicle has a
four-wheel drive transfer case
(Continued)

Black plate (28,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
9-28 Driving and Operating
Warning (Continued)
with a N (Neutral) position, and
the transfer case is in N (Neutral),
the vehicle will be free to roll,
even if the shift lever is in
P (Park). Be sure the transfer
case is in a drive gear. If towing a
trailer, seeDriving Characteristics
and Towing Tips on page 9-74.
1. Hold the brake pedal down, then set the parking brake.
See Parking Brake on
page 9-42.
2. Move the shift lever into the P (Park) position by pulling the
shift lever toward you and
moving it up as far as it will go.
3. Be sure the transfer case is in a drive gear —not in N (Neutral).
4. Turn the ignition key to LOCK/OFF. 5. Remove the key and take it with
you. If you can leave the vehicle
with the ignition key in your
hand, the vehicle is in P (Park).
Leaving the Vehicle with the
Engine Running
{Warning
It can be dangerous to leave the
vehicle with the engine running.
The vehicle could move suddenly
if the shift lever is not fully in
P (Park) with the parking brake
firmly set.
If you have four-wheel drive and
the transfer case is in N (Neutral),
the vehicle will be free to roll,
even if the shift lever is in
P (Park). So be sure the transfer
case is in a drive gear —not in
N (Neutral).
(Continued)
Warning (Continued)
And, if you leave the vehicle with
the engine running, it could
overheat and even catch fire. You
or others could be injured. Do not
leave the vehicle with the engine
running unless you have to.
If you have to leave the vehicle with
the engine running, be sure the
vehicle is in P (Park) and the
parking brake is firmly set before
you leave it. After you move the shift
lever into P (Park), hold the regular
brake pedal down. Then, see if you
can move the shift lever away from
P (Park) without first pulling it toward
you. If you can, it means that the
shift lever was not fully locked into
P (Park).

Black plate (31,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
Driving and Operating 9-31
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 9-27
and Engine Exhaust on page 9-30.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9-74.
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.
See “Range Selection Mode” under
Manual Mode on page 9-34.
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 9-27.
{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 9-27 andDriving
Characteristics and Towing Tips
on page 9-74.

Black plate (32,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
9-32 Driving and Operating
{Warning
If you have four-wheel drive, the
vehicle will be free to roll—even
if the shift lever is in P (Park) —if
the transfer case is in N (Neutral).
So, be sure the transfer case is in
a drive gear, Two-Wheel Drive
High or Four-Wheel Drive High or
Four-Wheel Drive Low —not in
N (Neutral). See Shifting Into Park
on page 9-27.
R (Reverse): Use this gear to
back up.
{Caution
Shifting to R (Reverse) while the
vehicle is moving forward could
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Shift to
R (Reverse) only after the vehicle
is stopped. To rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission, see
If
the Vehicle Is Stuck on page 9-13.
N (Neutral): In this position, the
engine does not connect with the
wheels. To restart when you are
already moving, use N (Neutral)
only. Also, use N (Neutral) when the
vehicle is being towed.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift
into a drive gear while the engine
is running at high speed.
{Caution
Shifting out of P (Park) or
N (Neutral) with the engine
running at high speed may
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Be sure the
engine is not running at high
speed when shifting the vehicle.
D (Drive): This position is for
normal driving. It provides the best
fuel economy. If you need more
power for passing, and you are:
.Going less than about 55 km/h
(35 mph), push the accelerator
pedal about halfway down.
.Going about 55 km/h (35 mph) or
more, push the accelerator all
the way down.
By doing this, the vehicle shifts
down to the next gear and has
more power.

Black plate (35,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
Driving and Operating 9-35
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 9-35.
While using Range Selection Mode,
cruise control and the Tow/Haul
Mode can be used.
{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.
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.