Page 217 of 427

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
216 Driving and Operating
Warning (Continued)
.Do not leave a seat
folded down unless you
need to.
There is also important loading
information for off-road driving in
this manual. See “Loading Your
Vehicle for Off-Road Driving”
under Off-Road Driving 0203.
Starting and
Operating
New Vehicle Break-In
Caution
The vehicle does not need an
elaborate break-in. But it will
perform better in the long run if
you follow these guidelines:
. Keep the vehicle speed at
88 km/h (55 mph) or less for
the first 805 km (500 mi).
. Do not drive at any one
constant speed, fast or slow,
for the first 805 km (500 mi).
Do not make full-throttle
starts. Avoid downshifting to
brake or slow the vehicle.
. Avoid making hard stops for
the first 322 km (200 mi) or
so. During this time the new
brake linings are not yet
broken in. Hard stops with
new linings can mean
(Continued)
Caution (Continued)
premature wear and earlier
replacement. Follow this
breaking-in guideline every
time you get new brake
linings.
. Do not tow a trailer during
break-in. See Trailer Towing
0 271 for the trailer towing
capabilities of the vehicle
and more information.
Following break-in, engine speed
and load can be gradually
increased.
Adjustable Throttle and
Brake Pedal
If equipped, the position of the
throttle and brake pedals can be
changed.
The pedals can only be adjusted
when the vehicle is in P (Park).
Page 218 of 427

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Driving and Operating 217
The switch used to adjust the
pedals is to the left of the steering
wheel.
Press the switch to the left to move
the pedals closer to your body.
Press the switch to the right to move
the pedals away.
Before you start driving, fully press
the brake pedal to confirm the
adjustment is right for you.
The vehicle may have a memory
function, which lets pedal settings
be saved and recalled. SeeMemory
Seats 066.
Ignition Positions (Key
Access)
Vehicles with Key Access have an
ignition switch with four different
positions.
To shift out of P (Park), the ignition
must be in ON/RUN or ACC/
ACCESSORY and the regular brake
pedal must be applied.
0 (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) 0223.
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.
Page 219 of 427

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
218 Driving and Operating
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 0237.
{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.
1 (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.
2 (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.
3 (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.
Page 220 of 427

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Driving and Operating 219
Ignition Positions
(Keyless Access)
Vehicles with Keyless Access have
pushbutton starting.
Pressing the button cycles it through
three modes: ACC/ACCESSORY,
ON/RUN/START, and Stopping the
Engine/OFF.
The Remote Keyless Entry (RKE)
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 interferenceto the Keyless Access system. See
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0
34 orRemote Keyless Entry
(RKE) System Operation (Key
Access) 032.
To shift out of P (Park), the vehicle
must be in ACC/ACCESSORY or
ON/RUN and the brake pedal must
be applied.
Stopping the Engine/LOCK/
OFF (No Indicator Lights) : When
the vehicle is stopped, press
ENGINE START/STOP 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) 0223.
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 0167.
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.
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
Page 221 of 427

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
220 Driving and Operating
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 0237.
{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,
press and hold ENGINE START/
STOP for longer than two seconds,
or press twice in five seconds. ACC/ACCESSORY (Amber
Indicator Light) :
This mode allows
some electrical accessories to be
used when the engine is off.
With the ignition off, pressing the
button one time without the brake
pedal applied will place the ignition
system in ACC/ACCESSORY.
The ignition will switch from ACC/
ACCESSORY to OFF after
five minutes to prevent battery
rundown.
ON/RUN/START (Green Indicator
Light) : This mode is for driving and
starting. With the ignition off, and
the brake pedal applied, pressing
the button once will place the
ignition system in ON/RUN/START.
Once engine cranking begins,
release the button. Engine cranking
will continue until the engine starts.
See Starting the Engine 0220. The
ignition will then remain in ON/RUN.
Service Only Mode
This power mode is available for
service and diagnostics, and to
verify the proper operation of the
malfunction indicator lamp as may be required for emission inspection
purposes. With the vehicle off, and
the brake pedal not applied,
pressing and holding the button for
more than five seconds will place
the vehicle in Service Only Mode.
The instruments and audio systems
will operate as they do in ON/RUN,
but the vehicle will not be able to be
driven. The engine will not start in
Service Only Mode. Press the
button again to turn the vehicle off.
Starting the Engine
Move the shift lever to P (Park) or
N (Neutral). The engine will not start
in any other position. 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.
Page 222 of 427

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Driving and Operating 221
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.
SeeAdd-On Electrical
Equipment 0282.
Starting Procedure (Key
Access)
1. With your foot off the
accelerator pedal, turn the
ignition key to START. When
the engine starts, let go of the
key. The idle speed will go
down as the engine gets warm.
Do not race the engine
immediately after starting it.
Operate the engine and
transmission gently to allow the
oil to warm up and lubricate all
moving parts.
When the low fuel warning
lamp is on and the FUEL
LEVEL LOW message is
displayed in the Driver Information Center (DIC), hold
the ignition switch in the
START position to continue
engine cranking.
Caution
Cranking the engine for long
periods of time, by returning the
ignition to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down.
2. If the engine does not start after five to 10 seconds,
especially in very cold weather
(below −18 °C or 0 °F), it could
be flooded with too much
gasoline. Try pushing the
accelerator pedal all the way to
the floor and holding it there
while holding the key in START
for up to 15 seconds. Wait at
least 15 seconds between each
try, to allow the cranking motor
to cool down. When the engine starts, let go of the key and
accelerator. If the vehicle starts
briefly but then stops again, do
the same thing. This clears the
extra gasoline from the engine.
Do not race the engine
immediately after starting it.
Operate the engine and
transmission gently until the oil
warms up and lubricates all
moving parts.
Starting Procedure (Keyless
Access)
1. With the Keyless Access
system, the RKE transmitter
must be in the vehicle. Press
ENGINE START/STOP with the
brake pedal applied. When the
engine begins cranking, let go
of the button.
The idle speed will go down as
the engine gets warm. Do not
race the engine immediately
after starting it.
If the RKE transmitter is not in
the vehicle, if there is
interference, or if the RKE
battery is low, the Driver
Page 223 of 427

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
222 Driving and Operating
Information Center (DIC) will
display a message. SeeKey
and Lock Messages 0162.
Caution
Cranking the engine for long
periods of time, by returning the
ignition to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down.
2. If the engine does not start after five to 10 seconds,
especially in very cold weather
(below −18 °C or 0 °F), it could
be flooded with too much
gasoline. Try pushing the
accelerator pedal all the way to
the floor and holding it there as
you press ENGINE START/
STOP, for up to a maximum of
15 seconds. Wait at least
15 seconds between each try,
to allow the cranking motor to
cool down. When the engine starts, let go of the button, and
the accelerator. If the vehicle
starts briefly but then stops
again, do the same thing. This
clears the extra gasoline from
the engine. Do not race the
engine immediately after
starting it. Operate the engine
and transmission gently until
the oil warms up and lubricates
all moving parts.
Engine Heater
{Warning
Do not plug in the engine block
heater while the vehicle is in
parked in a garage or under a
carport. Property damage or
personal injury may result. Always
park the vehicle in a clear open
area away from buildings or
structures.
If equipped, the engine heater can
provide easier starting and better
fuel economy during engine
warm-up in cold weather conditions at or below
−18 °C (0 °F). Vehicles
with an engine heater should be
plugged in at least four hours before
starting. There may be an internal
thermostat in the plug end of the
cord, which will prevent engine
heater operation at temperatures
above −18 °C (0 °F).
To Use the Engine Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord. The cord is by
the left front fender, next to the
engine compartment fuse
block.
Check the heater cord for
damage. If it is damaged, do
not use it. See your dealer for
a replacement. Inspect the
cord for damage yearly.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
Page 224 of 427

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-9955936) - 2017 - crc - 7/5/16
Driving and Operating 223
{Warning
Improper use of the heater cord
or an extension cord can damage
the cord and may result in
overheating and fire.. Plug the cord into a
three-prong electrical utility
receptacle that is protected
by a ground fault detection
function. An ungrounded
outlet could cause an
electric shock.
. Use a weatherproof,
heavy-duty, 15 amp-rated
extension cord if needed.
Failure to use the
recommended extension
cord in good operating
condition, or using a
damaged heater or
extension cord, could make
(Continued)
Warning (Continued)
it overheat and cause a fire,
property damage, electric
shock, and injury.
. Do not operate the vehicle
with the heater cord
permanently attached to the
vehicle. Possible heater
cord and thermostat
damage could occur.
. While in use, do not let the
heater cord touch vehicle
parts or sharp edges. Never
close the hood on the
heater cord.
. Before starting the vehicle,
unplug the cord, reattach
the cover to the plug, and
securely fasten the cord.
Keep the cord away from
any moving parts.
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 Retained Accessory Power
(RAP) powered.
These features work with the
ignition on. Once the ignition is
turned off, the windows and sunroof
continue to work up to 10 minutes or
until any door is opened. The radio