2018 GMC YUKON XL light

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 197After Off-Road Driving Remove any brush or debris that
has collected on the underbody or
chassis, or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the body structure, driveline,
steering, suspension, wheels, tires,
and exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
More frequent maintenance service
is required. See the Maintenance
Schedule 0 370 .
Driving on Wet Roads Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep-standing or flowing water. { WarningWet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under the vehicle's
tires so they actually ride on the
water. This can happen if the road is wet enough and you are going fast
enough. When the vehicle is
hydroplaning, it has little or no
contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips Besides slowing down, other wet
weather driving tips include:
.
Allow extra following distance.
.
Pass with caution.
.
Keep windshield wiping
equipment in good shape.
.
Keep the windshield washer fluid
reservoir filled.
.
Have good tires with proper
tread depth. See Tires 0 320 .
.
Turn off cruise control.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 199.
Allow greater following distance
and watch for slippery spots. Icy
patches can occur on otherwise
clear roads in shaded areas.
The surface of a curve or an
overpass can remain icy when
the surrounding roads are clear.
Avoid sudden steering
maneuvers and braking while
on ice.
.
Turn off cruise control.
Blizzard Conditions Stop the vehicle in a safe place and
signal for help. Stay with the vehicle
unless there is help nearby.
If possible, use Roadside
Assistance. See Roadside
Assistance Program 0 390 . To get
help and keep everyone in the
vehicle safe:
.
Turn on the hazard warning
flashers.
.
Tie a red cloth to an outside
mirror. { WarningSnow can trap engine exhaust
under the vehicle. This may
cause exhaust gases to get
inside. Engine exhaust contains
carbon monoxide (CO), which
cannot be seen or smelled. It can
cause unconsciousness and even
death.
If the vehicle is stuck in snow:
.
Clear snow from the base of
the vehicle, especially any
blocking the exhaust pipe.
.
Open a window about 5 cm
(2 in) on the vehicle side
that is away from the wind,
to bring in fresh air.
.
Fully open the air outlets on
or under the instrument
panel.
.
Adjust the climate control
system to circulate the air
inside the vehicle and set
(Continued) Warning (Continued) the fan speed to the highest
setting. See “ Climate
Control Systems. ”
For more information about CO,
see Engine Exhaust 0 215 .
To save fuel, run the engine for
short periods to warm the vehicle
and then shut the engine off and
partially close the window. Moving
about to keep warm also helps.
If it takes time for help to arrive,
when running the engine, push the
accelerator pedal slightly so the
engine runs faster than the idle
speed. This keeps the battery
charged to restart the vehicle and to
signal for help with the headlamps.
Do this as little as possible, to
save fuel.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
200 Driving and Operating
If the Vehicle Is Stuck Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
If stuck too severely for the traction
system to free the vehicle, turn the
traction system off and use the
rocking method. See Traction
Control/Electronic Stability Control
0 229 .
{ WarningIf the vehicle's tires spin at high
speed, they can explode, and you
or others could be injured. The
vehicle can overheat, causing an
engine compartment fire or other
damage. Spin the wheels as little
as possible and avoid going
above 56 km/h (35 mph).
Rocking the Vehicle to Get
it Out
Turn the steering wheel left and
right to clear the area around the
front wheels. Turn off any traction
system. Shift back and forth between R (Reverse) and a low
forward gear, spinning the wheels
as little as possible. To prevent
transmission wear, wait until the
wheels stop spinning before shifting
gears. Release the accelerator
pedal while shifting, and press
lightly on the accelerator pedal
when the transmission is in gear.
Slowly spinning the wheels in the
forward and reverse directions
causes a rocking motion that could
free the vehicle. If that does not get
the vehicle out after a few tries, it
might need to be towed out. If the
vehicle does need to be towed out,
see Towing the Vehicle 0 355 .
Vehicle Load Limits It is very important to know how
much weight the vehicle can
carry. This weight is called the
vehicle capacity weight and
includes the weight of all
occupants, cargo, and all
nonfactory-installed options.
Two labels on the vehicle may
show how much weight it was designed to carry, the Tire and
Loading Information label and
the Certification/Tire label.
{ Warning
Do not load the vehicle any
heavier than the Gross
Vehicle Weight Rating
(GVWR), or either the
maximum front or rear Gross
Axle Weight Rating (GAWR).
This can cause systems to
break and change the way the
vehicle handles. This could
cause loss of control and a
crash. Overloading can also
reduce stopping distance,
damage the tires, and shorten
the life of the vehicle.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
206 Driving and Operating To shift out of P (Park), the ignition
must be on or in ACC/
ACCESSORY, 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) 0 212 .
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).
When the vehicle is shifted into
P (Park), the ignition system will
turn 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 ignition is turned
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 off. On vehicles with an automatic transmission, the
shift lever must be in P (Park)
to turn the ignition off.
4. Set the parking brake. See
Parking Brake 0 228 .
{ WarningTurning 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 207The 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 turn the ignition
on. Once engine cranking begins,
release the button. Engine cranking
will continue until the engine starts.
See Starting the Engine 0 209 .
Service 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 Mode. The
instruments and audio systems will
operate as they do when the ignition
is on, but the vehicle will not be able to be driven. The engine will not
start in Service Mode. Press the
button again to turn the ignition off.
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 on or in 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) 0 212 .
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
208 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 0 228 .
{ 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.
CautionUsing 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
222 Driving and Operating
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.
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. See Tow/Haul Mode Light 0 146 and
Hill and Mountain Roads 0 198 .
Also see “ Tow/Haul Mode ” under
Towing Equipment 0 267 .
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 0 218 .
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.
To disable or enable Tow/Haul
Grade Braking within the current
ignition 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 Towing Equipment 0 267 .
For other forms of grade braking,
see Automatic Transmission 0 216
and Cruise Control 0 233 .Drive Systems Four-Wheel Drive If equipped, four-wheel drive
engages the front axle for extra
traction.
CautionDo not drive on clean, dry
pavement in 4
m and 4
n (if
equipped) for an extended period
of time. These conditions may
cause premature wear on the
vehicle ’ s powertrain.
Driving on clean, dry pavement in 4
m or 4
n 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 223
{ WarningShifting the transfer case to
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or someone else
could be seriously injured. Be
sure to set the parking brake
before placing the transfer case in
N (Neutral). See Parking Brake
0 228 .
CautionExtended high-speed operation in
4
n may damage or shorten the
life of the drivetrain.
Engagement noise and bump when
shifting between 4
n and 4
m or from
N (Neutral), with the engine running,
is normal.
Shifting into 4
n will turn Traction
Control and StabiliTrak off. See
Traction Control/Electronic Stability
Control 0 229 . Two Speed Automatic
Transfer Case
If equipped, use the transfer case
knob next to the steering wheel to
shift into and out of four-wheel drive.
All of the lights will blink on then off
momentarily when the ignition
turned on. The light that remains on
will indicate the state of the
transfer case.
If the indicator mark on the switch
does not match up with the light
then that likely means the switch
was moved when the ignition
was off. The indicator mark on the switch
must line up with the indicator light
before a shift can be commanded.
To command a shift rotate the
transfer case switch to the new
desired position. The light will blink
meaning that the shift is in progress.
When the shift is completed the new
position will be illuminated. If the
transfer case cannot complete a
shift command, it will go back to its
last chosen setting.
The settings are:
N (Neutral) : Use only when the
vehicle needs to be towed.
See Recreational Vehicle Towing
0 355 or Towing the Vehicle 0 355 .
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