brakes GMC YUKON DENALI 2015 User Guide

Black plate (11,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-11
Warning (Continued)
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 on
page 10-41.
.Turn off cruise control.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{Warning
Using the brakes to slow the
vehicle on a long downhill slope
can cause brake overheating, can
reduce brake performance, and
could result in a loss of braking.
Shift the transmission to a lower
gear to let the engine assist the
brakes on a steep downhill slope.
{Warning
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. This can cause
overheating of the brakes and
(Continued)

Black plate (12,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-12 Driving and Operating
Warning (Continued)
loss of steering. Always have the
engine running and the vehicle
in gear.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in your
own lane.
.Be alert on top of hills;
something could be in your lane
(stalled car, accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow
or ice between the tires and the
road, creating less traction or grip.Wet ice can occur at about 0°C
(32°F) when freezing rain begins to
fall, resulting in even less traction.
Avoid driving on wet ice or in
freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently so
traction is not lost. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick, so there is even less
traction.
Traction Control should be turned
on. See
Traction Control/Electronic
Stability Control on page 9-41.
The Antilock Brake System (ABS)
improves vehicle stability during
hard stops on slippery roads, but
apply the brakes sooner than when
on dry pavement. See Antilock
Brake System (ABS) on page 9-38.
Allow greater following distance on
any slippery road 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 on slippery
surfaces.
Blizzard Conditions
Being stuck in snow can be a
serious situation. Stay with the
vehicle unless there is help nearby.
If possible, use Roadside
Assistance. See
Roadside
Assistance Program on page 13-5.
To get help and keep everyone in
the vehicle safe:
.Turn on the hazard warning
flashers.
.Tie a red cloth to an outside
mirror.

Black plate (21,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-21
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).
SeeTransmission Messages on
page 5-47. 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
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 9-39.{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 the ENGINE START/
STOP button 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.

Black plate (31,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-31
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 9-32.
{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

Black plate (33,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-33
In vehicles with gasoline engines, when the shift lever is moved from
D (Drive) to M (Manual Mode), a downshift may occur. The gear that the
transmission is operating in when the shift lever is moved from D (Drive) to
M (Manual Mode) determines if a downshift occurs. See the following chart.Gear before
shifting from D
(Drive) to M
(Manual Mode) 8th 7th 6th 5th 4th 3rd 2nd 1st
Range after
shifting from
D (Drive) to
M (Manual Mode)
– Tow/Haul not
engaged M6 M6 M5 M4 M3 M3 M2 M1
Range after
shifting from
D (Drive) to
M (Manual Mode)
– Tow/Haul
engaged M6 M5 M4 M3 M3 M3 M2 M1
Grade Braking is not available when
Range Selection Mode is active.
See Tow/Haul Mode on page 9-34. 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.

Black plate (38,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-38 Driving and Operating
4. Shift the transmission toN (Neutral).
5. Shift the transfer case to 2
m.
6. Turn the transfer case knob clockwise to N (Neutral) until it
stops and hold it there until the
N (Neutral) light starts blinking.
This will take at least
10 seconds. Then slowly release
the dial to the 4
nposition. The
N (Neutral) light will come on
when the transfer case shift to
N (Neutral) is complete.
7. With the engine running, verify that the transfer case is in
N (Neutral) by shifting the
transmission to R (Reverse),
then shift the transmission to
D (Drive). There should be no
movement of the vehicle while
shifting the transmission.
8. Turn the engine off, and the ignition to ACC/ACCESSORY. 9. Place the transmission shift
lever in P (Park). See
Recreational Vehicle Towing on
page 10-77.
10. Turn the ignition to LOCK/OFF.
Shifting Out of N (Neutral)
To shift:
1. Set the parking brake and apply the brake pedal.
2. Turn the ignition to ON/RUN with the engine off.
3. Shift the transmission to N (Neutral).
4. Turn the transfer case knob to the desired setting.
After the transfer case has
shifted out of N (Neutral), the
N (Neutral) light will go out.
5. Release the parking brake.
6. Start the engine and shift the transmission to the desired gear.
Brakes
Antilock Brake
System (ABS)
This vehicle has ABS, an advanced
electronic braking system that helps
prevent a braking skid.
When the vehicle begins to drive
away, ABS checks itself.
A momentary motor or clicking noise
might be heard while this test is
going on, and it might even be
noticed that the brake pedal moves
a little. This is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
on page 5-24.

Black plate (39,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-39
If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses the wheels are
slowing down. If one of the wheels
is about to stop rolling, the computer
will separately work the brakes at
each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
you steer around the obstacle while
braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehiclesuddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You may hear the ABS
pump or motor operating and feel
the brake pedal pulsate. This is
normal.
Braking in Emergencies
ABS allows you to steer and brake
at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Parking Brake
Set the parking brake by holding the
regular brake pedal down, then
pushing down the parking brake
pedal.
If the ignition is on, the brake
system warning light will come on.
See
Brake System Warning Light on
page 5-23.

Black plate (41,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-41
activated. During the transition
period between when the driver
releases the brake pedal and starts
to accelerate to drive off on a grade,
HSA holds the braking pressure for
a maximum of two seconds to
ensure that there is no rolling. The
brakes will automatically release
when the accelerator pedal is
applied within the two-second
window. If the vehicle is equipped
with the Integrated Trailer Brake
Control (ITBC) system, HSA may
also apply the trailer brakes. It will
not activate if the vehicle is in a
drive gear and facing downhill or if
the vehicle is facing uphill and in
R (Reverse). There may be
situations on minor hills (less than
5% grade) with a loaded vehicle or
while pulling a trailer where HSA
may activate.Ride Control Systems
Traction Control/
Electronic Stability
Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak®, an
electronic stability control system.
These systems help limit wheel spin
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any
of the drive wheels are spinning or
beginning to lose traction. When this
happens, TCS applies the brakes to
the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling. StabiliTrak selectively applies
braking pressure to any one of the
vehicle wheel brakes to assist the
driver in keeping the vehicle on the
intended path. Trailer Sway Control
(TSC) is also on automatically when
the vehicle is started. See
Trailer
Sway Control (TSC) on page 9-84.
If cruise control is being used and
traction control or StabiliTrak begins
to limit wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road
conditions allow.
Both systems come on
automatically when the vehicle is
started and begins to move. The
systems may be heard or felt while
they are operating or while
performing diagnostic checks. This
is normal and does not mean there
is a problem with the vehicle.

Black plate (44,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-44 Driving and Operating
Locking Rear Axle
Vehicles with a locking rear axle can
give more traction on snow, mud,
ice, sand, or gravel. It works like a
standard axle most of the time, but
when traction is low, this feature will
allow the rear wheel with the most
traction to move the vehicle.
Automatic Level Control
The automatic level control rear
suspension is available on light-duty
vehicles and comes as a part of the
MagneRide suspension, if equipped.
Automatic Level Control (ALC) may
also be available as a stand alone
feature.This type of level control is fully
automatic and will provide a better
leveled riding position as well as
better handling under a variety of
passenger and loading conditions.
An air compressor connected to the
rear shocks will raise or lower the
rear of the vehicle to maintain
proper vehicle height. The system is
activated when the ignition key is
turned to ON/RUN and will
automatically adjust vehicle height
thereafter. The system may exhaust
(lower vehicle height) for up to
10 minutes after the ignition key has
been turned off. You may hear the
air compressor operating when the
height is being adjusted.
If a weight-distributing hitch is being
used, it is recommended to allow
the shocks to inflate, thereby
leveling the vehicle prior to adjusting
the hitch.
Cruise Control
{Warning
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. Do not use
cruise control on winding roads or
in heavy traffic.
Cruise control can be dangerous
on slippery roads. On such roads,
fast changes in tire traction can
cause excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.
With cruise control a speed of about
40 km/h (25 mph) or more can be
maintained without keeping your
foot on the accelerator. Cruise
control does not work at speeds
below about 40 km/h (25 mph).
If the brakes are applied, the cruise
control disengages.

Black plate (46,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-46 Driving and Operating
The cruise control indicator on the
instrument cluster turns green after
cruise control has been set to the
desired speed. SeeInstrument
Cluster on page 5-11.
Resuming a Set Speed
If the cruise control is set at a
desired speed and then the brakes
or
*is applied, the cruise control is
disengaged without erasing the set
speed from memory.
Once the vehicle speed reaches
about 40 km/h (25 mph) or more,
briefly press +RES. The vehicle
returns to the previous set speed.
Increasing Speed While Using
Cruise Control
If the cruise control system is
already activated:
.Press and hold the +RES button
until the vehicle accelerates to
the desired speed, then
release it.
.To increase vehicle speed in
small increments, briefly press
+RES. For each press, the
vehicle goes about 1.6 km/h
(1 mph) faster.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster on
page 5-11. The increment value
used depends on the units
displayed.
Reducing Speed While Using
Cruise Control
If the cruise control system is
already activated:
.Press and hold the SET– button
until the desired lower speed is
reached, then release it.
.To slow down in small
increments, briefly press SET–.
For each press, the vehicle goes
about 1.6 km/h (1 mph) slower. The speedometer reading can be
displayed in either English or metric
units. See
Instrument Cluster on
page 5-11. The increment value
used depends on the units
displayed.
Passing Another Vehicle While
Using Cruise Control
Use the accelerator pedal to
increase the vehicle speed. When
you take your foot off the pedal, the
vehicle will slow down to the
previous set cruise speed. While
pressing the accelerator pedal or
shortly following the release to
override cruise control, briefly
pressing the SET– button will result
in cruise control set to the current
vehicle speed.