brake GMC YUKON DENALI 2015 Repair Manual

Black plate (58,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-58 Driving and Operating
parking assist to work properly with
a small item attached to the trailer
hitch. Turn off parking assist when
towing a trailer.
To turn the rear parking assist
symbols, guidance lines, or Rear
Cross Traffic Alert on or off, see
“Rear Camera”underVehicle
Personalization on page 5-50
Assistance Systems for
Driving
If equipped, when driving the
vehicle forward, Forward Collision
Alert (FCA), Lane Departure
Warning (LDW), Side Blind Zone
Alert (SBZA), Lane Change Alert
(LCA), and/or the Active Emergency
Braking System can help to avoid a
crash or reduce crash damage.
Forward Collision Alert
(FCA) System
If equipped, the FCA system may
help to avoid or reduce the harm
caused by front-end crashes. When approaching a vehicle ahead too
quickly, FCA provides a red flashing
alert on the windshield and rapidly
beeps or pulses the driver seat.
FCA also lights an amber visual
alert if following another vehicle
much too closely.
FCA detects vehicles within a
distance of approximately 60 m
(197 ft) and operates at speeds
above 40 km/h (25 mph). If the
vehicle has Adaptive Cruise Control
(ACC), it can detect vehicles to
distances of approximately 110 m
(360 ft) and operates at all speeds.
See
Adaptive Cruise Control on
page 9-47.
{Warning
FCA is a warning system and
does not apply the brakes. When
approaching a slower-moving or
stopped vehicle ahead too rapidly,
or when following a vehicle too
closely, FCA may not provide a
(Continued)
Warning (Continued)
warning with enough time to help
avoid a crash. FCA does not warn
of pedestrians, animals, signs,
guardrails, bridges, construction
barrels, or other objects. Be ready
to take action and apply the
brakes. For more information, see
Defensive Driving on page 9-3.
FCA can be disabled with the FCA
steering wheel control, or if your
vehicle is equipped with Adaptive
Cruise Control (ACC), through
vehicle personalization. See the
“Auto Collision Preparation” portion
of “Collision/Detection Systems”
under Vehicle Personalization on
page 5-50.

Black plate (59,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-59
Detecting the Vehicle Ahead
FCA warnings will not occur unless
the FCA system detects a vehicle
ahead. When the vehicle is
detected, the vehicle-ahead
indicator will display green. Vehicles
may not be detected on curves,
highway exit ramps, or hills; or due
to poor visibility. FCA will not detect
another vehicle ahead until it is
completely in the driving lane.
{Warning
FCA does not provide a warning
to help avoid a crash, unless it
detects a vehicle. FCA may not
detect a vehicle ahead if the FCA
sensor is blocked by dirt, snow,
or ice, or if the windshield is
damaged. It may also not detect a
vehicle on winding or hilly roads,
or in conditions that can limit
visibility such as fog, rain,
or snow, or if the headlamps or
windshield are not cleaned or in
proper condition. Keep the
windshield, headlamps, and FCA
sensors clean and in good repair.Collision Alert
With HUD
Without HUD
When your vehicle approaches
another detected vehicle too rapidly,
the red FCA display will flash on the
windshield. Also, eight rapid
high-pitched beeps will sound from
the front, or both sides of the Safety
Alert Seat will pulse five times.
When this Collision Alert occurs, the
brake system may prepare for driver
braking to occur more rapidly which
can cause a brief, mild deceleration.
Continue to apply the brake pedal

Black plate (60,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-60 Driving and Operating
as needed. Cruise control may be
disengaged when the Collision Alert
occurs.
Tailgating Alert
The vehicle-ahead indicator will
display amber when you are
following a vehicle ahead much too
closely.
Selecting the Alert Timing
The Collision Alert control is on the
steering wheel. Press
[/3to
set the FCA timing to Far, Medium,
Near, or on some vehicles, Off. The
first button press shows the current
setting on the DIC. Additional button
presses will change this setting. The
chosen setting will remain until it is
changed and will affect the timing of
both the Collision Alert and the
Tailgating Alert features. The timing of both alerts will vary based on
vehicle speed. The faster the
vehicle speed, the farther away the
alert will occur. Consider traffic and
weather conditions when selecting
the alert timing. The range of
selectable alert timing may not be
appropriate for all drivers and
driving conditions.
If your vehicle is equipped with
Adaptive Cruise Control (ACC),
changing the FCA timing setting
automatically changes the ACC
following gap setting (Far, Medium,
or Near).
Unnecessary Alerts
FCA may provide unnecessary
alerts for turning vehicles, vehicles
in other lanes, objects that are not
vehicles, or shadows. These alerts
are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to
operate properly, cleaning the
outside of the windshield in front of
the camera sensor behind the
rearview mirror, and cleaning the
front of the vehicle where radar
sensors are located, may correct
the issue.
For cleaning instructions, see
“Washing the Vehicle”
under
Exterior Care on page 10-81.
System operation may also be
limited under snow, heavy rain,
or road spray conditions.
Active Emergency
Braking System
If the vehicle has Adaptive Cruise
Control (ACC) it also has the Active
Emergency Braking System, which
includes Intelligent Brake
Assist (IBA) and the Automatic
Collision Preparation (ACP) System.
These systems can provide a boost
to braking or automatically brake the
vehicle to help avoid or lessen the
severity of crashes when driving in a
forward gear.

Black plate (61,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-61
Intelligent Brake Assist (IBA)
IBA may activate when the brake
pedal is applied quickly by providing
a boost to braking based on the
speed of approach and distance to
a vehicle ahead.
Minor brake pedal pulsations or
pedal movement during this time is
normal and the brake pedal should
continue to be applied as needed.
IBA will automatically disengage
only when the brake pedal is
released.
{Warning
IBA may increase vehicle braking
in situations when it may not be
necessary. You could block the
flow of traffic. If this occurs, take
your foot off the brake pedal and
then apply the brakes as needed.
Automatic Collision
Preparation (ACP) System
When driving in a forward gear
above 9 km/h (5 mph), ACP may
help reduce crash damage by
applying the brakes. It has a
detection range of approximately
60 m (197 ft). This front automatic
braking can only occur if a vehicle is
detected. This is shown by the FCA
vehicle ahead indicator being lit.
SeeForward Collision Alert (FCA)
System on page 9-58.
{Warning
ACP is an emergency crash
preparation feature and is not
designed to avoid crashes. Do
not rely on ACP to brake the
vehicle.
ACP may not:
.Respond to stopped vehicles,
pedestrians, or animals.
(Continued)
Warning (Continued)
.Detect a vehicle ahead on
winding or hilly roads.
.Detect a stopped or
slow-moving vehicle or other
object ahead.
.Detect a vehicle when
weather limits visibility, such
as in fog, rain, or snow. In
these situations, ACP sensor
performance is limited.
Complete attention is always
required while driving, and you
should be ready to take action
and apply the brakes and/or steer
the vehicle to avoid crashes.
Brake Preparation
When quickly approaching a vehicle
ahead, Brake Preparation reduces
brake response time by having the
brake system prepared for driver
braking to occur more rapidly.

Black plate (62,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-62 Driving and Operating
Automatic Braking
If ACP detects it is about to crash
with the vehicle you are following
that is moving or has come to a
stop, and the brakes have not been
applied, it may automatically brake
hard. This can help to reduce crash
damage and it may even help to
avoid some very low speed crashes.
Automatic Braking may slow the
vehicle to a complete stop to try to
avoid a potential crash. The vehicle
will only hold at a stop briefly. A firm
press of the accelerator pedal will
also release Automatic Braking.
{Warning
Automatic Braking may
automatically brake the vehicle
suddenly in situations where it is
unexpected and undesired.
It could respond to a turning
vehicle ahead, guardrails, signs,
and other non-moving objects. To(Continued)
Warning (Continued)
override Automatic Braking, firmly
press the accelerator pedal, if it is
safe to do so.
Automatic Braking can be disabled
or reduced through vehicle
personalization. See the “Auto
Collision Preparation” portion of
“Collision/Detection Systems” under
Vehicle Personalization on
page 5-50.
{Warning
Using the Automatic Collision
Preparation System while towing
a trailer could cause you to lose
control of the vehicle and crash.
Turn the system off when towing
a trailer.
Side Blind Zone
Alert (SBZA)
If equipped, the SBZA system is a
lane-changing aid that assists
drivers with avoiding crashes that
occur with vehicles in the side blind
zone (or spot) areas. When the
vehicle is moving forward, the left or
right side mirror display will light up
if a vehicle is detected in that blind
zone. If the turn signal is activated
and a vehicle is also detected on
the same side, the display will flash
as an extra warning not to change
lanes. Since this system is part of
the Lane Change Alert system, read
the entire Lane Change Alert
section before using this feature.
Lane Change Alert (LCA)
If equipped, the Lane Change Alert
(LCA) system is a lane-changing aid
that assists drivers with avoiding
lane change crashes that occur with
vehicles in the side blind zone (or
spot) areas or with vehicles rapidly
approaching these areas from

Black plate (71,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-71
{Warning
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
When towing a trailer:
.Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
.Fully open the air outlets on
or under the instrument
panel.
.Also adjust the climate
control system to a setting
that brings in only outside air.
See“Climate Control
Systems” in the Index.
For more information about
Carbon Monoxide, see Engine
Exhaust on page 9-28. Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
Passing
More passing distance is needed
when towing a trailer. The
combination will not accelerate as
quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
{Caution
Making very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.
(Continued)

Black plate (72,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-72 Driving and Operating
Caution (Continued)
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a lower
gear before starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well. Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
When towing, use the Tow/Haul
Mode to prevent damage to the
engine or transmission. See
Tow/
Haul Mode on page 9-34.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine
off. If the overheat warning comes
on, see Engine Overheating on
page 10-16.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load.

Black plate (73,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-73
4. Reapply the brake pedal. Thenapply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11-3. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
Do not tow a trailer during break-in.
See
New Vehicle Break-In on
page 9-19.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too
heavy, the brakes may not work
well —or even at all. The driver
and passengers could be
seriously injured. The vehicle may
also be damaged; the resulting
repairs would not be covered by
(Continued)
Warning (Continued)
the vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer for advice and information
about towing a trailer with the
vehicle.
{Caution
Pulling a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.

Black plate (78,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
9-78 Driving and Operating
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue of
the trailer to help prevent the tongue
from contacting the road if it
becomes separated from the hitch.
Instructions about safety chains
may be provided by the hitch
manufacturer or by the trailer
manufacturer. If the trailer being
towed weighs up to 2 271 kg
(5,000 lb) with a factory-installed
step bumper, safety chains may be
attached to the attaching points on
the bumper, otherwise, safety
chains should be attached to holes
on the trailer hitch platform. Always
leave just enough slack so the
combination can turn. Never allow
safety chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 900 kg (2,000 lb) needs to have
its own brake system that is
adequate for the weight of the
trailer. Be sure to read and followthe instructions for the trailer brakes
so they are installed, adjusted, and
maintained properly.
Since the vehicle is equipped with
StabiliTrak, the trailer brakes cannot
tap into the vehicle's hydraulic
system.
Trailer Wiring Harness
The seven-pin trailer connector is
mounted in the bumper. This
connector can be plugged into a
seven-pin universal heavy-duty
trailer connector available through
your dealer.
The seven-wire harness contains
the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Green/Violet: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red/Green: Battery Feed
.Dark Blue: Trailer BrakeIf charging a remote (non-vehicle)
battery, press the Tow/Haul mode
button at the end of the shift lever.
This will boost the vehicle system
voltage and properly charge the
battery. If the trailer is too light for
Tow/Haul mode, turn on the
headlamps as a second way to
boost the vehicle system and
charge the battery.
Electric Brake Control Wiring
Provisions
These wiring provisions are
included with the vehicle as part of
the trailer wiring package. These
provisions are for an electric brake
controller.
The harness should be installed by
your dealer or a qualified service
center.

Black plate (79,1)GMC 2015i Yukon Denali/Yukon XL Denali Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-8431504) - 2015 - CRC - 7/30/14
Driving and Operating 9-79
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
Tow/Haul Mode.
This indicator light on the instrument
cluster comes on when the Tow/
Haul Mode is on.Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. See
Tow/Haul
Mode on page 9-34.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 percent of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” under
Trailer Towing on page 9-73. Tow/
Haul is most useful under the
following driving conditions:
.When pulling a heavy trailer or a
large or heavy load through
rolling terrain.
.When pulling a heavy trailer or a
large or heavy load in
stop-and-go traffic.
.When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired. Operating the vehicle in Tow/Haul
when lightly loaded or with no trailer
at all will not cause damage.
However, there is no benefit to the
selection of Tow/Haul when the
vehicle is unloaded. Such a
selection when unloaded may result
in unpleasant engine and
transmission driving characteristics
and reduced fuel economy. Tow/
Haul is recommended only when
pulling a heavy trailer or a large or
heavy load.
Integrated Trailer Brake
Control System
The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for use with electric trailer brakes or
most electric-over-hydraulic trailer
brakes.