2015 GMC YUKON brake light

Black plate (57,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
Driving and Operating 9-57
ACC may detect a vehicle that is
not in your lane and apply the
brakes.
ACC may occasionally provide an
alert and/or braking that is
considered unnecessary. It could
respond to vehicles in different
lanes, signs, guardrails, and other
stationary objects when entering or
exiting a curve. This is normal
operation. The vehicle does not
need service.Other Vehicle Lane Changes
ACC will not detect a vehicle ahead
until it is completely in the lane. The
brakes may need to be manually
applied.
Do Not Use ACC on Hills and
When Towing a Trailer
Do not use ACC when driving on
steep hills or when towing a trailer.
ACC will not detect a vehicle in the
lane while driving on steep hills. The
driver will often need to take over
acceleration and braking on steep
hills, especially when towing a
trailer. If the brakes are applied, the
ACC disengages.
Disengaging ACC
There are three ways to
disengage ACC:
.Step lightly on the brake pedal.
.Press*.
.Press5.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
5is pressed
or if the ignition is turned off.

Black plate (62,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
9-62 Driving and Operating
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 speedsabove 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 9-51.
{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
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 5-43.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.

Black plate (65,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
Driving and Operating 9-65
Warning (Continued)
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.
Automatic Braking
In some imminent front-end crash
situations, if the driver has not
applied the brakes, Automatic
Braking applies the brakes to help
reduce crash damage. It may even
help 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 in
situations where it may be
unnecessary. It could respond to
a turning vehicle ahead,
guardrails, signs, and other
non-moving objects. This could
be uncomfortable and startling. To
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 5-43.
{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

Black plate (82,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
9-82 Driving and Operating
Weight-Distributing Hitch
Adjustment
1. Body to Ground Distance
2. Front of Vehicle
When using a weight-distributing
hitch, the spring bars should be
adjusted so the distance (1) is the
same after coupling the trailer to the
tow vehicle and adjusting the hitch.
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue ofthe 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 follow
the 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 Brake
If charging a remote (non-vehicle)
battery, press the Tow/Haul mode
button at the end of the shift lever.

Black plate (83,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
Driving and Operating 9-83
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.
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 9-35.
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 9-78. 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.

Black plate (84,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
9-84 Driving and Operating
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.This symbol is on the Trailer Brake
Control Panel on vehicles with an
Integrated Trailer Brake Control
system. The power output to the
trailer brakes is based on the
amount of brake pressure being
applied by the vehicle’s brake
system, and on the type of trailer
brakes detected. This available
power output to the trailer brakes
can be adjusted to a wide range of
trailering situations.
The ITBC system is integrated with
the vehicle’
s brake, antilock brake,
and StabiliTrak systems. In trailering
conditions that cause the vehicle’s
antilock brake or StabiliTrak
systems to activate, power sent to
the trailer's brakes will be
automatically adjusted to minimize
trailer wheel lock-up. This does not
imply that the trailer has StabiliTrak.
If the vehicle’s brake, antilock brake,
or StabiliTrak systems are not
functioning properly, the ITBC
system may not be fully functional
or may not function at all. Make sure all of these systems are fully
operational to ensure full
functionality of the ITBC system.
The ITBC system is powered
through the vehicle's electrical
system. Turning the ignition off will
also turn off the ITBC system. The
ITBC system is fully functional only
when the ignition is in ON/RUN.
{Warning
Connecting a trailer that has an
air brake system may result in
reduced or complete loss of trailer
braking. There may be an
increase in stopping distance or
trailer instability which could
result in personal injury or
damage to the vehicle, trailer,
or other property. Use the ITBC
system only with electric or
electric over hydraulic trailer
brakes.

Black plate (88,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - CRC - 6/5/14
9-88 Driving and Operating
continues over multiple ignition
cycles, there is a problem with the
ITBC system. Have the vehicle
serviced.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message displays
while driving, the ITBC system may
not be fully functional or may not
function at all. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service.
A GM dealer may be able to
diagnose and repair problems with
the trailer. However, any diagnosis
and repair of the trailer is not
covered under the vehicle warranty.
Contact your trailer dealer for
assistance with trailer repairs and
trailer warranty information.Trailer Sway
Control (TSC)
Vehicles with StabiliTrak have a
TSC feature. Trailer sway is
unintended side-to-side motion of a
trailer while being towed. If the
vehicle is towing a trailer and the
TSC detects that sway is increasing,
the vehicle brakes are selectively
applied at each wheel, to help
reduce excessive trailer sway. If the
vehicle is equipped with the
Integrated Trailer Brake Control
(ITBC) system, and the trailer has
the electric actuated brake system,
StabiliTrak may also apply the trailer
brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak
warning light will flash on the
instrument cluster. Vehicle speed
must be reduced. If trailer sway
continues, StabiliTrak can reduce
engine torque to help slow the
vehicle. SeeTraction Control/
Electronic Stability Control on
page 9-44.
{Warning
Even if the vehicle is equipped
with TSC, trailer sway could result
in loss of control and the vehicle
could crash. If excessive trailer
sway is detected, slow down to a
safe speed. Check the trailer and
vehicle to help correct possible
causes. These could include an
improperly or overloaded trailer,
unrestrained cargo, improper
trailer hitch configuration,
excessive vehicle-trailer speed,
or improperly inflated or incorrect
vehicle or trailer tires. See Towing
Equipment on page 9-81 for
trailer ratings and hitch setup
recommendations.
Adding non-dealer accessories can
affect the vehicle performance. See
Accessories and Modifications on
page 10-3.

Black plate (1,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-7063682) - 2015 - crc - 6/5/14
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-3
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-5
Engine Oil . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil Life System . . . . . . 10-9
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-10
Engine Air Cleaner/Filter . . . . 10-13
Cooling System . . . . . . . . . . . . 10-14
Engine Coolant . . . . . . . . . . . . . 10-15
Engine Overheating . . . . . . . . 10-18
Engine Fan . . . . . . . . . . . . . . . . . 10-19
Washer Fluid . . . . . . . . . . . . . . . 10-20
Brakes . . . . . . . . . . . . . . . . . . . . . 10-20 Brake Fluid . . . . . . . . . . . . . . . . . 10-21
Battery . . . . . . . . . . . . . . . . . . . . . 10-23
Four-Wheel Drive . . . . . . . . . . . 10-24
Front Axle . . . . . . . . . . . . . . . . . . 10-24
Rear Axle . . . . . . . . . . . . . . . . . . 10-25
Noise Control System . . . . . . 10-26
Starter Switch Check . . . . . . . 10-27
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-27
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-27
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-28
Wiper Blade Replacement . . . . . . . . . . . . . . 10-28
Glass Replacement . . . . . . . . 10-29
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-29
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-30
Halogen Bulbs . . . . . . . . . . . . . . 10-30
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . 10-30
LED Lighting . . . . . . . . . . . . . . . 10-30
Headlamps . . . . . . . . . . . . . . . . . 10-30
Front Turn Signal Lamps . . . 10-31 Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-31
License Plate Lamp . . . . . . . . 10-32
Replacement Bulbs . . . . . . . . . 10-33
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-33
Fuses . . . . . . . . . . . . . . . . . . . . . . 10-34
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-34
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . 10-38
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . 10-40
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . 10-43
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-44
All-Season Tires . . . . . . . . . . . . 10-45
Winter Tires . . . . . . . . . . . . . . . . 10-45
Low-Profile Tires . . . . . . . . . . . 10-46
All-Terrain Tires . . . . . . . . . . . . 10-46
Tire Sidewall Labeling . . . . . . 10-46
Tire Designations . . . . . . . . . . . 10-48
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-49