2018 GMC YUKON brake

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Driving and Operating 253
.Clean the headlamps.
For cleaning instructions, see
“Washing the Vehicle” under
Exterior Care 0365.
System operation may also be
limited under snow, heavy rain,
or road spray conditions.
Forward Automatic
Braking (FAB)
If the vehicle has Forward Collision
Alert (FCA), it also has FAB, which
includes Intelligent Brake
Assist (IBA). When the system
detects a vehicle ahead in your path
that is traveling in the same
direction that you may be about to
crash into, it can provide a boost to
braking or automatically brake the
vehicle. This can help avoid or
lessen the severity of crashes when
driving in a forward gear. Depending
on the situation, the vehicle may
automatically brake moderately or
hard. This forward automatic
braking can only occur if a vehicle is
detected. This is shown by the FCA vehicle ahead indicator being lit.
See
Forward Collision Alert (FCA)
System 0250.
The system works when driving in a
forward gear between 8 km/h
(5 mph) and 80 km/h (50 mph),
or on vehicles with Adaptive Cruise
Control (ACC), above 4 km/h
(2 mph). It can detect vehicles up to
approximately 60 m (197 ft).{Warning
FAB is an emergency crash
preparation feature and is not
designed to avoid crashes. Do
not rely on FAB to brake the
vehicle. FAB will not brake
outside of its operating speed
range and only responds to
detected vehicles.
FAB may not: . Detect a vehicle ahead on
winding or hilly roads.
(Continued)
Warning (Continued)
.Detect all vehicles,
especially vehicles with a
trailer, tractors, muddy
vehicles, etc.
. Detect a vehicle when
weather limits visibility, such
as in fog, rain, or snow.
. Detect a vehicle ahead if it
is partially blocked by
pedestrians or other objects.
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.
FAB 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 FAB.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
254 Driving and Operating
{Warning
FAB 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 override FAB, firmly
press the accelerator pedal, if it is
safe to do so.
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.
FAB and IBA can be disabled
through vehicle personalization. See
“Collision/Detection Systems” under
Vehicle Personalization 0162.
{Warning
Using FAB or IBA while towing a
trailer could cause you to lose
control of the vehicle and crash.
Turn the system to Alert, or if the
vehicle has ACC to Off, when
towing a trailer.
A system unavailable message may
display if:
. The front of the vehicle or
windshield is not clean. .
Heavy rain or snow is interfering
with object detection.
. There is a problem with the
StabiliTrak system.
The FAB system does not need
service.
Side Blind Zone
Alert (SBZA)
If equipped, the SBZA system is a
lane-changing aid that assists
drivers with avoiding crashes that
occur with moving vehicles in the
side blind zone (or spot) areas.
When the vehicle is in a forward
gear, the left or right side mirror
display will light up if a moving
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 (LCA)
system, read the entire LCA section
before using this feature.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
264 Driving and Operating
.The trailer must be equipped
with brakes adequate for the
intended use. A loaded trailer
weighing more than 900 kg
(2,000 lb) must be equipped with
its own brake system, with
brakes working on all axles.
Trailer braking equipment
conforming to Canadian
Standards Association (CSA)
requirement CAN3-D313, or its
equivalent, is recommended.
. Do not tow a trailer during the
first 800 km (500 mi) to prevent
damage to the engine, axle,
or other parts.
. Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
. 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.
. Do not use Adaptive Cruise
Control when towing. .
Turn off Parking Assist and Rear
Cross Traffic Alert (RTCA) when
towing.
. The Forward Automatic Braking
System should be set to Off
when towing. See Forward
Automatic Braking (FAB) 022.
. Turn off Lane Keep Assist (LKA)
when towing. See Lane Keep
Assist (LKA) 0257.
{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.
(Continued)
Warning (Continued)
.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 0219.
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.
The structure, tires, and brakes of
the trailer must be rated to carry the
load. Inadequate trailer equipment
can cause the combination to
operate in an unexpected or unsafe
manner.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Driving and Operating 265
tires, and mirrors. Get familiar with
the handling and braking of the rig.
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 TurnsCaution
Making very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.
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 0225.
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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
266 Driving and Operating
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, seeEngine Overheating 0298.
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.
4. Reapply the brake pedal. Then apply 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 0376.
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 0209.
Before towing a trailer, see
"Hands-Free Operation" under
Liftgate 045.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Driving and Operating 267
{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
or the trailer brakes are
inadequate for the load, the
vehicle may not stop as expected.
The driver and passengers could
be seriously injured. The vehicle
may also be damaged; the
resulting repairs would not be
covered by 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.
To identify the trailering capacity of
the vehicle, read the information in
“Weight of the Trailer” following.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of your passengers. So please read
this section carefully before pulling a
trailer.
Weight of the Trailer
Safe trailering requires monitoring
the weight, speed, altitude, road
grades, outside temperature, and
how frequently the vehicle is used to
pull a trailer. Take into consideration
any special equipment on the
vehicle, and the amount of tongue
weight the vehicle can carry. See
“Weight of the Trailer Tongue”
later
in this section for more information.
Trailer Weight Rating (TWR) is
calculated assuming the tow vehicle
has only the driver and all required
trailering equipment. Weight of
additional optional equipment,
passengers, and cargo in the tow
vehicle must be subtracted from the
trailer weight rating.
Use the following chart to determine
how much the trailer can weigh,
based upon the vehicle model and
options.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
272 Driving and Operating
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) must be
equipped with its own brake system,
with brakes working on all axles.
Trailer braking equipment
conforming to Canadian Standards
Association (CSA) requirement
CAN3-D313, or its equivalent, is
recommended.
State and local regulations may also
require the trailer to have its own
braking system if loaded above a
certain threshold. These
requirements vary from state to
state.
Be sure to read and follow the
instructions for the trailer brakes so
they are installed, adjusted, and
maintained properly. These
requirements vary from state to
state.Do not tap into the vehicle's
hydraulic brake system.
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.
Use only a round, seven-wire
connector with flat blade terminals
meeting SAE J2863 specifications
for proper electrical connectivity.
The seven-wire harness contains
the following trailer circuits:
.
Yellow/Grey: Left Stop/Turn
Signal
. Green/Violet: Right Stop/Turn
Signal
. Grey/Brown: Taillamps
. White: Ground .
White/Green: Back-up Lamps
. Red/Green: Battery Feed
. Dark Blue: Trailer Brake
To help charge a remote
(non-vehicle) battery, press the Tow/
Haul Mode button at the end of the
shift lever. If the trailer is too light for
Tow/Haul Mode, turn on the
headlamps to help 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Driving and Operating 273
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 0225.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 % of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” under
Trailer Towing 0266. 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.
This symbol is on the Trailer Brake
Control Panel on vehicles with an
ITBC system. The power output to
the trailer brakes is based on the
amount of brake pressure being
applied by the vehicle’s brake