2018 GMC YUKON XL brake light

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 227Shifting Into 4
m or AUTO
Turn the knob to the 4
m or AUTO
position. This can be done at any
speed. The indicator light will flash
while shifting. It will remain on when
the shift is completed.
Shifting Into 2
mTurn the knob to the 2
m position.
This can be done at any speed. The
indicator light will flash while
shifting. It will remain on when the
shift is completed. Brakes Antilock Brake
System (ABS) This vehicle has an Antilock Brake
System (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
may be heard while this test is going
on, and it may 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
0 145 . 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 vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
228 Driving and Operating 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
0 145 . CautionDriving with the parking brake on
can overheat the brake system
and cause premature wear or
damage to brake system parts.
Make sure that the parking brake
is fully released and the brake
warning light is off before driving.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the parking brake pedal.
If the parking brake is not released
when you begin to drive, a DIC
message will appear and a chime
will sound warning you that the
parking brake is still on.
Brake Assist The Brake Assist feature is
designed to assist the driver in
stopping or decreasing vehicle
speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 231CautionDo not repeatedly brake or
accelerate heavily when TCS is
off. The vehicle driveline could be
damaged.
To turn off only TCS, press and
release
g . The traction off light
idisplays in the instrument cluster.
The appropriate message will
display in the DIC. To turn TCS on
again, press and release
g . The
traction off light
i displayed in the
instrument cluster will turn off.
If TCS is limiting wheel spin when
gis pressed, the system will not turn
off until the wheels stop spinning.
To turn off both TCS and StabiliTrak,
press and hold
g until the traction
off light
i and the StabiliTrak OFF
light
g come on and stay on in the
instrument cluster, then release. The
appropriate message will display in
the DIC. To turn TCS and StabiliTrak on
again, press and release
g . The
traction off light
i and the
StabiliTrak OFF light
g in the
instrument cluster turn off.
StabiliTrak will automatically turn on
if the vehicle exceeds 56 km/h
(35 mph). Traction control will
remain off.
The vehicle has a Trailer Sway
Control (TSC) feature and a Hill
Start Assist (HSA) feature.
See Trailer Sway Control (TSC)
0 273 or Hill Start Assist (HSA)
0 229 .
Adding accessories can affect the
vehicle performance. See
Accessories and Modifications
0 278 .
Hill Descent
Control (HDC) If equipped, Hill Descent Control
(HDC) sets and maintains vehicle
speed while driving down steep grades in a forward or reverse gear.
The HDC switch is on the center
stack, below the climate controls.
Press
5 to enable or disable HDC.
Vehicle speed must be below
50 km/h (31 mph).
When enabled, the HDC light
displays on the instrument cluster.
A blinking HDC light indicates the
system is actively applying the
brakes to maintain vehicle speed.
HDC can maintain vehicle speeds
between 1 and 30 km/h (1 and
19 mph) on grades greater than or
equal to 10%.
If HDC is to be used for more than
three minutes or on grades steeper
than 25%, the transfer case should
be put into Four-Wheel Drive Low
(4
n ) to reduce the possibility of
brake overheating.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
232 Driving and Operating Noise from the hydraulic brake
control module is normal when HDC
is active.
When HDC is activated, the initial
HDC speed is set to the current
driving speed. It can be increased or
decreased by pressing +RES or
SET- on the steering wheel, or by
applying the accelerator or brake
pedal. This adjusted speed
becomes the new set speed.
HDC will remain enabled between
30 and 60 km/h (19 and 37 mph);
however, vehicle speed cannot be
set or maintained in this range. HDC
will automatically disable if the
vehicle speed is above 80 km/h
(50 mph) or above 60 km/h
(37 mph) for at least 30 seconds.
5 must be pressed again to
re-enable HDC. HDC may disable
after an extended period of use.
If this happens, HDC will require
time to cool down. The length of
time HDC remains active depends
on road conditions, grade, set
speed, vehicle loading, and outside
temperature. When enabled, if the vehicle speed
is above 30 km/h (19 mph) and
below 60 km/h (37 mph), a DIC
message will display.
Magnetic Ride Control This vehicle may have a semi-active
damping system called Magnetic
Ride Control. With this feature,
improved vehicle ride and handling
is provided under a variety of
passenger and loading conditions.
Magnetic Ride Control is fully
automatic and uses a computer
controller to continuously monitor
vehicle speed, wheel to body
position, lift/dive, and steering
position of the vehicle. The
controller then sends signals to
each shock absorber to
independently adjust the damping
level to provide the optimum
vehicle ride.
Magnetic Ride Control also interacts
with the Tow/Haul Mode that, when
activated, will provide additional
control of the shock absorbers. This
additional control results in better
ride and handling characteristics when the vehicle is loaded or towing
a trailer. See “ Tow/Haul Mode ”
under Towing Equipment 0 267 .
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 (ALC)
rear suspension is available on
light-duty vehicles and comes as a
part of the Magnetic Ride Control
suspension, if equipped. 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

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 235.
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 0 133 .
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 SET – will result in cruise
control set to the current vehicle
speed.
Using Cruise Control on Hills
How well the cruise control works
on hills depends on the vehicle
speed, the load, and the steepness
of the hills. When going up steep
hills, pressing the accelerator pedal may be necessary to maintain
vehicle speed. When going
downhill, Cruise Grade Braking
helps maintain the driver selected
speed.
Cruise Grade Braking is enabled
when the vehicle is started and
cruise control is active. It is not
enabled in Range Selection Mode.
It assists in maintaining driver
selected speed when driving on
downhill grades by using the engine
and transmission to slow the
vehicle.
To disable and enable Cruise Grade
Braking for the current ignition key
cycle, press and hold the Tow/Haul
button for five seconds. A DIC
message displays.
For other forms of Grade Braking,
see Automatic Transmission 0 216
and Tow/Haul Mode 0 222 .
Ending Cruise Control
There are four ways to end cruise
control:
.
Step lightly on the brake pedal.
.
Press
* . .
Shift the transmission to
N (Neutral).
.
To turn off cruise control,
press
5 .
Erasing Speed Memory
The cruise control set speed is
erased from memory if
5 is pressed
or if the ignition is turned off.
Adaptive Cruise Control If equipped with Adaptive Cruise
Control (ACC), it allows for selecting
the cruise control set speed and
following gap. Read this entire
section before using this system.
ACC uses a camera and radar
sensors to detect other vehicles.
See Radio Frequency Statement
0 396 . The following gap is the
following time (or distance) between
your vehicle and a vehicle detected
directly ahead in your path, moving
in the same direction. If no vehicle
is detected in your path, ACC works
like regular cruise control.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
Driving and Operating 239back your vehicle will follow a
vehicle detected ahead. Consider
traffic and weather conditions when
selecting the following gap. The
range of selectable gaps may not be
appropriate for all drivers and
driving conditions.
Changing the gap setting
automatically changes the alert
timing sensitivity (Far, Medium,
or Near) for the Forward Collision
Alert (FCA) feature. See Forward
Collision Alert (FCA) System 0 246 .
Alerting the Driver
Without Head-Up Display With Head-Up Display
If ACC is engaged, driver action
may be required when ACC cannot
apply sufficient braking because of
approaching a vehicle too rapidly.
When this condition occurs, six red
lights or the collision alert symbol on
the HUD, if equipped, will flash on
the windshield, and either eight
beeps will sound from the front,
or both sides of the Safety Alert
Seat will pulse five times. See
“ Collision/Detection Systems ” under
Vehicle Personalization 0 158 .
See Defensive Driving 0 190 . Approaching and Following a
Vehicle
The vehicle ahead indicator is in the
instrument cluster and HUD,
if equipped.
The vehicle ahead indicator only
displays when a vehicle is detected
in your vehicle ’ s path moving in the
same direction.
If this indicator is not displaying,
ACC will not respond to or brake to
vehicles ahead.
ACC automatically slows the vehicle
down and adjusts vehicle speed to
follow the vehicle in front at the
selected follow gap. The vehicle
speed increases or decreases to
follow the vehicle in front of you, but
will not exceed the set speed. It may
apply limited braking, if necessary.
When braking is active, the brake
lights will come on. The automatic

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
242 Driving and Operating 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
* .
.
Press
5 . Erasing Speed Memory
The cruise control set speed is
erased from memory if
5 is pressed
or if the ignition is turned off.
Cleaning the Sensing System
The radar sensor on the front of the
vehicle can become blocked by
snow, ice, dirt, or mud. This area
needs to be cleaned for ACC to
operate properly.
For cleaning instructions, see
“ Washing the Vehicle ” under
Exterior Care 0 360 .
System operation may also be
limited under snow, heavy rain,
or road spray conditions. Driver Assistance
Systems This vehicle may have features that
work together to help avoid crashes
or reduce crash damage while
driving, backing, and parking. Read
this entire section before using
these systems.
{ WarningDo not rely on the Driver
Assistance Systems. These
systems do not replace the need
for paying attention and driving
safely. You may not hear or feel
alerts or warnings provided by
these systems. Failure to use
proper care when driving may
result in injury, death, or vehicle
damage. See Defensive Driving
0 190 .
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
246 Driving and Operating parking assist on again, select On in
vehicle personalization. The On with
Towbar setting allows for the
parking assist to work properly with
an attached 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 ” and “ Collision/
Detection Systems ” under Vehicle
Personalization 0 158 .
Assistance Systems for
Driving If equipped, when driving the
vehicle in a forward gear, Forward
Collision Alert (FCA), Lane
Departure Warning (LDW), Lane
Keep Assist (LKA), Side Blind Zone
Alert (SBZA), Lane Change Alert
(LCA), and/or Forward Automatic
Braking (FAB) 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 8 km/h (5 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 0 235 .
{ Warning
FCA is a warning system and
does not apply the brakes. When
approaching a slower-moving or
(Continued) Warning (Continued) 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. It also may not
provide any warning at all. FCA
does not warn of pedestrians,
animals, signs, guardrails,
bridges, construction barrels,
or other objects. Be ready to take
action and apply the brakes. See
Defensive Driving 0 190 .
FCA can be disabled with either the
FCA steering wheel control or,
if equipped, through vehicle
personalization. See “ Collision/
Detection Systems ” under Vehicle
Personalization 0 158 .