ignition GMC YUKON XL 2018 Service Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Lighting 173If the headlamps are in the
automatic position or on low beam,
the high-beam headlamps will turn
on. Depending on the type of
headlamp, they will either turn off
after a short duration or stay on as
long as you hold the lever toward
you. The high-beam indicator on the
instrument cluster will come on.
Release the lever to return to
normal operation.
Daytime Running
Lamps (DRL) DRL can make it easier for others to
see the front of the vehicle during
the day. Fully functional DRL are
required on all vehicles first sold in
Canada.
The DRL system comes on when
the following conditions are met:
.
The ignition is on.
.
The exterior lamp control is
in AUTO.
.
The transmission is not in
P (Park). .
The light sensor determines it is
daytime.
When the DRL system is on, only
the DRL are on. The taillamps,
sidemarker lamps, instrument panel
lights, and other lamps will not
be on.
When it begins to get dark, the
automatic headlamp system
switches from DRL to the
headlamps.
To turn off the DRL, turn the exterior
lamp control to
O and then release.
For vehicles first sold in Canada, off
will only work when the vehicle is
parked.
Automatic Headlamp
System When the exterior lamp control is
set to AUTO and it is dark enough
outside, the headlamps come on
automatically. There is a light sensor on top of the
instrument panel. Do not cover the
sensor, otherwise the headlamps
will come on when they are not
needed.
The system may also turn on the
headlamps when driving through a
parking garage or tunnel.
If the vehicle is started in a dark
garage, the automatic headlamp
system comes on immediately. If it
is light outside when the vehicle
leaves the garage, there is a slight
delay before the automatic
headlamp system changes to the
DRL. During that delay, the
instrument cluster may not be as
bright as usual. Make sure the
instrument panel brightness control

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
174 Lighting is in the full bright position. See
Instrument Panel Illumination
Control 0 176 .
When it is bright enough outside,
the headlamps will turn off or may
change to Daytime Running
Lamps (DRL).
The automatic headlamp system
turns off when the exterior lamp
control is turned to
O or the ignition
is off.
Lights On with Wipers If the windshield wipers are
activated in daylight with the engine
on, and the exterior lamp control is
in AUTO, the headlamps, parking
lamps, and other exterior lamps
come on. The transition time for the
lamps coming on varies based on
wiper speed. When the wipers are
not operating, these lamps turn off.
Move the exterior lamp control to
Oor
; to disable this feature. Hazard Warning Flashers
| : Press this button to make the
front and rear turn signal lamps
flash on and off. Press again to turn
the flashers off.
When the hazard warning flashers
are on, the vehicle's turn signals will
not work. Turn and Lane-Change
Signals
An arrow on the instrument cluster
flashes in the direction of the turn or
lane change.
Move the turn signal lever all the
way up or down to signal a turn.
Raise or lower the lever for less
than one second until the arrow
starts to flash to signal a lane
change. This causes the turn
signals to automatically flash three
times. It will flash six times if Tow/
Haul Mode is active. Holding the
turn signal lever for more than
one second will cause the turn
signals to flash until the lever is
released.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Lighting 175The lever returns to its starting
position whenever it is released.
If after signaling a turn or a lane
change the arrows flash rapidly or
do not come on, a signal bulb could
be burned out.
Replace any burned out bulbs. If a
bulb is not burned out, check the
fuse. See Fuses and Circuit
Breakers 0 309 .
Turn Signal On Chime
If the turn signal is left on for more
than 1.2 km (0.75 mi), a chime
sounds at each flash of the turn
signal. The message TURN
SIGNAL ON will also appear in the
Driver Information Center (DIC). To
turn the chime and message off,
move the turn signal lever to the off
position. Fog Lamps
If equipped with fog lamps, the
button is on the exterior lamp
control, to the left of the steering
column.
The ignition must be on for the fog
lamps to come on.
# : Press to turn the fog lamps on
or off. A light will come on in the
instrument cluster.
When the fog lamps are turned on,
the parking lamps automatically
turn on. When the headlamps are changed
to high beam, the fog lamps also go
off. When the high-beam headlamps
are turned off, the fog lamps will
come on again.
Some localities have laws that
require the headlamps to be on with
the fog lamps.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
176 Lighting
Interior Lighting Instrument Panel
Illumination Control
This feature controls the brightness
of the instrument panel lights and is
next to the exterior lamp control.
D : Move the thumbwheel up or
down to brighten or dim the lights. Dome Lamps
There are dome lamps in the
overhead console and the headliner,
if equipped.
To change the dome lamp settings,
press the following:
OFF : Turns the lamps off, even
when a door is open.
DOOR : The lamps come on
automatically when a door is
opened.
ON : Turns all dome lamps on. Reading Lamps
There are reading lamps in the
overhead console and the headliner,
if equipped. To operate, the ignition
must be on or in ACC/ACCESSORY
or using Retained Accessory
Power (RAP).

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Lighting 177
Press
m or
n next to each reading
lamp to turn it on or off.
Lighting Features Entry Lighting Some exterior lamps and the interior
lamps turn on briefly at night, or in
areas with limited lighting, when
Kis pressed on the Remote Keyless
Entry (RKE) transmitter. When a
door is opened, the interior lamps
come on if the dome lamp control is
in the DOOR position. After about
30 seconds the exterior lamps turn
off. Entry lighting can be disabled
manually by changing the ignition
out of the OFF position, or by
pressing the RKE transmitter
Qbutton.
This feature can be changed. See
“ Vehicle Locator Lights ” under
Vehicle Personalization 0 158 .
Exit Lighting Some exterior lamps and interior
lamps come on at night, or in areas
with limited lighting, when the driver
door is opened after the ignition is
turned off. The exterior lamps and interior lamps remain on for a set
amount of time, then automatically
turn off.
The exterior lamps turn off
immediately by turning the exterior
lamp control off.
This feature can be changed. See
Vehicle Personalization 0 158 .
Battery Load
Management The vehicle has Electric Power
Management (EPM), which
estimates the battery's temperature
and state of charge. It then adjusts
the voltage for best performance
and extended life of the battery.
When the battery's state of charge
is low, the voltage is raised slightly
to quickly bring the charge back up.
When the state of charge is high,
the voltage is lowered slightly to
prevent overcharging. The voltmeter
gauge or the voltage display on the
Driver Information Center (DIC),
if equipped, may show the voltage

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
178 Lighting moving up or down. This is normal.
If there is a problem, an alert will be
displayed.
The battery can be discharged at
idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all the
power that is needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power, whenever
needed. It can temporarily reduce
the power demands of some
accessories. Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,
this action may be noticeable to the
driver. If so, a DIC message might
be displayed and it is recommended
that the driver reduce the electrical
loads as much as possible.
Battery Power Protection This feature shuts off the dome and
reading lamps if they are left on for
more than 10 minutes when the
ignition is off. This will keep the
battery from running down.
Exterior Lighting Battery
Saver The exterior lamps turn off about
10 minutes after the ignition is
turned off, if the parking lamps or
headlamps have been manually left
on. This protects against draining
the battery. To restart the 10-minute
timer, turn the exterior lamp control
to the
O position and then back to
the
; or
2 position. To keep the lamps on for more than
10 minutes, the ignition must be on
or in ACC/ACCESSORY.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
182 Climate Controls Changing the mode cancels the
automatic operation of the mode.
Press AUTO to return to automatic
operation.
Y : Air is directed to the instrument
panel outlets.
\ : Air is divided between the
instrument panel and floor outlets.
[ : Air is directed to the floor
outlets, with some to the windshield,
side window outlets, and second
row floor outlets.
- : This mode clears the windows
of fog or moisture. Air is directed to
the windshield, floor outlets, and
side window vents.
0 : Press to clear the windshield
of fog or frost more quickly. Air is
directed to the windshield and the
side window vents. The system
automatically forces outside air into
the vehicle and the air conditioning
compressor will run, unless the
outside temperature is close to
freezing.
Do not drive the vehicle until all
windows are clear.
See Air Vents 0 185 . A/C : Press to turn the air
conditioning system on or off. An
indicator light comes on to show
that the air conditioning is enabled.
If the fan is turned off, the air
conditioner will not run. The A/C
light will stay on even if the outside
temperatures are below freezing.
@ : Press to turn on recirculation.
An indicator light comes on. Air is
recirculated to quickly cool the
inside of the vehicle. It can also be
used to help reduce outside air and
odors that enter the vehicle. The air
conditioning compressor also comes
on when this mode is activated.
Auto Defog : The climate control
system uses a sensor to
automatically detect high humidity
inside the vehicle. When high
humidity is detected, the climate
control system may adjust to
outside air supply, turn on the air
conditioner, and direct more air to
the windshield. If the climate control
system does not detect possible
window fogging, it returns to normal
operation. To turn Auto Defog off or on, see “ Climate and Air Quality ”
under Vehicle Personalization
0 158 .
Rear Window Defogger The rear window defogger uses a
warming grid to remove fog from the
rear window.
K : Press to turn the rear window
defogger on or off. An indicator light
on the button comes on to show that
the rear window defogger is on.
The rear window defogger only
works when the ignition is in on. The
defogger turns off if the ignition is
turned off or to ACC/ACCESSORY.
The rear window defogger can be
set to automatic operation. When
Auto Rear Defog is selected, the
rear window defogger turns on
automatically when the vehicle is
first started in cold weather and
turns off when the vehicle is
warmed. To turn Auto Rear Defog
on or off, see “ Climate and Air
Quality ” under Vehicle
Personalization 0 158 .

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
188 Driving and Operating
Driving and
Operating Driving Information Distracted Driving . . . . . . . . . . . . 189
Defensive Driving . . . . . . . . . . . . . 190
Drunk Driving . . . . . . . . . . . . . . . . . 190
Control of a Vehicle . . . . . . . . . . . 190
Braking . . . . . . . . . . . . . . . . . . . . . . . 190
Steering . . . . . . . . . . . . . . . . . . . . . . 191
Off-Road Recovery . . . . . . . . . . . 191
Loss of Control . . . . . . . . . . . . . . . 192
Off-Road Driving . . . . . . . . . . . . . 192
Driving on Wet Roads . . . . . . . . 197
Hill and Mountain Roads . . . . . 198
Winter Driving . . . . . . . . . . . . . . . . 198
If the Vehicle Is Stuck . . . . . . . . 200
Vehicle Load Limits . . . . . . . . . . . 200
Starting and Operating New Vehicle Break-In . . . . . . . . . 204
Adjustable Throttle and Brake
Pedal . . . . . . . . . . . . . . . . . . . . . . . 205
Ignition Positions (Keyless
Access) . . . . . . . . . . . . . . . . . . . . . 205
Ignition Positions (Key
Access) . . . . . . . . . . . . . . . . . . . . . 207
Starting the Engine . . . . . . . . . . . 209
Engine Heater . . . . . . . . . . . . . . . . 210 Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . . 212
Shifting Into Park . . . . . . . . . . . . . 212
Shifting out of Park . . . . . . . . . . . 213
Parking over Things
That Burn . . . . . . . . . . . . . . . . . . . 214
Active Fuel Management . . . . . 214
Extended Parking . . . . . . . . . . . . 214
Engine Exhaust Engine Exhaust . . . . . . . . . . . . . . 215
Running the Vehicle While
Parked . . . . . . . . . . . . . . . . . . . . . . 215
Automatic Transmission Automatic Transmission . . . . . . 216
Manual Mode . . . . . . . . . . . . . . . . . 218
Tow/Haul Mode . . . . . . . . . . . . . . . 222
Drive Systems Four-Wheel Drive . . . . . . . . . . . . . 222
Brakes Antilock Brake
System (ABS) . . . . . . . . . . . . . . . 227
Parking Brake . . . . . . . . . . . . . . . . 228
Brake Assist . . . . . . . . . . . . . . . . . . 228
Hill Start Assist (HSA) . . . . . . . . 229
Ride Control Systems
Traction Control/Electronic
Stability Control . . . . . . . . . . . . . 229 Hill Descent Control (HDC) . . . 231
Magnetic Ride Control . . . . . . . . 232
Locking Rear Axle . . . . . . . . . . . . 232
Automatic Level Control . . . . . . 232
Cruise Control Cruise Control . . . . . . . . . . . . . . . . 233
Adaptive Cruise Control . . . . . . 235
Driver Assistance Systems Driver Assistance Systems . . . 242
Assistance Systems for
Parking or Backing . . . . . . . . . . 243
Assistance Systems for
Driving . . . . . . . . . . . . . . . . . . . . . . 246
Forward Collision Alert (FCA)
System . . . . . . . . . . . . . . . . . . . . . . 246
Forward Automatic
Braking (FAB) . . . . . . . . . . . . . . . 248
Side Blind Zone
Alert (SBZA) . . . . . . . . . . . . . . . . 250
Lane Change Alert (LCA) . . . . . 250
Lane Departure
Warning (LDW) . . . . . . . . . . . . . 252
Lane Keep Assist (LKA) . . . . . . 252
Fuel Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 254
California Fuel
Requirements . . . . . . . . . . . . . . . 255
Fuels in Foreign Countries . . . 255
Fuel Additives . . . . . . . . . . . . . . . . 255

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
196 Driving and Operating
{ WarningGetting out of the vehicle on the
downhill side when stopped
across an incline is dangerous.
If the vehicle rolls over, you could
be crushed or killed. Always get
out on the uphill side of the
vehicle and stay well clear of the
rollover path.
Driving in Mud, Sand, Snow,
or Ice Use a low gear when driving in
mud — the deeper the mud, the
lower the gear. Keep the vehicle
moving to avoid getting stuck.
Traction changes when driving on
sand. On loose sand, such as on
beaches or sand dunes, the tires
tend to sink into the sand. This
affects steering, accelerating, and
braking. Drive at a reduced speed
and avoid sharp turns or abrupt
maneuvers. Traction is reduced on hard packed
snow and ice and it is easy to lose
control. Reduce vehicle speed when
driving on hard packed snow
and ice.
{ WarningDriving on frozen lakes, ponds,
or rivers can be dangerous. Ice
conditions vary greatly and the
vehicle could fall through the ice;
you and your passengers could
drown. Drive your vehicle on safe
surfaces only.
Driving in Water
{ Warning
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream
and you and your passengers
could drown. If it is only shallow
water, it can still wash away the
ground from under your tires.
(Continued) Warning (Continued) Traction could be lost, and the
vehicle could roll over. Do not
drive through rushing water.
CautionDo not drive through standing
water if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe. Deep water can damage the
axle and other vehicle parts.
If the standing water is not too deep,
drive through it slowly. At faster
speeds, water can get into the
engine and cause it to stall. Stalling
can occur if the exhaust pipe is
under water. Do not turn off the
ignition when driving through water.
If the exhaust pipe is under water,
the engine will not start. When going
through water, the brakes get wet
and it may take longer to stop. See
“ Driving on Wet Roads ” later in this
section.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/21/17
198 Driving and Operating
Hill and Mountain Roads Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips 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.
{ WarningUsing 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. { WarningCoasting downhill in N (Neutral)
or with the ignition off is
dangerous. This can cause
overheating of the brakes and
loss of steering assist. Always
have the engine running and the
vehicle in gear.
.
Drive at speeds that keep the
vehicle in its own lane. Do not
swing wide or cross the
center line.
.
Be alert on top of hills;
something could be in your lane
(e.g., stalled car, accident).
.
Pay attention to special road
signs (e.g., falling rocks area,
winding roads, long grades,
passing or no-passing zones)
and take appropriate action. Winter Driving Driving on Snow or Ice Snow or ice between the tires and
the road creates less traction or
grip, so drive carefully. Wet ice can
occur at about 0 °C (32 °F) when
freezing rain begins to fall. Avoid
driving on wet ice or in freezing rain
until roads can be treated.
For Slippery Road Driving:
.
Accelerate gently. Accelerating
too quickly causes the wheels to
spin and makes the surface
under the tires slick.
.
Turn on Traction Control. See
Traction Control/Electronic
Stability Control 0 229 .
.
The Antilock Brake System
(ABS) improves vehicle stability
during hard stops, but the
brakes should be applied sooner
than when on dry pavement.
See Antilock Brake System
(ABS) 0 227 .