warning GMC SIERRA DENALI 2018 Owners Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
266 Driving and Operating When parked on a hill, especially
when the vehicle has a heavy load,
you might notice an increase in the
effort to shift out of P (Park). See
“ Torque Lock ” under Shifting Into
Park 0 262
{ WarningIt is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running. If you have left
the engine running, the vehicle
can move suddenly. You or others
could be injured. To be sure the
vehicle will not move, even when
you are on fairly level ground,
always set the parking brake and
move the shift lever to P (Park).
See Shifting Into Park 0 262 and
Driving Characteristics and
Towing Tips 0 303 . { WarningIf equipped with four-wheel drive,
the vehicle will be free to roll if the
transfer case is in N (Neutral),
even when the shift lever is in
P (Park). You or someone else
could be seriously injured. Be
sure the transfer case is in a drive
gear — 2
m , 4
m , or 4
n or set the
parking brake before placing the
transfer case in N (Neutral). See
Shifting Into Park 0 262 .
R : Use this gear to back up.
Caution
Shifting to R (Reverse) while the
vehicle is moving forward could
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Shift to
R (Reverse) only after the vehicle
is stopped. To rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission, see If
the Vehicle Is Stuck 0 247 .
N : In this position, the engine does
not connect with the wheels. To
restart the engine when the vehicle
is already moving, use
N (Neutral) only.
Also, use N (Neutral) when the
vehicle is being towed.
{ WarningShifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift
into a drive gear while the engine
is running at high speed.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
272 Driving and Operating On vehicles with a diesel engine,
Tow/Haul Mode Grade Braking can
be enabled or disabled by pressing
the Tow/Haul Mode button. Use the
exhaust brake and Tow/Haul Mode
for maximum grade braking.
See Towing Equipment 0 325 .
For other forms of grade braking,
see Automatic Transmission 0 265
and Cruise Control 0 285 .
Drive Systems Four-Wheel Drive If equipped, four-wheel drive
engages the front axle for extra
traction.
Read the appropriate section for
transfer case operation before
using.
CautionDo not drive on clean, dry
pavement in 4
m and 4
n (if
equipped) for an extended period
of time. These conditions may
cause premature wear on the
vehicle ’ s powertrain.
Driving on clean, dry pavement in
4
m or 4
n may:
.
Cause a vibration to be felt in
the steering system.
.
Cause tires to wear faster.
.
Make the transfer case harder to
shift, and cause it to run noisier. { WarningIf equipped with four-wheel drive,
the vehicle will be free to roll if the
transfer case is in N (Neutral),
even when the shift lever is in
P (Park). You or someone else
could be seriously injured. Be
sure the transfer case is in a drive
gear — 2
m , 4
m , or 4
n or set the
parking brake before placing the
transfer case in N (Neutral). See
Shifting Into Park 0 262 .
Caution
Extended high-speed operation in
4
n may damage or shorten the
life of the drivetrain.
Engagement noise and bump when
shifting between 4
n and 4
m or from
N (Neutral), with the engine running,
is normal.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
280 Driving and Operating Shifting Out of N (Neutral)
To shift out of N (Neutral):
1. Set the parking brake and
apply the brake pedal.
2. Turn the ignition on with the
engine off.
3. Shift the transmission to
N (Neutral).
4. Turn the transfer case knob to
the desired setting.
After the transfer case has
shifted out of N (Neutral), the
N (Neutral) light will go out.
5. Release the parking brake.
6. Start the engine and shift the
transmission to the
desired gear. 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
0 152 . 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 Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 281Using 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
0 152 .
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
control module to supplement the
power brake system under
conditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle. The
stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time is
normal and the driver should
continue to apply the brake pedal as
the driving situation dictates. The
Brake Assist feature will
automatically disengage when the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 285Noise 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.
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. Cruise Control With cruise control a speed of about
40 km/h (25 mph) or more can be
maintained without keeping your
foot on the accelerator. Cruise
control does not work at speeds
below about 40 km/h (25 mph).
{ WarningCruise control can be dangerous
where you cannot drive safely at
a steady speed. Do not use
cruise control on winding roads or
in heavy traffic.
Cruise control can be dangerous
on slippery roads. On such roads,
fast changes in tire traction can
cause excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
288 Driving and Operating 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.
.
Vehicles with a diesel engine
have Cruise Grade Braking
enabled when Tow/Haul Mode is
on, the exhaust brake is on,
or both are on.
For other forms of descent control,
see Hill Descent Control (HDC)
0 284 , Automatic Transmission
0 265 , and Tow/Haul Mode 0 271 . 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 the ignition is turned off. 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
0 236 .
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 289Warning (Continued)Under many conditions, these
systems will not:
.
Detect children,
pedestrians, bicyclists,
or animals.
.
Detect vehicles or objects
outside the area monitored
by the system.
.
Work at all driving speeds.
.
Warn you or provide you
with enough time to avoid a
crash.
.
Work under poor visibility or
bad weather conditions.
.
Work if the detection sensor
is not cleaned or is covered
by ice, snow, mud, or dirt.
.
Work if the detection sensor
is covered up, such as with
a sticker, magnet, or metal
plate.
(Continued) Warning (Continued) .
Work if the area surrounding
the detection sensor is
damaged or not properly
repaired.
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.
Audible or Safety Alert Seat
Some driver assistance features
alert the driver of obstacles by
beeping. To change the volume of
the warning chime, see “ Comfort
and Convenience ” under Vehicle
Personalization 0 165 .
If equipped with the Safety Alert
Seat, the driver seat cushion may
provide a vibrating pulse alert
instead of beeping. To change this,
see “ Collision/Detection Systems ”
under Vehicle Personalization
0 165 . Assistance Systems for
Parking or Backing If equipped, the Rear Vision Camera
(RVC), Rear Parking Assist (RPA),
and Front Parking Assist (FPA) may
help the driver park or avoid objects.
Always check around the vehicle
when parking or backing.
The RVC and RPA will not work
properly if the tailgate is down. If the
tailgate is down, do not use these
systems.
Rear Vision Camera (RVC)
When the vehicle is shifted into
R (Reverse), the RVC displays an
image of the area behind the vehicle
in the infotainment display. The
previous screen displays when the
vehicle is shifted out of R (Reverse)
after a short delay. To return to the
previous screen sooner, press any
button on the infotainment system,
shift into P (Park), or reach a vehicle
speed of approximately
12 km/h (8 mph).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
290 Driving and Operating
1. View Displayed by the
Camera
1. View Displayed by the
Camera
2. Corners of the Rear Bumper Displayed images may be farther or
closer than they appear. The area
displayed is limited and objects that
are close to either corner of the
bumper or under the bumper do not
display.
A warning triangle may display on
the infotainment display to show
that RPA has detected an object.
This triangle changes from amber to
red and increases in size the closer
the object.
{ WarningThe camera(s) do not display
children, pedestrians, bicyclists,
crossing traffic, animals, or any
other object outside of the
cameras ’ field of view, below the
bumper, or under the vehicle.
Shown distances may be different
from actual distances. Do not
drive or park the vehicle using
only these camera(s). Always
check behind and around the
(Continued) Warning (Continued) vehicle before driving. Failure to
use proper care may result in
injury, death, or vehicle damage.
Parking Assist
With RPA, and if equipped with FPA,
as the vehicle moves at speeds of
less than 8 km/h (5 mph) the
sensors on the bumpers may detect
objects up to 2.5 m (8 ft) behind and
1.2 m (4 ft) in front of the vehicle
within a zone 25 cm (10 in) high off
the ground and below bumper level.
These detection distances may be
shorter during warmer or humid
weather. Blocked sensors will not
detect objects and can also cause
false detections. Keep the sensors
clean of mud, dirt, snow, ice, and
slush; and clean sensors after a car
wash in freezing temperatures.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 291
{ WarningThe Parking Assist system does
not detect children, pedestrians,
bicyclists, animals, or objects
located below the bumper or that
are too close or too far from the
vehicle. It is not available at
speeds greater than 8 km/h
(5 mph). To prevent injury, death,
or vehicle damage, even with
Parking Assist, always check the
area around the vehicle and
check all mirrors before moving
forward or backing. The instrument cluster may have a
parking assist display with bars that
show “ distance to object ” and object
location information for the Parking
Assist system. As the object gets
closer, more bars light up and the
bars change color from yellow to
amber to red.
When an object is first detected in
the rear, one beep will be heard
from the rear, or both sides of the
Safety Alert Seat will pulse two
times. When an object is very close
(<0.6 m (2 ft) in the vehicle rear,
or <0.3 m (1 ft) in the vehicle front),
a continuous beep will sound from
the front or rear, or both sides of the Safety Alert Seat will pulse five
times. Beeps for FPA are higher
pitched than for RPA.
Turning the Features On or Off Press
X on the center stack to
turn the Front and Rear Parking
Assist on or off. The indicator light in
the button comes on when the
features are on and turns off when
the features have been disabled.
Front and Rear Parking Assist can
be turned off, on, or on with towbar
through vehicle personalization. See
“ Park Assist ” under Vehicle
Personalization 0 165 . If the parking
assist is turned off through vehicle
personalization, the parking assist
button on the center stack will be
disabled. To turn the 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
292 Driving and Operating To turn the rear parking assist
symbols or guidance lines on or off,
see “ Rear Camera ” under Vehicle
Personalization 0 165 .
Assistance Systems for
Driving If equipped, when driving the
vehicle in a forward gear, Forward
Collision Alert (FCA), Lane
Departure Warning (LDW), and/or
Lane Keep Assist (LKA) 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).
{ WarningFCA 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. 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 0 236 .
FCA can be disabled with either the
FCA steering wheel control or,
if equipped, through vehicle
personalization. See “ Collision/
Detection Systems ” under Vehicle
Personalization 0 165 . Detecting the Vehicle Ahead
FCA warnings will not occur unless
the FCA system detects a vehicle
ahead. When a vehicle is detected,
the vehicle ahead indicator will
display green. Vehicles may not be
detected on curves, highway exit
ramps, or hills, due to poor visibility;
or if a vehicle ahead is partially
blocked by pedestrians or other
objects. 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,
(Continued)