GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
198 Driving and Operating
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 0235.
. 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) 0232.
. Allow greater following distance
and watch for slippery spots. Icy
patches can occur on otherwise
clear roads in shaded areas.
The surface of a curve or an
overpass can remain icy when
the surrounding roads are clear.
Avoid sudden steering
maneuvers and braking while
on ice. .
Turn off cruise control.
Blizzard Conditions
Stop the vehicle in a safe place and
signal for help. Stay with the vehicle
unless there is help nearby.
If possible, use Roadside
Assistance. See Roadside
Assistance Program 0466. To get
help and keep everyone in the
vehicle safe:
. Turn on the hazard warning
flashers.
. Tie a red cloth to an outside
mirror.
{Warning
Snow can trap engine exhaust
under the vehicle. This may
cause exhaust gases to get
inside. Engine exhaust contains
carbon monoxide (CO), which
cannot be seen or smelled. It can
cause unconsciousness and even
death.
(Continued)
Warning (Continued)
If the vehicle is stuck in snow:
. Clear snow from the base of
the vehicle, especially any
blocking the exhaust pipe.
. Open a window about 5 cm
(2 in) on the vehicle side
that is away from the wind,
to bring in fresh air.
. Fully open the air outlets on
or under the instrument
panel.
. Adjust the climate control
system to circulate the air
inside the vehicle and set
the fan speed to the highest
setting. See “Climate
Control Systems.”
For more information about CO,
see Engine Exhaust 0220.
To save fuel, run the engine for
short periods to warm the vehicle
and then shut the engine off and
partially close the window. Moving
about to keep warm also helps.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 213
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.
Starting Procedure
1. For Key Access vehicles, turnthe ignition key to Start. When
the engine starts, let go of the
key. For Keyless Access
vehicles, the RKE transmitter
must be in the vehicle. Press
ENGINE START/STOP with the
brake pedal applied. When the
engine begins cranking, let go
of the button.
The driver may observe a
minor, and temporary, brake
pedal kickback when starting
the vehicle. This is normal.
The idle speed will go down as
the engine gets warm. Do not
race the engine immediately
after starting it. Operate the engine and transmission gently
to allow the oil to warm up and
lubricate all moving parts.
When the low fuel warning light
is on and the FUEL LEVEL
LOW message is displayed in
the Driver Information Center
(DIC), hold the ignition switch
in the START position to
continue engine cranking.Caution
Cranking the engine for long
periods of time, by returning the
ignition to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down.
2. If the engine does not start after five to 10 seconds,
especially in very cold weather
(below −18 °C or 0 °F), it could
be flooded with too much
gasoline. Try pushing the accelerator pedal all the way to
the floor and holding it there
while holding the key in START
or ENGINE START/STOP for
up to a maximum of
15 seconds. Wait at least
15 seconds between each try,
to allow the cranking motor to
cool down. When the engine
starts, let go of the key or
button and accelerator. If the
vehicle starts briefly but then
stops again, do the same thing.
This clears the extra gasoline
from the engine. Do not race
the engine immediately after
starting it. Operate the engine
and transmission gently until
the oil warms up and lubricates
all moving parts.
Stop/Start System
If equipped, the Stop/Start system
will shut off the engine to help
conserve fuel. It has components
designed for the increased number
of starts.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 221
Automatic
Transmission
If equipped, there is an electronic
shift lever position indicator within
the instrument cluster. This display
comes on when the ignition is in
ACC/ACCESSORY, on or
service mode.
There are several different positions
for the shift lever.
SeeDriver Mode Control 0238 and
“Range Selection Mode” under
Manual Mode 0224.
P : This position locks the rear
wheels. Use P (Park) when starting
the engine because the vehicle
cannot move easily. 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”
underShifting Into
Park 0217.
{Warning
It 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 0217 and
Driving Characteristics and
Towing Tips 0287.
{Warning
If 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, 4m, or 4n—or set the
parking brake before placing the
transfer case in N (Neutral). See
Four-Wheel Drive 0227.
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.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 235
pedal pulsation, and/or pedal
movement during this time may
occur. Continue to apply the brake
pedal as the driving situation
dictates. Brake Assist disengages
when the brake pedal is released.
Hill Start Assist (HSA)
{Warning
Do not rely on the HSA feature.
HSA does not replace the need to
pay attention and drive safely.
You may not hear or feel alerts or
warnings provided by this system.
Failure to use proper care when
driving may result in injury, death,
or vehicle damage. See
Defensive Driving0187. When the vehicle is stopped on a
grade, Hill Start Assist (HSA)
prevents the vehicle from rolling in
an unintended direction during the
transition from brake pedal release
to accelerator pedal apply. The
brakes release when the accelerator
pedal is applied. If the accelerator
pedal is not applied within a few
minutes, the Electric Parking Brake
will apply. The brakes may also
release under other conditions. Do
not rely on HSA to hold the vehicle.
HSA is available when the vehicle is
facing uphill in a forward gear,
or when facing downhill in
R (Reverse). The vehicle must
come to a complete stop on a grade
for HSA to activate.
Ride Control Systems
Traction Control/
Electronic Stability
Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak/
Electronic Stability Control (ESC)
system. These systems help limit
wheel spin and assist the driver in
maintaining control, especially on
slippery road conditions.
TCS activates if it senses any of the
drive wheels are spinning or
beginning to lose traction. When this
happens, TCS applies the brakes to
the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak/ESC activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak/ESC selectively applies
braking pressure to any one of the
vehicle wheel brakes to assist the
driver in keeping the vehicle on the
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 239
Vehicles with the MODE graphic on
the knob will have a menu selection
screen in the instrument cluster to
select the desired mode. When the
Drive Mode knob is turned to the
right, the mode list will display and
activate the next available mode.If equipped, select Terrain Mode by
pressing the
gbelow the 4m
transfer case button.
Modes:
Normal Mode :Use for normal city
and highway driving to provide a
smooth, soft ride. This mode
provides a balanced setting
between comfort and handling. This
is the standard mode and when
selected, there is no indicator in the
instrument cluster.
8Sport Mode : Use where road
conditions or personal preference
demand a more controlled
response. When you enter this mode you will
immediately feel a down shift. In this
mode, the vehicle also monitors
driving behaviors and automatically
enables Performance Shift Features
when spirited driving is detected.
These features maintain lower
transmission gears to increase
available engine braking and
improve acceleration response. The
vehicle will exit these features and
return to normal operation after a
short period when no spirited driving
is detected. The steering will
change to provide more precise
control. If the vehicle has Magnetic
Ride Control, the suspension will
change to provide better cornering
performance.
When selected, the Sport Mode light
displays in the instrument cluster.
7Off-Road Mode :
Use to
improve driving at moderate speeds,
on grass, gravel, dirt, unpaved
roads, or snow-covered roads that
have not been groomed or plowed.
The accelerator pedal will be more
sensitive to provide finer control of
the torque at the wheels.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 245
It assists in maintaining driver
selected speed when driving on
downhill grades by using the engine
and transmission to slow the
vehicle.
For other forms of descent control,
seeHill Descent Control (HDC)
0 237, Automatic Transmission
0 221, and Tow/Haul Mode 0227.
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
5is pressed
or the ignition is turned off.
Adaptive Cruise Control
(1500 Series)
If equipped, Adaptive Cruise Control
(ACC) allows the cruise control set
speed and following gap to be
selected. Read this entire section
before using this system. The
following gap is the following time
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. ACC uses a windshield
mounted front camera sensor.
If a vehicle is detected in your path,
ACC can apply acceleration or
limited, moderate braking to
maintain the selected following gap.
To disengage ACC, apply the brake.
If ACC is controlling the vehicle
speed when the Traction Control
System (TCS) or StabiliTrak/
Electronic Stability Control (ESC)
system activates, ACC may
automatically disengage. See
Traction Control/Electronic Stability
Control 0235. When road
conditions allow ACC to be safely used, ACC can be turned back on.
Disabling the TCS or StabiliTrak/
ESC system will disengage and
prevent engagement of ACC.
ACC can reduce the need for you to
frequently brake and accelerate,
especially when used on
expressways, freeways, and
interstate highways. When used on
other roads, you may need to take
over the control of braking or
acceleration more often.
{Warning
ACC has limited braking ability
and may not have time to slow
the vehicle down enough to avoid
a collision with another vehicle
you are following. This can occur
when vehicles suddenly slow or
stop ahead, or enter your lane.
Also see
“Alerting the Driver” later
in this section. Complete attention
is always required while driving
and you should be ready to take
action and apply the brakes. See
Defensive Driving 0187.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 249
.Pressing RES+ when there is no
longer a vehicle ahead or the
vehicle ahead is pulling away
and the brake is not applied with
cause the ACC to resume.
When it is determined that there is
no vehicle ahead or the vehicle
ahead is beyond the selected
following gap, then the vehicle
speed will increase to the set speed.
Reducing Speed While ACC Is at a
Set Speed
If ACC is already activated, do one
of the following:
. Use the brake to get to the
desired lower speed. Release
the brake and press SET–. The
vehicle will now cruise at the
lower speed.
. Press and hold SET– until the
desired lower speed is reached,
then release it.
. To decrease the vehicle speed in
smaller increments, press SET−
briefly. For each press, the
vehicle goes about 1 km/h
(1 mph) slower. .
To decrease the vehicle speed in
larger increments, hold SET−.
While holding SET−, the vehicle
speed decreases to the next
5 km/h (5 mph) step, then
continues to decrease by 5 km/h
(5 mph) at a time.
The set speed can also be
decreased while the vehicle is
stopped.
. If stopped with the brake
applied, press or hold SET− until
the desired set speed is
displayed.
Selecting the Follow Distance Gap
When a slower moving vehicle is
detected ahead within the selected
following gap, ACC will adjust the
vehicle's speed and attempt to
maintain the follow distance gap
selected.
Press
[on the steering wheel to
adjust the following gap. Each press
cycles the gap button through three
settings: Far, Medium, or Near. When pressed, the current gap
setting displays briefly on the
instrument cluster. The gap setting
will be maintained until it is
changed.
Since each gap setting corresponds
to a following time (Far, Medium,
or Near), the following distance will
vary based on vehicle speed. The
faster the vehicle speed, the further
back 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 0268.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
250 Driving and Operating
Alerting the Driver
With Head-Up Display
Without 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 will flash on the windshield.
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 0156.
See Defensive Driving 0187. Approaching and Following a
Vehicle
The vehicle ahead indicator is in the
instrument cluster. It only displays
when a vehicle is detected in your
vehicle’s path moving in the same
direction. If this symbol is not
displaying, ACC will not respond to
or brake for vehicles ahead.
ACC automatically slows the vehicle
down and adjusts vehicle speed to
follow a detected vehicle ahead at
the selected following gap. The
vehicle speed increases or
decreases to follow a detected
vehicle in front of your vehicle when
that vehicle is traveling slower than
your vehicle set speed. It may apply
limited braking, if necessary. When
braking is active, the brake lamps
will come on. The automatic braking
may feel or sound different than if
the brakes were applied manually.
This is normal.
Stationary or Very Slow-Moving
Objects
{Warning
ACC may not detect and react to
stopped or slow-moving vehicles
ahead of you. For example, the
system may not brake for a
vehicle it has never detected
moving. This can occur in
stop-and-go traffic or when a
vehicle suddenly appears due to
a vehicle ahead changing lanes.
Your vehicle may not stop and
could cause a crash. Use caution
when using ACC. Your complete
attention is always required while
driving and you should be ready
to take action and apply the
brakes.