2020 GMC SIERRA speed sensor

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
76 Seats and Restraints
When Should an Airbag
Inflate?
This vehicle is equipped with
airbags. SeeAirbag System 072.
Airbags are designed to inflate if the
impact exceeds the specific airbag
system's deployment threshold.
Deployment thresholds are used to
predict how severe a crash is likely
to be in time for the airbags to
inflate and help restrain the
occupants. The vehicle has
electronic sensors that help the
airbag system determine the
severity of the impact. Deployment
thresholds can vary with specific
vehicle design.
Frontal airbags are designed to
inflate in moderate to severe frontal
or near frontal crashes to help
reduce the potential for severe
injuries, mainly to the driver's or
front outboard passenger's head
and chest.
Whether the frontal airbags will or
should inflate is not based primarily
on how fast the vehicle is traveling. It depends on what is hit, the
direction of the impact, and how
quickly the vehicle slows down.
Frontal airbags may inflate at
different crash speeds depending on
whether the vehicle hits an object
straight on or at an angle, and
whether the object is fixed or
moving, rigid or deformable, narrow
or wide.
Frontal airbags are not intended to
inflate during vehicle rollovers, rear
impacts, or many side impacts.
In addition, the vehicle has
advanced technology frontal
airbags. Advanced technology
frontal airbags adjust the restraint
according to crash severity.
Seat-mounted side impact airbags
are designed to inflate in moderate
to severe side crashes depending
on the location of the impact.
Seat-mounted side impact airbags
are not designed to inflate in frontal
impacts, near frontal impacts,
rollovers, or rear impacts.
A seat-mounted side impact airbag
is designed to inflate on the side of
the vehicle that is struck.
Roof-rail airbags are designed to
inflate in moderate to severe side
crashes depending on the location
of the impact. In addition, these
roof-rail airbags are designed to
inflate during a rollover or in a
severe frontal impact. Roof-rail
airbags are not designed to inflate in
rear impacts. Both roof-rail airbags
will inflate when either side of the
vehicle is struck or if the sensing
system predicts that the vehicle is
about to roll over on its side, or in a
severe frontal impact.
In any particular crash, no one can
say whether an airbag should have
inflated simply because of the
vehicle damage or repair costs.
What Makes an Airbag
Inflate?
In a deployment event, the sensing
system sends an electrical signal
triggering a release of gas from the
inflator. Gas from the inflator fills the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Lighting 167
Keep this area of the windshield
clear of debris to allow for best
system performance.
The high-beam headlamps remain
on, under the automatic control,
until one of the following situations
occurs:
.The system detects an
approaching vehicle's
headlamps.
. The system detects a preceding
vehicle's taillamps.
. The outside light is bright
enough that high-beam
headlamps are not required.
. The vehicle's speed drops below
20 km/h (12 mph).
. The IntelliBeam system is
disabled by the button on the
turn signal lever. If this happens,
press the button on the end of
the turn signal lever when the
exterior lamp control is in the
AUTO or
2position. The
instrument cluster light will come
on to indicate the IntelliBeam is reactivated. See
Headlamp
High/Low-Beam Changer 0167
and
Flash-to-Pass 0168.
The high beams may not turn off
automatically if the system cannot
detect another vehicle's lamps
because of any of the following:
. The other vehicle's lamps are
missing, damaged, obstructed
from view, or otherwise
undetected.
. The other vehicle's lamps are
covered with dirt, snow, and/or
road spray.
. The other vehicle's lamps cannot
be detected due to dense
exhaust, smoke, fog, snow, road
spray, mist, or other airborne
obstructions.
. The vehicle's windshield is dirty,
cracked, or obstructed by
something that blocks the view
of the light sensor. .
The vehicle is loaded such that
the front end points upward,
causing the light sensor to aim
high and not detect headlamps
and taillamps.
. Driving on winding or hilly roads.
The automatic high-beam
headlamps may need to be disabled
if any of the above conditions exist.
Exterior Lamps Off
Reminder
A reminder chime sounds when the
headlamps or parking lamps are
manually turned on, the ignition is
off, and a door is open. To disable
the chime, turn the lamps off.
Headlamp High/
Low-Beam Changer
Push the turn signal lever toward
the instrument panel to change the
headlamps from low to high beam.
Pull or push the turn signal lever to
return to low-beam headlamps.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Lighting 169
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
Daytime Running Lamps (DRL).
During that delay, the instrumentcluster may not be as bright as
usual. Make sure the instrument
panel illumination control is in the
full bright position. See
Instrument
Panel Illumination Control 0172.
When it is bright enough outside,
the headlamps will turn off or may
change to DRL.
The automatic headlamp system
turns off when the exterior lamp
control is turned to
Oor 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
O
or;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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
182 Climate Controls
Caution
Using a razor blade or sharp
object to clear the inside rear
window can damage the rear
window defogger. Repairs would
not be covered by the vehicle
warranty. Do not clear the inside
rear window with sharp objects.
Remote Start Climate Control
Operation : If equipped with remote
start, the climate control system
may run when the vehicle is started
remotely. If equipped with heated or
ventilated seats or a heated steering
wheel, these features may come on
during a remote start. See Remote
Vehicle Start 024, Heated and
Ventilated Front Seats 061, and
Heated Steering Wheel 0120.
Sensors
The solar sensor, on top of the
instrument panel near the
windshield, monitors the solar heat.
The climate control system uses the
sensor information to adjust the
temperature, fan speed,
recirculation, and air delivery mode
for best comfort.
Do not cover the sensor; otherwise
the automatic climate control system
may not work properly.
Air Vents
Use the sliding knobs on the center
and side air vents to change the
direction of the airflow.
Air vents blow warm air on the side
windows in cold weather. If Floor,
Defog, or Defrost modes are
selected, a small amount of air will
come from the vents close to the
window.
To close the front a/c vents, move
the sliding knobs to the full down
position.
To close the rear a/c vents, move
the sliding knobs to the full inboard
position.
Operation Tips
.
Clear away any ice, snow,
or leaves from air inlets at the
base of the windshield that could
block the flow of air into the
vehicle.
. Clear snow off the hood to
improve visibility and help
decrease moisture drawn into
the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 245
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
previously 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.
While going downhill, cruise braking
helps maintain 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.
For other forms of descent control,
see
Hill Descent Control (HDC)
0 237, Automatic Transmission
0 221, and Tow/Haul Mode 0226.
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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
256 Driving and Operating
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.
{Warning
Do 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. SeeDefensive Driving
0 187.
Under many conditions, these
systems will not: (Continued)
Warning (Continued)
.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.
. Work if the area surrounding
the detection sensor is
damaged or not properly
repaired.
(Continued)
Warning (Continued)
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” underVehicle
Personalization 0157.
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
0 157.
Cleaning
Depending on vehicle options, keep
these areas of the vehicle clean to
ensure the best driver assistance
feature performance. Driver

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
266 Driving and Operating
.The accessory trailer cameras
are swapped at the hitch
connector. Ensure that the
camera mounted to the rear of
the trailer is connected to the
rear trailer camera input.
. The accessory trailer camera is
mounted, angled or rotated
outside of the defined mounting
location (see camera installation
instructions).
Distortion may be observed in the
calibrated Transparent Trailer
View if:
. The accessory trailer camera is
mounted, angled or rotated
outside of the defined mounting
location (see camera installation
instructions).
The Transparent Trailer icon may
appear grayed out if:
. A compatible trailer profile is not
configured or a non-compatible
trailer profile is selected.
. The vehicle is in R (Reverse).
. The trailer is not connected. .
The accessory rear trailer
camera is not connected or
connected to the incorrect input.
The preview may not be provided or
the wrong preview may be
provided if:
. The accessory cameras are not
recognized. Ensure that the
accessory camera(s) are
connected and power cycle the
vehicle.
. The accessory trailer cameras
are swapped at the hitch
connector. Ensure that the
accessory camera(s) are
connected to the correct input.
. The accessory trailer camera(s)
are connected to the correct
camera input.
. The accessory trailer camera(s)
are not installed according to the
installation instructions.
A feature may be unavailable or not
activating as expected if:
. The customization is disabled.
Check the customization settings
where applicable. .
The accessory trailer cameras
are swapped at the hitch
connector. Ensure that the
accessory camera(s) are
connected to the correct camera
input.
A view may switch automatically if:
. The vehicle is shifted to
another gear.
Park Assist
With Front and Rear Park Assist, as
the vehicle moves at speeds of less
than 8 km/h (5 mph) the sensors on
the bumpers may detect objects up
to 1.2 m (4 ft) in front and 2.5 m (8 ft)
behind 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-13337776) - 2020 - CRC - 4/4/19
270 Driving and Operating
Tailgating Alert
The vehicle ahead indicator will
display amber when you are
following a vehicle ahead much too
closely.
Selecting the Alert Timing
The Collision Alert control is on the
steering wheel. Press
[to set the
FCA timing to Far, Medium, or Near.
The first button press shows the
current setting on the DIC.
Additional button presses will
change this setting. The chosen
setting will remain until it is changed
and will affect the timing of both the
Collision Alert and the Tailgating
Alert features. The timing of both
alerts will vary based on vehicle
speed. The faster the vehicle speed,
the farther away the alert will occur.
Consider traffic and weather
conditions when selecting the alert timing. The range of selectable alert
timings may not be appropriate for
all drivers and driving conditions.
If your vehicle is equipped with
Adaptive Cruise Control (ACC),
changing the FCA timing setting
automatically changes the following
gap setting (Far, Medium, or Near).
Following Distance Indicator
The following distance to a moving
vehicle ahead in your path is
indicated in following time in
seconds on the Driver Information
Center (DIC). The minimum
following time is 0.5 seconds away.
If there is no vehicle detected
ahead, or the vehicle ahead is out of
sensor range, dashes will be
displayed.
Unnecessary Alerts
FCA may provide unnecessary
alerts for turning vehicles, vehicles
in other lanes, objects that are not
vehicles, or shadows. These alerts
are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to
operate properly, this may correct
the issue:
.
Clean the outside of the
windshield in front of the
rearview mirror.
. Clean the entire front of the
vehicle.
. Clean the headlamps.
Automatic Emergency
Braking (AEB)
If the vehicle has Forward Collision
Alert (FCA), it also has AEB (1500
series only), 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