brake sensor GMC SIERRA 2021 Owner's Manual

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Introduction 5
1. Tow/Haul Mode (On Some Models). SeeDriver Mode Control 0251.
Automatic Transfer Case Control (If
Equipped). See Four-Wheel Drive 0242.
Driver Mode Control 0251 (If Equipped).
2. Air Vents 0209.
3. Head-Up Display (HUD) 0128 (If
Equipped).
4. Turn Signal Lever. See Turn and
Lane-Change Signals 0143.
Windshield Wiper/Washer 0101.
5. Instrument Cluster 0106.
6. Shift Lever. See Automatic Transmission
0 239.
Range Selection Mode. See Manual Mode
0 241.
7. Light Sensor. See Automatic Headlamp
System 0142.
8. Infotainment Controls. See Overview
0 149.
9. Climate Control Systems 0204 (If
Equipped).
Dual Automatic Climate Control System
0 206 (If Equipped).
10. Heated and Ventilated Front Seats 052
(If Equipped). 11.ALane Keep Assist (LKA)
0281 (If
Equipped).
XPark Assist Switch (If Equipped). See
Assistance Systems for Parking or Backing
0 266.
hAuto Stop Disable Switch (If
Equipped). See Stop/Start System 0233.
5Power Release Tailgate (If
Equipped). See Tailgate023.
|Hazard Warning Flashers 0142.
gTraction Control/Electronic Stability
Control 0248.
ADC/AC Switch. See Power Outlets
0 102.
5Hill Descent Control Switch (If
Equipped). See Hill Descent Control (HDC)
0 250.
jPower Assist Steps 030 (If
Equipped).
LExpress Window Down Button (If
Equipped). See Power Windows 041.
Tow/Haul Mode 0242 (On Some
Models).
Exhaust Brake (If Equipped). See Duramax
Diesel Supplement. Power Take-Off (PTO) (If Equipped). See
Duramax Diesel Supplement.
12. Power Outlet (Alternating Current) (If Equipped). See Power Outlets0102.
13. Power Outlet (Direct Current) Power
Outlets 0102.
14. USB Port 0158.
15. Wireless Charging 0103 (If Equipped).
16. Trailer Brake Control Panel (If Equipped). See“Integrated Trailer Brake Control
System” underTowing Equipment 0296.
17. ENGINE START/STOP. See Ignition
Positions (Keyless Access) 0230 or
Ignition Positions (Key Access) 0229.
18. Steering Wheel Controls 0100 (If
Equipped).
Driver Information Center (DIC) Controls.
See Driver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
19. Horn 0101.
20. Hood Release. See Hood0323.
21. Steering Wheel Adjustment 0100 (Out
of View).

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
256 Driving and Operating
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) 0250, Automatic
Transmission 0239, and Tow/Haul Mode
0 242.
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, press5.
Erasing Speed Memory
The cruise control set speed is erased from
memory if
5is pressed or the ignition is
turned off.
Adaptive Cruise Control (Camera)
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 0248. 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 0213.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 257
{Warning
ACC will not detect or brake for children,
pedestrians, animals, or other objects.
Do not use ACC when:
.On winding and hilly roads or when
the camera sensor is blocked by snow,
ice, or dirt. The system may not
detect a vehicle ahead. Keep the
windshield and headlamps clean.
.When visibility is poor due to rain,
snow, fog, dirt, insect residue, or dust;
when other foreign objects obscure
the camera’s view; or when the
vehicle in front or oncoming traffic
causes additional environmental
obstructions, such as road spray. ACC
performance is limited under these
conditions.
.On slippery roads where fast changes
in tire traction can cause excessive
wheel slip
.With extremely heavy cargo loaded in
the cargo area or rear seat
.When towing a trailer
J:Press to turn the system on or off. The
indicator turns white on the instrument
cluster when ACC is turned on.
RES+ : Press briefly to resume the previous
set speed or to increase vehicle speed if ACC
is already activated. To increase speed by
about 1 km/h (1 mph), press RES+ briefly. To
increase speed to the next 5 km/h (5 mph)
mark on the speedometer, hold RES+.
SET– :Press briefly to set the speed and
activate ACC or to decrease vehicle speed if
ACC is already activated. To decrease speed
by about 1 km/h (1 mph), press SET– briefly.
To decrease speed to the next 5 km/h
(5 mph) mark on the speedometer,
hold SET–.
*: Press to disengage ACC without erasing
the selected set speed.
[: Press to select a following gap setting
for ACC of Far, Medium, or Near.
The speedometer reading can be displayed
in either English or metric units. See
Instrument Cluster 0106. The increment
value used depends on the units displayed.
Switching Between ACC and Regular Cruise
Control
To switch between ACC and regular cruise
control, press and hold
*. A Driver
Information Display (DIC) message displays.
See Vehicle Messages 0130.
ACC IndicatorRegular Cruise Control
Indicator
When ACC is engaged, a green
oindicator
will be lit on the instrument cluster and the
following gap will be displayed. When the

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 265
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 0213.
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. (Continued)
Warning (Continued)
.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.
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 0131. 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 0131.
Cleaning
Depending on vehicle options, keep these
areas of the vehicle clean to ensure the best
driver assistance feature performance. Driver
Information Center (DIC) messages may
display when the systems are unavailable or
blocked.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 275
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).
{Warning
FCA 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(Continued)
Warning (Continued)
objects. Be ready to take action and
apply the brakes. SeeDefensive Driving
0 213.
FCA can be disabled through vehicle
personalization. See “Collision/Detection
Systems” underVehicle Personalization
0 131.
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,
or ice, or if the windshield is damaged.
It may also not detect a vehicle on
winding or hilly roads, or in conditions
that can limit visibility such as fog, rain,
or snow, or if the headlamps or
windshield are not cleaned or in proper
condition. Keep the windshield,
headlamps, and FCA sensors clean and in
good repair.
Collision Alert
With Head-Up Display

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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276 Driving and Operating
Without Head-Up Display
When your vehicle approaches another
detected vehicle too rapidly, the red FCA
display will flash on the windshield. Also,
eight rapid high-pitched beeps will sound
from the front, or both sides of the Safety
Alert Seat will pulse five times. When this
Collision Alert occurs, the brake system may
prepare for driver braking to occur more
rapidly which can cause a brief, mild
deceleration. Continue to apply the brake
pedal as needed. Cruise control may be
disengaged when the Collision Alert occurs.
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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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278 Driving and Operating
AEB and IBA can be disabled. See“Collision/
Detection Systems” underVehicle
Personalization 0131.
{Warning
Using AEB or IBA while towing a trailer
could cause you to lose control of the
vehicle and crash. Turn the system to
Alert or Off when towing a trailer.
A system unavailable message may
display if:
.The front of the vehicle or windshield is
not clean.
.Heavy rain or snow is interfering with
object detection.
.There is a problem with the StabiliTrak/
Electronic Stability Control (ESC) system.
The AEB system does not need service.
Front Pedestrian Braking (FPB)
System
If equipped, the FPB system may help avoid
or reduce the harm caused by front-end
crashes with nearby pedestrians when
driving in a forward gear. FPB displays an
amber indicator,
~, when a nearby
pedestrian is detected ahead. When approaching a detected pedestrian too
quickly, FPB provides a red flashing alert on
the windshield and rapidly beeps or pulses
the driver seat. FPB can provide a boost to
braking or automatically brake the vehicle.
This system includes Intelligent Brake Assist
(IBA), and the Automatic Emergency Braking
(AEB) system may also respond to
pedestrians. See
Automatic Emergency
Braking (AEB) 0277.
The FPB system can detect and alert to
pedestrians in a forward gear at speeds
between 8 km/h (5 mph) and 80 km/h
(50 mph). During daytime driving, the
system detects pedestrians up to a distance
of approximately 40 m (131 ft). During
nighttime driving, system performance is
very limited.
{Warning
FPB does not provide an alert or
automatically brake the vehicle, unless it
detects a pedestrian. FPB may not detect
pedestrians, including children:
.When the pedestrian is not directly
ahead, fully visible, or standing
upright, or when part of a group. (Continued)
Warning (Continued)
.Due to poor visibility, including
nighttime conditions, fog, rain,
or snow.
.If the FPB sensor is blocked by dirt,
snow, or ice.
.If the headlamps or windshield are not
cleaned or in proper condition.
Be ready to take action and apply the
brakes. For more information, see
Defensive Driving 0213. Keep the
windshield, headlamps, and FPB sensor
clean and in good repair.
FPB can be set to Off, Alert, or Alert and
Brake through vehicle personalization. See
“Collision/Detection Systems” underVehicle
Personalization 0131.
Detecting the Pedestrian Ahead

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 309
2. Touch Import Profile on the pop-up.
3. Select a trailer profile from the list.
4. Touch IMPORT.
A pop-up will indicate the import was
successful. Touch OK to return to the trailer
list and select the trailer profile. The Tow/
Haul Mode reminder, Brake Gain Setting and
Trailer Tire Pressure sensor learning,
if equipped, do not import.
Trailer Feature Setup
Tow/Haul Mode Reminder
To turn the Tow/Haul Mode Reminder
setting on, touch Yes. To turn it off,
touch No.
Trailer Tire Pressure Setup
If the Trailer Tire Pressure Monitoring
System (TTPMS) is detected, touch the Tire
Pressure Monitoring icon to set up tire
pressure monitoring. Touch Yes to set up
the sensors or touch No to return to the
previous screen.
The trailer tire pressure sensors can transmit
up to 7 m (23 feet) from the hitch receiver of
the vehicle. A trailer must be electrically connected to
the vehicle before starting the
sensor-to-vehicle learn process.
After selecting Start from the Learn Sensors
screen, use the Tool Method or the Manual
Method (described below) to learn each tire
sensor, during which the current tire number
will be highlighted.
Each sensor has a minimum of two minutes
to learn, shown by a timer. After a sensor is
learned, a checkmark appears next to the
tire, the vehicle horn will sound, the
vehicle’s brake lamps will flash, and all
working trailer lamps will flash. It then
moves to the next sensor.
To cancel the process touch Stop.
The recommended tire pressure must be
entered for the trailer tires. This allows the
vehicle to alert when the tire pressure is
high or low.
TTPMS must learn the location of the
installed tire sensors to show correct air
pressure and temperature for each tire. To
set up, use one of the following options or
see a tire or trailer dealer for service. The
learning process must be repeated when thetrailer tires are rotated or replaced. See
“Editing a Trailer Profile”
later in this section
for tire pressure sensor relearn information.
Tool Method: A TTPMS activation tool can
be purchased separately to learn the sensor
locations.
Manual Method: Without the tool, the air
pressure can be increased or decreased in
each tire for 10 seconds. Do not exceed the
maximum inflation pressure found on the
tire sidewalls. Make sure to re-adjust tire
pressure to the recommended level when
the process is complete.
Sensor Learning Steps
To complete the sensor-to-vehicle learn
process:
1. Touch Start on the Learn Sensors screen. The horn chirps twice and the Learning
Active screen appears on the
infotainment display.
2. Start with the driver side front trailer tire.
3. Activate the tool near the valve stem or adjust the air pressure of this tire until
the horn chirps and all working vehicle
and trailer lights flash.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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Driving and Operating 315
No Trailer Connected
When there is no trailer connected, Trailer
Profiles cannot be activated but most
options can be edited.
Trailer Brake Gain Memory
The system can memorize the brake gain
setting of a Trailer Profile or a Guest Trailer
Profile. When a Trailer Profile or Guest
Trailer Profile is selected, and a brake gain
setting is set for that Trailer Profile, a quick
notice will appear to indicate that the
system has recalled that profile’s brake gain
setting.
If a Trailer Profile is already active and the
brake gain setting had been set for that
Trailer Profile, the quick notice will trigger
whenever the ignition is turned on.
If there was an error in setting the brake
gain for a Trailer Profile, there will be a
notification. This pop-up will not appear if
the Guest Trailer Profile is active or if there
is no trailer connected.
Trailer brake gain should be set for a specific
trailering condition and must be adjusted
anytime vehicle loading, trailer loading,
or road surface conditions change.Editing a Trailer Profile
Trailer Profile View
Touch to edit any of the following options
in the Trailer Profile view:
.Trailer Name
.Towing Assistance Setup, if equipped
.Tire Pressure Setup, if equipped
.Trailer Maintenance
.Edit Mileage
.Reset Average Fuel Economy
Touch Save to save the new value to the
Trailer Profile. Touching Back will still save
the previously entered information.
Trailer Name
Touch to edit the Trailer Profile’s name. Use
at least one character and no spaces.
Touch Save.
Towing Assistance Setup
A trailer should be connected to complete
this portion of profile setup.
Touch to set up towing assistance features
for the Trailer Profile. See "Towing
Assistance" for details on the setup. Tire Pressure Setup
Touch to set up the Trailer Tire Pressure
Monitoring System (TTPMS) for the Trailer
Profile. See
“Trailer Tire Pressure Setup”
previously in this section for details on the
setup. Also, touch Tire Pressure Setup if the
trailer tires were rotated or if the tire
pressure sensors in the tires were replaced
for this Trailer Profile. The vehicle will need
to relearn the tire sensors and their
locations.
If TTPMS had been set up previously, the
Select Number of Sensors screen will appear
after touching Tire Pressure Setup. If the
number of sensors has changed, select the
number and touch Next.
If a new number of sensors is selected, the
Relearn Sensors pop-up will appear. Touch
Cancel to go back or touch Relearn to
overwrite the current sensors and begin the
relearning process. See “Trailer Tire Pressure
Setup” previously in this section.
If number of sensors has not changed, touch
Next and the Learn sensors screen will
appear.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
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342 Vehicle Care
Brake Pedal Travel
See your dealer if the brake pedal does not
return to normal height, or if there is a
rapid increase in pedal travel. This could be
a sign that brake service may be required.
Replacing Brake System Parts
Always replace brake system parts with
new, approved replacement parts. If this is
not done, the brakes may not work
properly. The braking performance can
change in many ways if the wrong brake
parts are installed or if parts are improperly
installed.
Brake Pad Life System
When to Change Brake Pads
This vehicle has a system that estimates the
remaining life of the front and rear brake
pads. Brake pad life is displayed in the
Driver Information Center (DIC), along with
a percentage for each axle. The system must
be reset every time the brake pads are
changed.
When the system has determined that the
brake pads need to be replaced, a message
will display, which may include mileage
remaining.Brake pads should always be replaced as
complete axle sets.
How to Reset the Brake Pad Life System
The system will automatically detect when
significantly worn brake pads are replaced.
When the ignition is turned on after new
pads and wear sensors are installed, a
message will display. Follow the prompts to
reset the system.
The brake pad life system can also be
manually reset:
1. Display Brake Pad Life on the DIC. See Driver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
2. Press the thumbwheel or the trip odometer reset stem if the vehicle does
not have DIC buttons. Select front or rear
pads as appropriate.
3. Select YES on the confirmation message, or press the trip odometer reset stem on
a base level DIC. Repeat for pads on the
other axle if they were also replaced.
How to Disable the Brake Pad Life
System
The brake pad life system can be turned off.
This may be necessary if aftermarket brake
pads without wear sensors are installed.
When the system is turned off, the front
and rear brake pad life percentages will not
display. However, the built-in wear
indicators that make a high-pitched warning
sound when the brake pads are worn can
still determine when the pads should be
replaced. See Brakes0341.
To turn off the brake pad life system: 1. Display Brake Pad Life on the DIC. See Driver Information Center (DIC) (Base
Level) 0124 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0125.
2. Select DISABLE.
To turn the brake pad life system back on,
follow the above steps but select ENABLE in
Step 2.