2021 CHEVROLET SUBURBAN light

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
258 Driving and Operating
Irregular Objects Affecting ACC
ACC may have difficulty detecting the
following objects:
.Vehicles with cargo extending from the
back end.
.Non-standard shaped vehicles, such as
vehicle transport, vehicles with a side car
fitted, or horse carriages.
.Objects that are close to the front of your
vehicle.
ACC Automatically Disengages
ACC may automatically disengage and the
driver will need to manually apply the
brakes to slow the vehicle if:
.The sensors are blocked.
.The Traction Control System (TCS) or
StabiliTrak/ESC system has activated or
been disabled.
.There is a fault in the system.
.The radar falsely reports blockage when
driving in a desert or remote area with
no other vehicles or roadside objects.
A DIC message may display to indicate
that ACC is temporarily unavailable.
The ACC indicator will turn white when ACC
is no longer active. In some cases, when ACC is temporarily
unavailable, regular cruise control may be
used. See
“Switching Between ACC and
Regular Cruise Control” previously in this
section. Always consider driving conditions
before using either cruise control system.
Notification to Resume ACC
ACC will maintain a follow gap behind a
detected vehicle and slow your vehicle to a
stop behind that vehicle.
If the stopped vehicle ahead has driven
away and ACC has not resumed, the vehicle
ahead indicator will flash as a reminder to
check traffic ahead before proceeding. In
addition, the left and right sides of the
Safety Alert Seat will pulse three times,
or three beeps will sound. See ”Alert Type”
and “Adaptive Cruise Go Notifier” in
“Collision/Detection Systems” underVehicle
Personalization 0124.
When the vehicle ahead drives away, press
RES+ or the accelerator pedal to resume
ACC. If stopped for more than two minutes
or if the driver door is opened and the
driver seat belt is unbuckled, the ACC
automatically applies the Electric Parking
Brake (EPB) to hold the vehicle. The EPB
status light will turn on. See Electric Parking
Brake 0240. A DIC warning message may display
indicating to shift to P (Park) before exiting
the vehicle. See
Vehicle Messages 0124.
{Warning
If ACC has stopped the vehicle, and if ACC
is disengaged, turned off, or canceled, the
vehicle will no longer be held at a stop.
The vehicle can move. When ACC is
holding the vehicle at a stop, always be
prepared to manually apply the brakes.
{Warning
Leaving the vehicle without placing it in
P (Park) can be dangerous. Do not leave
the vehicle while it is being held at a
stop by ACC. Always place the vehicle in
P (Park) and turn off the ignition before
leaving the vehicle.
ACC Override
If using the accelerator pedal while ACC is
active, the ACC indicator turns blue on the
instrument cluster indicating ACC braking
will not occur. ACC will resume operation
when the accelerator pedal is not being
pressed.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
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260 Driving and Operating
ACC will not detect a vehicle ahead until it
is completely in the lane. The brakes may
need to be manually applied.
Objects Not Directly in Front of Your Vehicle
The detection of objects in front of the
vehicle may not be possible if:
.The vehicle or object ahead is not within
your lane.
.The vehicle ahead is shifted, not centered,
or is shifted to one side of the lane.
Driving in Narrow Lanes
Vehicles in adjacent traffic lanes or roadside
objects may be incorrectly detected when
located along the roadway.
Do Not Use ACC on Hills and When Towing a
Trailer
Do not use ACC when driving on steep hills
or when towing a trailer. ACC will not detect
a vehicle in the lane while driving on steep
hills.
Disengaging ACC
There are three ways to disengage ACC:
.Step lightly on the brake pedal.
.Press*.
.PressJ.
Erasing Speed Memory
The ACC set speed is erased from memory if
Jis pressed or if the ignition is turned off.
Weather Conditions Affecting ACC
System operation may be limited under
snow, heavy rain, or road spray conditions.
Accessory Installations and Vehicle
Modifications
Do not install or place any object around
the front camera windshield area that would
obstruct the front camera view.
Do not install objects on top of the vehicle
that overhang and obstruct the front
camera, such as a canoe, kayak, or other
items that can be transported on a roof rack
system. See Roof Rack System 092. Do not modify the hood, headlamps, or fog
lamps, as this may limit the camera’s ability
to detect an object.
Cleaning the Sensing System
The camera sensor on the windshield behind
the rearview mirror, and the sensors on the
front of the vehicle can become blocked by
snow, ice, dirt, mud, or debris. This area
needs to be cleaned for ACC to operate
properly.
If ACC will not operate, regular cruise control
may be available. See
“Switching Between
ACC and Regular Cruise Control” previously
in this section. Always consider driving
conditions before using either cruise control
system.
For cleaning instructions, see “Washing the
Vehicle” underExterior Care 0376.
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.

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Driving and Operating 265
Warning (Continued)
mirrors and glance over your shoulder.
Improper use could result in serious
injury to you or others.
Park Assist
The vehicle may be equipped with the Rear
Park Assist (RPA) and Front Park Assist (FPA).
The Park Assist system may provide
assistance to driver while backing up and
parking. Park Assist uses ultrasonic sensors
in the bumper to measure the distance
between the vehicle and objects. The system
calculates the distance between vehicle and
object via measuring the time it takes for
the ultrasonic waves to bounce back from
the object. Park Assist works only at speeds
up to about 11 Km/h (7 mph). An illuminated
indicater light in the parking system is
ready to operate. The sensors on the
bumpers may detect objects up to 1.8m
(6 ft) behind and 1.25m (4 ft) in front of the
vehicle within a one 25 cm (10) 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 wash in freezing
temperatures.
{Warning
The Park Assist System is no substitute
for careful and attentive driving. The Park
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 11 km/h
(7 mph). To prevent injury, death,
or vehicle damage, even with Park Assist,
always check the area around the vehicle
and check all mirrors before moving
forward or backing.
How the system works
The instrument cluster may have a Park
Assist display with bars that show distance
to object, driving direction, and object
location information for the Park 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 very close to the vehicle
rear (<0.6m (2 ft)), five beeps will sound
from the rear followed by a continuous
beep from the rear, or both sides of the
Safety Alert Seat will pulse five times. When
an object is very close to the vehicle front
(<0.3m (1 ft)), a continuous beep will sound
from the front, or both sides of the Safety
Alert Seat will pulse five times. Beeps for
FPA are higher pitched than for RPA.
Rear Cross Traffic Alert (RCTA)
If equipped, when the vehicle is shifted into
R (Reverse), RCTA displays a red warning
triangle with a left or right pointing arrow
to warn of traffic coming from the left or
right. This system detects objects coming
from up to 20 m (65 ft) from the left or
right side of the vehicle. When an object is
detected, either three beeps sound from the

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
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Driving and Operating 267
Warning (Continued)
To help avoid death or injury, always
check for pedestrians around the vehicle
before backing up. Be ready to take
action and apply the brakes. See
Defensive Driving0214. Keep the RVC,
taillamps, and back-up lamps clean and in
good repair.
Rear Pedestrian Alert can be set to Off or
Alert. See “Rear Pedestrian Detection” in
“Collision/Detection Systems” underVehicle
Personalization 0124. If equipped, alerts can
be set to beeps or seat pulses. See “Alert
Type” in“Collision/Detection Systems” under
Vehicle Personalization 0124.
Assistance Systems for Driving
If equipped, when driving the vehicle in a
forward gear, Forward Collision Alert (FCA),
Front Pedestrian Braking (FPB), Lane Keep
Assist (LKA), Side Blind Zone Alert (SBZA),
Lane Change Alert (LCA), and/or Automatic
Emergency Braking (AEB) 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). If the vehicle
has Adaptive Cruise Control (ACC), it can
detect vehicles to distances of approximately
110 m (360 ft) and operates at all speeds.
See Adaptive Cruise Control (Advanced)
0 253.
{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
(Continued)
Warning (Continued)
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. SeeDefensive Driving
0 214.
FCA can be disabled with either the FCA
steering wheel control or, if equipped,
through vehicle personalization. See
“Collision/Detection Systems” underVehicle
Personalization 0124.
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

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
272 Driving and Operating
8 km/h (5 mph) and 80 km/h (50 mph).
Automatic braking levels may be reduced
under certain conditions, such as higher
speeds.
If this happens, Automatic Braking may
engage the Electric Parking Brake (EPB) to
hold the vehicle at a stop. Release the EPB.
A firm press of the accelerator pedal will
also release Automatic Braking and the EPB.
{Warning
FPB may alert or automatically brake the
vehicle suddenly in situations where it is
unexpected and undesired. It could falsely
alert or brake for objects similar in shape
or size to pedestrians, including shadows.
This is normal operation and the vehicle
does not need service. To override
Automatic Braking, firmly press the
accelerator pedal, if it is safe to do so.
Automatic Braking can be disabled through
vehicle personalization. See “Front Pedestrian
Detection” in“Collision/Detection Systems”
under Vehicle Personalization 0124.
{Warning
Using the Front Pedestrian Braking
system 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.
Cleaning the System
If FPB does not seem to operate properly,
cleaning the outside of the windshield in
front of the rearview mirror may correct the
issue.
Side Blind Zone Alert (SBZA)
If equipped, the SBZA system is a
lane-changing aid that assists drivers with
avoiding crashes that occur with moving
vehicles in the side blind zone, or blind spot
areas. When the vehicle is in a forward gear,
the left or right side mirror display will light
up if a moving vehicle is detected in that
blind zone. If the turn signal is activated and
a vehicle is also detected on the same side,
the display will flash as an extra warning
not to change lanes. Since this system is
part of the Lane Change Alert (LCA) system,
read the entire LCA section before using this
feature.
Lane Change Alert (LCA)
If equipped, the Lane Change Alert (LCA)
system is a lane-changing aid that can assist
drivers with avoiding lane change crashes
with moving vehicles in the side blind zone,
or blind spot areas or with vehicles rapidly
approaching these areas from behind. When
a vehicle is detected in the blind zone, the
LCA warning display will light up in the
corresponding side mirror and will flash if
the turn signal is on. The Side Blind Zone
Alert (SBZA) system is included as part of
the LCA system.
{Warning
LCA does not alert the driver to vehicles
outside of the system detection zones,
pedestrians, bicyclists, or animals. It may
not provide alerts when changing lanes
under all driving conditions. Failure to use
proper care when changing lanes may
result in injury, death, or vehicle damage.
Before making a lane change, always
check mirrors, glance over your shoulder,
and use the turn signals.

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Driving and Operating 273
LCA Detection Zones
1. SBZA Detection Zone
2. LCA Detection Zone
When towing a trailer, LCA feature is
disabled. When not towing a trailer, the LCA
sensor covers a zone of approximately one
lane over from both sides of the vehicle,
or 3.5 m (11 ft). The height of the zone is
approximately between 0.5 m (1.5 ft) and
2 m (6 ft) off the ground. Drivers are also
warned of vehicles rapidly approaching this
area up to approximately 70 m (230 ft)
behind the vehicle.
Extended Side Blind Zone Area (ESBZA)
If equipped, the ESBZA system is a
lane-changing aid that assists drivers with
avoiding crashes that occur with moving
vehicles in the side blind zone, or blind spotareas. The extended side blind zone area
adds the blind zone area along the side of a
trailer that the host vehicle is pulling.
When the vehicle is in a forward gear, the
left or right side mirror display will light up
if a moving vehicle is detected in that
extended blind zone. If the turn signal is
activated and a vehicle is also detected on
the same side, the display will flash as an
extra warning not to change lanes. Since
this system is part of the Lane Change Alert
system, read the entire Lane Change Alert
section before using this feature.
{Warning
ESBZA does not alert the driver to
vehicles outside of the system detection
zones, pedestrians, bicyclists, or animals.
It may not provide alerts when changing
lanes under all driving conditions. Failure
to use proper care when changing lanes
may result in injury, death, or vehicle
damage. Before making a lane change,
always check mirrors, glance over your
shoulder, and use the turn signals.
ESBZA Detection Zones
1. SBZA Detection Zone
2. ESBZA Detection Zone
3. LCA Detection Zone
The Side Blind Zone Alert (SBZA) warning
area starts at approximately the middle of
the vehicle and goes back 5 m (16 ft). The
Extended Side Blind Zone Alert (ESBZA)
warning area starts at approximately 3 m
(10 ft) to the trailing edge of the vehicle and
goes back up to 21 m (69 ft) behind the
vehicle. The maximum trailer length is
12 m (39 ft).
How the System Works
The LCA/ESBZA symbol lights up in the side
mirrors when the system detects a moving
vehicle in the next lane over that is in the
extended side blind zone. This indicates it
may be unsafe to change lanes. Before

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
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274 Driving and Operating
making a lane change, check the SBZA
display, check mirrors, glance over your
shoulder, and use the turn signals.
Left Side MirrorDisplayRight Side Mirror Display
When the vehicle is started, both outside
mirror LCA/ESBZA displays will briefly come
on to indicate the system is operating.
When the vehicle is in a forward gear, the
left- or right-side mirror display will light up
if a moving vehicle is detected in that blind
zone. If the turn signal is activated in the
same direction as a detected vehicle, this
display will flash as an extra warning not to
change lanes.
LCA/ESBZA displays may not come on when
passing a vehicle quickly, or when passing a
stopped vehicle. LCA/ESBZA may alert to
objects attached to the vehicle, such as a
bicycle, or object extending out to either side of the vehicle or trailer. This is normal
system operation; the vehicle does not need
service.
LCA/ESBZA can be disabled through vehicle
personalization. See
“Collision/Detection
Systems” underVehicle Personalization
0 124. If SBZA is disabled by the driver, the
ESBZA mirror displays will not light up.When the System Does Not Seem to
Work Properly
LCA/ESBZA displays may not come on when
passing a vehicle quickly, or when passing a
stopped vehicle. The LCA/ESBZA detection
zones that extend back from the side of the
vehicle do not move further back when a
trailer is towed. Use caution while changing
lanes when towing a trailer. LCA/ESBZA may
alert to objects attached to the vehicle, such
as a trailer, bicycle, or object extending out
to either side of the vehicle or trailer. This is
normal system operation; the vehicle does
not need service.
LCA/ESBZA may not always alert the driver
to vehicles in the side blind zone, especially
in wet conditions. The system does not need
to be serviced. The system may light up due to guardrails, signs, trees, shrubs, and other
non-moving objects. This is normal system
operation; the vehicle does not need service.
LCA/ESBZA may not operate when the LCA/
ESBZA sensors in the left or right corners of
the rear bumper are covered with mud, dirt,
snow, ice, or slush, or in heavy rainstorms.
For cleaning instructions, see "Washing the
Vehicle" under
Exterior Care0376. If the DIC
displays the system unavailable message
after cleaning both sides of the vehicle
toward the rear corners of the vehicle, see
your dealer.
If the DIC displays the system unavailable
message after cleaning both sides of the
vehicle toward the rear corners of the
vehicle, see your dealer
If the LCA/ESBZA displays do not light up
when vehicles are in the blind zone and the
system is clean, the system may need
service. Take the vehicle to your dealer.
When ESBZA is disabled for any reason
other than the driver turning it off, the
Extended Side Blind Zone Alert On option
will not be available on the
personalization menu.

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276 Driving and Operating
audible alert or the driver seat may pulse
indicating that a lane marking has been
crossed.
To turn LKA on and off, press
Ato the
left of the steering wheel. If equipped, the
indicator light on the button comes on
when LKA is on and turns off when LKA is
disabled.
When on,
Ais white, if equipped,
indicating that the system is not ready to
assist.
Ais green if LKA is ready to
assist. LKA may assist by gently turning the
steering wheel if the vehicle approaches a
detected lane marking.
Ais amber when
assisting. It may also provide a Lane
Departure Warning (LDW) alert by flashing
Aamber if the vehicle crosses a
detected lane marking. Additionally, there
may be three beeps, or the driver seat may
pulse three times, on the right or left,
depending on the lane departure direction.
Take Steering
The LKA system does not continuously steer
the vehicle. If LKA does not detect active
driver steering, an alert and chime may be
provided. Steer the vehicle to dismiss. LKA
may become temporarily unavailable after
repeated take steering alerts.
When the System Does Not Seem to
Work Properly
The system performance may be
affected by:
.Close vehicles ahead.
.Sudden lighting changes, such as when
driving through tunnels.
.Banked roads.
.Roads with poor lane markings, such as
two-lane roads.
If the LKA system is not functioning
properly when lane markings are clearly
visible, cleaning the windshield may help.
A camera blocked message may display if
the camera is blocked. Some driver
assistance systems may have reduced
performance or not work at all. An LKA or
LDW unavailable message may display if the
systems are temporarily unavailable. This
message could be due to a blocked camera.
The LKA system does not need service. Clean
the outside of the windshield behind the
rearview mirror.
LKA assistance and/or LDW alerts may occur
due to tar marks, shadows, cracks in the
road, temporary or construction lane
markings, or other road imperfections. This is normal system operation; the vehicle does
not need service. Turn LKA off if these
conditions continue.
Fuel
Top Tier Fuel
GM recommends the use of TOP TIER
Detergent Gasoline to keep the engine clean,
reduce engine deposits, and maintain
optimal vehicle performance. Look for the
TOP TIER Logo or see www.toptiergas.com
for a list of TOP TIER Detergent Gasoline
marketers and applicable countries.