brake BUICK ENVISION 2021 Service Manual

Buick E2UB-N Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14583509) - 2021 - CRC - 1/8/21
216 Driving and Operating
*:Press to disengage ACC without erasing
the set speed from memory.
3: Press to select a following gap time (or
distance) setting for ACC of Far, Medium,
or Near.
The speedometer reading can be displayed
in either English or metric units. See
Instrument Cluster 089.
Switching Between ACC and Regular Cruise
Control
To switch between ACC and regular cruise
control, press and hold
*. A Driver
Information Center (DIC) message displays.
See Vehicle Messages 0108.
ACC IndicatorRegular Cruise Control
Indicator
When ACC is activated, a green
oindicator
will be lit on the instrument cluster and the
following gap will be displayed. When the regular cruise control is activated, a green
Jindicator will be lit on the instrument
cluster; the following gap will not display.
When the vehicle is turned on, the cruise
control mode will be set to the last mode
used before the vehicle was turned off.
{Warning
Always check the cruise control indicator
on the instrument cluster to determine
which mode cruise control is in before
using the feature. If ACC is not active, the
vehicle will not automatically brake for
other vehicles, which could cause an
accident if the brakes are not applied
manually. You and others could be
seriously injured or killed.
Setting Adaptive Cruise Control
If cruise control is on when not in use, the
cruise on/off control could get pressed and
cruise control could become active when not
desired. Keep the cruise control off when
cruise is not being used.
Select the set speed desired for cruise. This
is the vehicle speed when no vehicle is
detected in its path. While the vehicle is moving, ACC will not set
at a speed less than 5 km/h (3 mph),
although it can be resumed.
To set ACC:
1. Press
].
2. Get up to the desired speed.
3. Press and release SET– .
4. Remove foot from the accelerator.
After ACC is set, it may immediately apply
the brakes if a vehicle ahead is detected
closer than the selected following gap.
ACC can also be set while the vehicle is
stopped if ACC is on and the brake pedal is
applied.
The ACC indicator displays in the instrument
cluster and Head-Up Display (HUD),
if equipped. When the ACC is active, the
indicator turns green.
Be mindful of speed limits, surrounding
traffic speeds, and weather conditions when
selecting the set speed.
Resuming a Set Speed
If the ACC is set at a desired speed and then
the brakes are applied, the ACC is
disengaged without erasing the set speed
from memory.

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Driving and Operating 217
To begin using ACC again, press RES+ up
briefly.
.If the vehicle is moving more than 5 km/h
(3 mph), it returns to the previous set
speed.
.If the vehicle is stopped with the brake
pedal applied, press RES+ and release the
brake pedal. ACC will hold the vehicle
until RES+ or the accelerator pedal is
pressed.
A green ACC indicator and the set speed
display on the instrument cluster. The
vehicle ahead indicator may be flashing if a
vehicle ahead was present and moved. See
“Approaching and Following a Vehicle” later
in this section.
Once ACC has resumed, the vehicle speed
will increase to the set speed under the
following conditions:
.There is no vehicle ahead.
.The vehicle ahead is beyond the selected
following gap.
.The vehicle speed is not being limited
because of a sharp turn. Increasing Speed While ACC is at a Set Speed
If ACC is already activated, do one of the
following:
.Use the accelerator to get to the higher
speed. Briefly press and release SET–
and
release the accelerator pedal. The vehicle
will now cruise at the higher speed.
When the accelerator pedal is pressed,
ACC will not brake because it is
overridden. While overridden, the ACC
indicator will turn blue on the instrument
cluster and heads up display, if equipped.
.Press and hold RES+ up until the desired
set speed appears on the display, then
release it.
.To increase vehicle speed in small
increments, press RES+ up briefly. For
each press, the vehicle goes 1 km/h or
(1 mph) faster.
.To increase vehicle speed in larger
increments, hold RES+. While holding
RES+, the vehicle speed increases to the
next 5 km/h (5 mph) step, then continues
to increase by 5 km/h (5 mph) at a time.
The set speed can also be increased while
the vehicle is stopped.
.If stopped with the brake applied, press
RES+ until the desired set speed is
displayed.
.If ACC is holding the vehicle at a stop and
there is another vehicle directly ahead,
pressing RES+ will increase the set speed.
.Pressing RES+ when there is no longer a
vehicle ahead or the vehicle ahead is
pulling away and the brake is not applied
will cause the ACC to resume.
When it is determined that there is no
vehicle ahead inside 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. Press SET– down and release the
accelerator pedal. The vehicle will now
cruise at the lower speed.
.Press and hold SET– down until the
desired lower speed is reached, then
release it.
.To decrease the vehicle speed in smaller
increments, press SET− down briefly. For
each press, the vehicle goes about 1 km/h
or (1 mph) slower.

Buick E2UB-N Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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218 Driving and Operating
.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
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
3on 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 and HUD (if equipped). 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 0231.
Alerting the Driver
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, the collision
alert symbol 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” underVehicle Personalization
0 109.
See Defensive Driving 0188.
Approaching and Following a Vehicle
The vehicle ahead indicator is in the
instrument cluster and HUD display (if
equipped).
The vehicle ahead indicator only displays
when a vehicle is detected in your vehicle’s
path moving in the same direction.
If this indicator is not displaying, ACC will
not respond to or brake to vehicles ahead.
ACC automatically slows the vehicle down
and adjusts vehicle speed to follow the
vehicle in front at the selected follow gap.
The vehicle speed increases or decreases to
follow the vehicle in front of you, but will
not exceed the set speed. It may apply
limited braking, if necessary. When braking
is active, the brake lamps will come on. The

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automatic braking may feel or sound
different than if the brakes were applied
manually. This is normal.
Passing a Vehicle While Using ACC
If the set speed is high enough, and the left
turn signal is used to pass a vehicle ahead
in the selected following gap, ACC may
assist by gradually accelerating the vehicle
prior to the lane change.
{Warning
When using ACC to pass a vehicle or
perform a lane change, the following
distance to the vehicle being passed may
be reduced. ACC may not apply sufficient
acceleration or braking when passing a
vehicle or performing a lane change.
Always be ready to manually accelerate
or brake to complete the pass or lane
change.
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 (Continued)
Warning (Continued)
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.
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” 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 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

Buick E2UB-N Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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220 Driving and Operating
Cruise Go Notifier”in“Collision/Detection
Systems” underVehicle Personalization
0 109.
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 Electric
Parking Brake status light will turn on. See
Electric Parking Brake 0208. To release the
EPB, press the accelerator pedal.
A DIC warning message may display
indicating to shift to P (Park) before exiting
the vehicle.
{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 and in the HUD,
if equipped, to indicate that automatic
braking will not occur. ACC will resume
operation when the accelerator pedal is not
being pressed.
{Warning
The ACC will not automatically apply the
brakes if your foot is resting on the
accelerator pedal. You could crash into a
vehicle ahead of you. Curves in the Road
{Warning
On curves, ACC may not detect a vehicle
ahead in your lane. You could be startled
if the vehicle accelerates up to the set
speed, especially when following a vehicle
exiting or entering exit ramps. You could
lose control of the vehicle or crash. Do
not use ACC while driving on an entrance
or exit ramp. Always be ready to use the
brakes if necessary.
{Warning
On curves, ACC may respond to a vehicle
in another lane, or may not have time to
react to a vehicle in your lane. You could
crash into a vehicle ahead of you, or lose
control of your vehicle. Give extra
attention in curves and be ready to use
the brakes if necessary. Select an
appropriate speed while driving in curves.
ACC may operate differently in a sharp
curve. It may reduce the vehicle speed if the
curve is too sharp. ACC automatically slows

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Driving and Operating 221
the vehicle down while navigating the curve
and may increase speed out of the curve,
but will not exceed the set speed.
When following a vehicle and entering a
curve, ACC may not detect the vehicle ahead
and accelerate to the set speed. When this
happens the vehicle ahead indicator will not
appear.
ACC may detect a vehicle that is not in your
lane and apply the brakes.ACC may occasionally provide an alert and/
or braking that is considered unnecessary.
It could respond to vehicles in different
lanes, signs, guardrails, and other stationary
objects when entering or exiting a curve.
This is normal operation. The vehicle does
not need service.
Other Vehicle Lane Changes
ACC will not detect a vehicle ahead until it
is completely in the lane. The brake 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. The driver will often need to take over
acceleration and braking on steep hills,
especially when towing a trailer. If the
brakes are applied, the ACC disengages.
Disengaging ACC
There are three ways to disengage ACC:
.Step lightly on the brake pedal.
.Press*.
.Press].

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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 0109.
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 0109.
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.
.Front and rear bumpers and the area
below the bumpers
.Front grille and headlamps
.Front camera lens in the front grille or
near the front emblem
.Front side and rear side panels
.Outside of the windshield in front of the
rearview mirror
.Side camera lens on the bottom of the
outside mirrors
.Rear side corner bumpers
.Rear Vision Camera above the license
plate
Assistance Systems for Parking or
Backing
If equipped, the Rear Vision Camera (RVC),
Rear Park Assist (RPA), Front Park Assist
(FPA), Surround Vision, Reverse Automatic
Braking (RAB) and Backing Warning System,
Rear Cross Traffic Alert (RCTA), and
Automatic Parking Assist (APA) may help the
driver park or avoid objects. Always check
around the vehicle when parking or backing.
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 Home or Back on the

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Driving and Operating 227
.The sensors may not be clean. Keep the
vehicle's front and rear bumpers free of
mud, dirt, snow, ice, and slush. For
cleaning instructions, seeExterior Care
0 305.
.The Park Assist sensors may be covered
by frost or ice. Frost or ice can form
around and behind the sensors and may
not always be seen; this can occur after
washing the vehicle in cold weather. The
message may not clear until the frost or
ice has melted.
If a service message displays and the above
conditions do not exist, take the vehicle to
your dealer for repairs.
If the Park Assist System does not activate
due to a temporary condition, a system off
message is shown on the display. This can
occur under the following conditions:
.The driver has disabled the system.
.An object is currently blocking the rear
sensors (for example, bike rack, tailgate,
trailer hitch, etc.). Once the object is
removed, Park Assist will return to normal
operation.
.The bumper is damaged. Take the vehicle
to your dealer for repairs.
.Other conditions, such as vibrations from
a jackhammer or the compression of air
brakes on a very large truck, are affecting
system performance.
Backing Warning and Reverse Automatic
Braking (RAB)
Vehicles with Adaptive Cruise Control (ACC)
have the Backing Warning System and
Reverse Automatic Braking (RAB) system.
When in R (Reverse), Backing Warning alerts
of rear objects at vehicle speeds greater
than 8 km/h (5 mph), and RAB may
automatically brake hard at speeds between
1–32 km/h (0.5–20 mph).
The Backing Warning System will beep once
from the rear when an object is first
detected, or pulse twice on both sides of the
Safety Alert Seat. When the system detects
a potential crash, beeps will be heard from
the rear, or five pulses will be felt on both
sides of the Safety Alert Seat. There may
also be a brief, sharp application of the
brakes.{Warning
The Backing Warning System only
operates at speeds greater than 8 km/h
(5 mph). It does not detect children,
pedestrians, bicyclists, animals, or objects
below the bumper or that are too close
or too far from the vehicle. In some
situations, such as at higher backing
speeds, there may not be enough time
for the short, sharp application of the
vehicle brake system to occur. To prevent
injury, death, or vehicle damage, even
with the Backing Warning System, always
check the area around the vehicle and
check all mirrors before backing.
When the vehicle is in R (Reverse), if the
system detects the vehicle is backing too
fast to avoid a crash with a detected object
behind your vehicle in your path, it may
automatically brake hard to a stop to help
avoid or reduce the harm caused by a
backing crash.

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228 Driving and Operating
{Warning
RAB may not avoid many types of
backing crashes. Do not wait for the
automatic braking to apply. This system
is not designed to replace driver braking
and only works in R (Reverse) when an
object is detected directly behind the
vehicle. It may not brake or stop in time
to avoid a crash. It will not brake for
objects when the vehicle is moving at
very low speeds. It does not detect
children, pedestrians, bicyclists, animals,
or objects below the bumper or that are
too close or too far from the vehicle. To
prevent injury, death, or vehicle damage,
even with RAB, always check the area
around the vehicle before and while
backing.
Pressing the brake pedal after the vehicle
comes to a stop will release RAB. If the
brake pedal is not pressed soon after the
stop, the Electric Parking Brake (EPB) may be
set. When it is safe, press the accelerator
pedal firmly at any time to override RAB.
{Warning
There may be instances where
unexpected or undesired automatic
braking occurs. If this happens, either
press the brake pedal or firmly press the
accelerator pedal to release the brakes
from the RAB system. Before releasing
the brakes, check the RVC and check the
area around the vehicle to make sure it is
safe to proceed.
Rear Cross Traffic Alert (RCTA)
If equipped, RCTA displays a red warning
triangle with a left or right pointing arrow
on the infotainment display 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 left or
right or three Safety Alert Seat pulses occur
on the left or right side, depending on the
direction of the detected vehicle.
Use caution while backing up when towing
a trailer, as the RCTA detection zones that
extend out from the back of the vehicle do
not move further back when a trailer is
towed.
Enhanced Automatic Parking Assist (APA)
If equipped, under certain conditions
Enhanced Automatic Parking Assist (APA) can
use sensors based on sonar technology
along the vehicle’s front, rear and sides to
detect a parking spot and automatically park
the vehicle. The vehicle will automatically
maneuver into a detected spot moving at or
near idle speed. It does this by
automatically steering, braking, accelerating,
and gear shifting. The driver must always be
prepared to apply braking if necessary. A
display and beeps help to guide the parking
maneuvers.
{Warning
APA may not always detect objects in the
parking space, objects that are not rigid
(e.g. shrubs and chain-link fences), objects
below the bumper, objects high off the
ground (e.g. flatbed trucks), hanging
objects, objects below ground level such
(e.g. large potholes), or moving objects
(e.g. pedestrians, cyclists, vehicles).
Always verify that the parking space is
appropriate for parking a vehicle. APA
may not respond to changes in the (Continued)

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Warning (Continued)
parking space, such as movement of an
adjacent vehicle, or a person or object
entering the parking space. APA does not
detect or avoid traffic that is behind or
alongside of the vehicle. Always be
prepared to stop the vehicle during the
parking maneuver.
How to Activate Automatic Parking
To activate APA, press the soft-touch
button or hard switch
Ofor the system to
begin searching for a parking space while
driving forward at no greater than
30 km/h (18 mph). By default, APA searches
for parallel parking spaces to the right of
the vehicle up to the sensors’ range of 1.5 m
(5 ft). To search for a parking space to the
left, turn on the left turn signal or,
if available, change the side selection in the
infotainment display. To switch the parking
mode between parallel and perpendicular
press and hold
Owhile searching for a
valid parking spot or, if available, change the
parking mode in the infotainment display.
APA cannot park in all empty parking spots.
The parking spot must:
.Be sufficiently large to fit the vehicle
comfortably.
.Have an adjacent vehicle, wall, or pillar
for the system to align to.
After completely passing an eligible parking
spot, a beep sounds and a red stop symbol
is displayed in the driver information center.
Generally, APA selects the nearest empty
parking spot behind the vehicle, but under
some conditions may select a space that is
further back. Slow down and bring the
vehicle to a complete stop to begin.
Follow the displayed instructions. When
instructed to drive in reverse, shift to
R (Reverse) while holding the brakes. The
steering wheel will vibrate briefly as a
reminder to remove hands from the steering
wheel. Release the brakes slowly when the
vibration stops to begin automatic parking.
As the vehicle automatically steers, brakes, accelerates, and shifts gears into the parking
spot, check surroundings. Be prepared to
stop to avoid vehicles, pedestrians,
or objects.
A progress arrow displays the status of the
parking maneuver. Once automatic parking
is finished and the vehicle has come to a full
stop, FINAL POSITION - PRESS BRAKES
message will be displayed. Press and hold
the brakes, and APA will beep and display a
PARKING COMPLETE message. Shift the
vehicle to P (Park) and apply the parking
brake.
How to Activate Automatic Parallel Spot
Unparking Assist
To activate parallel spot unparking assist,
press the soft-touch button or hard switch
Oafter turning on the vehicle while
leaving it in P (Park) and the parking brake