brake BUICK LACROSSE 2019 Workshop Manual

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
206 Driving and Operating
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” under
Vehicle Personalization 0138.
When the vehicle ahead drives
away, press RES+ or the
accelerator pedal to resume cruise
control. If stopped for more than
two minutes or if the driver door is
opened and the driver seat belt is
unbuckled, 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 0193. 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, a DIC warning
message will 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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Driving and Operating 207
{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.
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
brakes may need to be manually
applied.
Do Not Use ACC on Hills and
When Towing a Trailer

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
208 Driving and Operating
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
5.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
5is pressed
or if the ignition is turned off.
Cleaning the Sensing System
The radar sensor on the front of the
vehicle can become blocked by
snow, ice, dirt, or mud. This area
needs to be cleaned for ACC to
operate properly. For cleaning instructions, see
“Washing the Vehicle”
under
Exterior Care 0309.
System operation may also be
limited under snow, heavy rain,
or road spray conditions.
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. See Defensive Driving
0 166.
Under many conditions, these
systems will not: (Continued)

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Driving and Operating 209
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 0138.
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
0 138.
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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
212 Driving and Operating
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 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.
Turning the Features On or Off
Use theXbutton on the center
stack to turn on or off the Front and
Rear Park Assist and the Rear
Cross Traffic Alert (RCTA). The
indicator light in the button comes
on when the features are on and
turns off when the features have
been disabled. RCTA can also be turned off
through vehicle personalization. See
“Collision/Detection Systems”
under
Vehicle Personalization 0138.
Automatic Parking
Assist (APA)
If equipped, APA searches for and
steers the vehicle into parallel and
perpendicular parking spots. When
using APA, you must still shift gears,
and control the brakes and
accelerator. The Driver Information
Center (DIC) and audible beeps
help to guide parking maneuvers.
{Warning
APA does not apply the brakes.
APA may not detect objects in the
parking space, objects that are
soft or narrow, objects high off the
ground such as flatbed trucks,
or objects below ground level
such as large potholes. Always
verify that the parking space is
appropriate for parking a vehicle.
APA does not respond to changes
(Continued)
Warning (Continued)
in the 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.
Press
Oon the center stack to
enable the system to search for a
parking space that is large enough
and within 1.5 m (5 ft) of the vehicle.
The vehicle speed must be below
30 km/h (18 mph).
The system cannot:
. Detect whether it is a legal
parking space.
. Park exactly lined up with the
vehicle next to it if the spot is
approached at an angle or if the
parking space is angled.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
214 Driving and Operating
.There is a failure with the APA
system.
. Electronic Stability Control or
antilock brakes are activated.
. A high priority vehicle message
is displayed in the DIC.
To cancel APA, press
Oagain.
Assistance Systems for
Driving
If equipped, when driving the
vehicle in a forward gear, Forward
Collision Alert (FCA), Lane
Departure Warning (LDW), Lane
Keep Assist (LKA), Side Blind Zone
Alert (SBZA), Lane Change Alert
(LCA), and/or Forward Automatic
Braking (FAB) can help to avoid a
crash or reduce crash damage.
Forward Collision Alert
(FCA) System
The FCA system may help to avoid
or reduce the harm caused by
front-end crashes. FCA provides a
flashing red alert on the windshield, and beeps or pulses the Safety Alert
Seat when approaching a vehicle
directly ahead too quickly. FCA also
provides a 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). See
Adaptive Cruise Control
0201.
{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,
(Continued)
Warning (Continued)
bridges, construction barrels,
or other objects. Be ready to take
action and apply the brakes. See
Defensive Driving0166.
FCA can be disabled with either the
FCA steering wheel control or,
if equipped, through vehicle
personalization. See “Collision/
Detection Systems” underVehicle
Personalization 0138.
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;

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Driving and Operating 215
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 AlertWhen your vehicle approaches
another vehicle too rapidly, the red
collision alert symbol on the HUD
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.
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 AlertThe 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
alert timing. The first button press
shows the current setting on the
Driver Information Center (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

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
216 Driving and Operating
timing. The range of selectable alert
timing may not be appropriate for all
drivers and driving conditions.
Changing the FCA timing setting
automatically changes the following
gap setting (Far, Medium, or Near)
for the Adaptive Cruise Control
(ACC) feature.
Following Distance Indicator
The following distance to a moving
vehicle you are following is
indicated in following time in
seconds on the DIC. SeeDriver
Information Center (DIC) 0131. 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, cleaning the
outside of the windshield in front of
the camera sensor and the front of
the vehicle may correct the issue.
Forward Automatic
Braking (FAB)
If the vehicle has Adaptive Cruise
Control (ACC), it also has FAB,
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 moderately or
hard. This forward automatic
braking can only occur if a vehicle is
detected. This is shown by the FCA vehicle ahead indicator being lit.
See
Forward Collision Alert (FCA)
System 0214.
The system works when driving in a
forward gear between 10 km/h
(6 mph) and 180 km/h (112 mph) for
moving vehicles, or between
10 km/h (6 mph) and 55 km/h
(34 mph) for stationary vehicles.
It can detect vehicles up to
approximately 60 m (197 ft).
{Warning
FAB is an emergency crash
preparation feature and is not
designed to avoid crashes. Do
not rely on FAB to brake the
vehicle. FAB will not brake
outside of its operating speed
range and only responds to
detected vehicles.
FAB may not: . Detect a vehicle ahead on
winding or hilly roads.
(Continued)

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Driving and Operating 217
Warning (Continued)
.Detect all vehicles,
especially vehicles with a
trailer, tractors, muddy
vehicles, etc.
. Detect a vehicle when
weather limits visibility, such
as in fog, rain, or snow.
. Detect a vehicle ahead if it
is partially blocked by
pedestrians or other objects.
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.
FAB may slow the vehicle to a
complete stop to try to avoid a
potential crash. The vehicle will only
hold at a stop briefly. A firm press of
the accelerator pedal will also
release FAB.
{Warning
FAB may automatically brake the
vehicle suddenly in situations
where it is unexpected and
undesired. It could respond to a
turning vehicle ahead, guardrails,
signs, and other non-moving
objects. To override FAB, firmly
press the accelerator pedal, if it is
safe to do so.
Intelligent Brake Assist (IBA)
IBA may activate when the brake
pedal is applied quickly by providing
a boost to braking based on the
speed of approach and distance to
a vehicle ahead.
Minor brake pedal pulsations or
pedal movement during this time is
normal and the brake pedal should
continue to be applied as needed.
IBA will automatically disengage
only when the brake pedal is
released.
{Warning
IBA may increase vehicle braking
in situations when it may not be
necessary. You could block the
flow of traffic. If this occurs, take
your foot off the brake pedal and
then apply the brakes as needed.
FAB and IBA can be disabled
through vehicle personalization. See
Vehicle Personalization 0138.
{Warning
Using FAB or IBA while towing a
trailer could cause you to lose
control of the vehicle and crash.
Turn the system to 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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
218 Driving and Operating
.There is a problem with the
StabiliTrak/Electronic Stability
Control (ESC) system.
The FAB 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 directly
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 Forward
Automatic Braking (FAB) system
may also respond to pedestrians.
See Forward Automatic Braking
(FAB) 0216. 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.
. Due to poor visibility,
including nighttime
conditions, fog, rain,
or snow.
. If the FPB sensor is blocked
by dirt, snow, or ice.
(Continued)
Warning (Continued)
.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 0166.
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 0138.
Detecting the Pedestrian
Ahead