
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Climate Controls 161
To turn Auto Defog off or on, see
“Climate and Air Quality”under
Vehicle Personalization 0138.
Ionizer : If equipped with an ionizer,
this feature helps to clean the air
inside the vehicle and remove
contaminants such as pollen, odors,
and dust. If the climate control
system is on and the ionizer is
enabled, the ionizer status indicator
will be lit on the climate control
display. To turn the ionizer on or off,
see “Climate and Air Quality” under
Vehicle Personalization 0138.
Rear Window Defogger
K:Press to turn the rear window
defogger on or off. An indicator light
on the control comes on to show
that the rear window defogger is on.
The rear window defogger only
works when the engine is running.
It turns off when the ignition is
turned off or in ACC/ACCESSORY.
The rear window defogger can be
set to automatic operation. See
“Climate and Air Quality” under
Vehicle Personalization 0138.
When Auto Rear Defog is selected, the rear window defogger turns on
automatically when the interior
temperature is cold and the outside
temperature is about 4 °C (40 °F)
and below. The auto rear defogger
turns off automatically after about
10 minutes, or after five minutes if
the outside temperature is not
as cold.
For eAssist vehicles, auto rear
defog will only run during a remote
start and the feature is not available
in the Vehicle Personalization menu.
The upper gridlines on the rear
window are antenna lines and are
not intended to heat when the
defogger is activated.
The heated outside mirrors turn on
when the rear window defogger
control is on and help to clear fog or
frost from the surface of the mirror.
See
Heated Mirrors 046.
Caution
Do not try to clear frost or other
material from the inside of the
front windshield and rear window
with a razor blade or anything
else that is sharp. This may
damage the rear window
defogger grid and affect the
radio's ability to pick up stations
clearly. The repairs would not be
covered by the vehicle warranty.
Heated and Ventilated Seats
MorL:If equipped, pressMorLto heat the driver or passenger seat.
Cor{:If equipped, pressCor{to ventilate the driver or
passenger seat. See Heated and
Ventilated Front Seats 059.
Remote Start Climate Control
Operation : The climate control
system may run when the vehicle is
started remotely. If equipped with
heated or ventilated seats, they may
come on during a remote start.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Driving and Operating 195
Caution
Driving with the parking brake on
can overheat the brake system
and cause premature wear or
damage to brake system parts.
Make sure that the parking brake
is fully released and the brake
warning light is off before driving.
Automatic EPB Release
The EPB will automatically release if
the vehicle is running, placed into
gear, and an attempt is made to
drive away. Avoid rapid acceleration
when the EPB is applied, to
preserve parking brake lining life.
Brake Assist
The Brake Assist feature is
designed to assist the driver in
stopping or decreasing vehicle
speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake
control module to supplement the
power brake system underconditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle. The
stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time is
normal and the driver should
continue to apply the brake pedal as
the driving situation dictates. The
Brake Assist feature will
automatically disengage when the
brake pedal is released or brake
pedal pressure is quickly
decreased.
Hill Start Assist (HSA)
The Hill Start Assist (HSA) feature
will activate when the vehicle is
stopped on a moderate to steep
grade to help prevent it from rolling
in an unintended direction. After the
brake pedal has been released and
before the accelerator pedal has
been pressed, HSA uses braking
pressure to hold the vehiclestationary. If HSA is holding the
vehicle, a Driver Information Center
(DIC) message displays. HSA will
not activate in a forward drive gear
when facing downhill, or in
R (Reverse) when facing uphill.
Select the duration of the HSA
feature through vehicle
personalization. See
”Extended Hill
Start Assist” under“Comfort and
Convenience” inVehicle
Personalization 0138. When
Standard Hold is selected, the
vehicle is held stationary for up to
two seconds after the brake pedal is
released. When Extended Hold is
selected, the vehicle is held
stationary for up to five minutes
after the brake pedal is released. In
either case, override the hold
feature by pressing the accelerator
pedal and attempting to drive away.
If Standard Hold is selected, it will
hold the vehicle for two seconds
unless the driver door is opened or
the driver seat belt is unbuckled
after releasing the brake pedal.
If Extended Hold is selected, it will
hold the vehicle for five minutes

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
204 Driving and Operating
When it is determined that there is
no vehicle ahead or the vehicle
ahead is beyond the selected
following gap, then the vehicle
speed will increase to the set speed.
Reducing Speed While ACC is at a
Set Speed
Do one of the following:
.Use the brake to get to the
desired lower speed. Release
the brake and press SET–. 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 speed decreases to the
next 5 km/h (1 mph) mark on the
speedometer.
Selecting the Follow Distance Gap
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
[on 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. 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 0214.
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 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. See
“Collision/Detection Systems” under
Vehicle Personalization 0138.
See Defensive Driving 0166.

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 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 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.