
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
198 Driving and Operating
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 0164.
Approaching and Following a
Vehicle
The vehicle ahead indicator is in the
instrument cluster and HUD display.
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 following 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 automatic
braking may feel or sound different
than if the brakes were applied
manually. This is normal.
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
vehicle it has never detected
moving. This can occur in
(Continued)
Warning (Continued)
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.
ACC Automatically Disengages
ACC may automatically disengage
and the driver will need to manually
apply the brakes to slow the
vehicle when:
. The sensors are blocked.
. The Traction Control System
(TCS) or electronic stability
control system has activated or
been disabled.
. No traffic or other objects are
being detected.
. There is a fault in the system.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
Driving and Operating 199
A message will appear on the DIC
indicating that cruise is disengaging.
The ACC active symbol will not be
displayed when ACC is no longer
active.
Notification to Resume ACC
ACC will maintain a following 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 “Go Notifier” in“Collision/
Detection Systems” underVehicle
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 safety 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 0187. To resume ACC and
release the EPB, press the
accelerator pedal.
A DIC warning message may
display indicating to shift to P (Park)
before exiting the vehicle. See
Vehicle Messages 0128.
{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. See Vehicle
Messages 0128. 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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
200 Driving and Operating
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(Continued)
Warning (Continued)
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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
Driving and Operating 201
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 TrailerDo 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 0286.
System operation may also be
limited under snow, heavy rain,
or road spray conditions.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
202 Driving and Operating
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
0 164.
(Continued)
Warning (Continued)
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.
. 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.
(Continued)
Warning (Continued)
.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 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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
Driving and Operating 205
Turning the Features On or Off
Use theXbutton on the center
stack to turn on or off the Front and
Rear Parking 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
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.
. Park exactly centered in a spot
that is marked too large.
. Always detect short curbs.
If the vehicle is equipped with
perpendicular parking mode, press
and hold
Oduring the search
process to switch the APA parking
mode between perpendicular and
parallel parking.
APA searches for parking spaces to
the right of the vehicle. To search for
a parking space to the left, turn on
the left turn signal.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
206 Driving and Operating
After completely passing a large
enough space bordered by two
vehicles or other objects, an audible
beep occurs and a red symbol
displays in the DIC.
APA will instruct the vehicle to stop
once a large enough space is found.
Follow the instructions in the DIC.
When instructed to drive in reverse,
shift to R (Reverse) to engage
automatic steering. The steeringwheel will briefly vibrate as a
reminder to remove hands from the
steering wheel. Check surroundings
and continue braking or accelerating
as needed, and be prepared to stop
to avoid vehicles, pedestrians,
or objects.
If the vehicle is in R (Reverse), but
does not steer into the expected
space, this may be because the
system is maneuvering the vehicle
into a previously detected space.
The APA system does not need
service.
If the vehicle exceeds 10 km/h
(6 mph), APA is automatically
disengaged and automatic steering
will turn off. A DIC progress arrow
displays the status of the parking
maneuver. Depending on the space
size, additional maneuvers may be
required, and there will be additional
instructions. When changing gears,
allow the automatic steering to
complete before continuing the
parking maneuver. Upon successful
completion of a maneuver, APA will
beep and display a PARKING
COMPLETE message. Place the
vehicle in P (Park).APA may automatically disengage if:
.
The steering wheel is used by
the driver.
. The maximum allowed speed is
exceeded.
. 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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-9803782) -
2017 - crc - 9/7/16
Driving and Operating 207
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 Control0194.
{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
(Continued)
Warning (Continued)
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 objects. Be ready to take
action and apply the brakes. See
Defensive Driving0164.
FCA can be disabled through
vehicle personalization. See
“Collision/Detection Systems” under
Vehicle 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;
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.