2015 BUICK LACROSSE light

Black plate (43,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-43
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. SeeForward
Collision Alert (FCA) System on
page 9-50.
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 on
page 5-45.
See Defensive Driving on page 9-3.
Approaching and Following a
Vehicle
The vehicle ahead symbol is in the
instrument cluster and HUD display.
The vehicle ahead symbol only
displays when a vehicle is detected
in your vehicle’s path moving in the
same direction.
If this symbol 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
lights 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
Adaptive Cruise Control (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
stop-and-go traffic or when a
vehicle suddenly appears due to
a vehicle ahead changing lanes.
Your vehicle may not stop and
(Continued)

Black plate (44,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-44 Driving and Operating
Warning (Continued)
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.
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 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 symbol
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” under
Vehicle Personalization on
page 5-45.
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, the ACC automatically applies the electric parking brake to
hold the vehicle. The electric
parking brake status light will turn
on. See
Parking Brake on
page 9-31. To resume ACC and
release the electric parking brake,
press the accelerator pedal.
A DIC warning message may
display indicating to shift to P (Park)
before exiting the vehicle. See
Vehicle Messages on page 5-35.
{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.

Black plate (47,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-47
Disengaging ACC
There are three ways to
disengage ACC:
.Step lightly on the brake pedal.
.Press*.
.Press].
Erasing Speed Memory
The cruise control set speed is
erased from memory if
]is
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 on page 10-85.
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
on page 9-3.
Under many conditions, these
systems will not:
(Continued)
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.
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.

Black plate (50,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-50 Driving and Operating
The vehicle may have instrument
cluster parking assist display with
bars that show“distance to object”
and object location information for
RPA. As the object gets closer,
more bars light up and the bars
change color from yellow to amber
to red.
When an object is first detected,
one beep will be heard from the
rear, or both sides of the Safety
Alert Seat will pulse two times.
When an object is very close
(<0.6 m (2 ft)), five beeps will sound,
or both sides of the Safety Alert
Seat will pulse five times.
Turning the Features On or Off
TheXbutton on the center stack
is used to turn on or off the Rear
Parking Assist. The indicator light
next to the button comes on when
the feature is on and turns off when
the feature has been disabled.
Turn off parking assist when towing
a trailer.
The parking assist symbols and
guidance lines can be turned on or
off through the Settings menu on
the infotainment system:
1. On the infotainment system, press the Settings screen
button, or turn the MENU knob
to highlight Settings and
press MENU.
2. Select Rear Camera. 3. Press Rear Park Assist Symbols
or Guidance Lines, and then
select OFF or ON.
Assistance Systems for
Driving
If equipped, when driving the
vehicle forward, Forward Collision
Alert (FCA), Lane Departure
Warning (LDW), Side Blind Zone
Alert (SBZA), Lane Change Alert
(LCA), and/or the Active Emergency
Braking System 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.

Black plate (54,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-54 Driving and Operating
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.
Brake Preparation
When quickly approaching a vehicle
ahead, Brake Preparation reduces
brake response time by having the
brake system prepared for driver
braking to occur more rapidly.
Automatic Braking
If ACP detects it is about to crash
with the vehicle you are following
that is moving or has come to a
stop, and the brakes have not been
applied, it may automatically brake
hard. This can help to reduce crash
damage and it may even help to
avoid some very low speed crashes. Automatic Braking 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 Automatic Braking.
{Warning
Automatic Braking 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 Automatic Braking, firmly
press the accelerator pedal, if it is
safe to do so.
Automatic Braking can be disabled
or reduced through vehicle
personalization. See the “Auto
Collision Preparation” portion of
“Collision/Detection Systems” under
Vehicle Personalization on
page 5-45.
{Warning
Using the Automatic Collision
Preparation System while towing
a trailer could cause you to lose
control of the vehicle and crash.
Turn the system off when towing
a trailer.
Side Blind Zone
Alert (SBZA)
If equipped, the SBZA system is a
lane-changing aid that assists
drivers with avoiding crashes that
occur with vehicles in the side blind
zone (or spot) areas. When the
vehicle is moving forward, the left or
right side mirror display will light up
if a 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

Black plate (55,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-55
the Lane Change Alert system, read
the entire Lane Change Alert
section before using this feature.
Lane Change Alert
If equipped, the Lane Change Alert
(LCA) system is a lane-changing aid
that assists drivers with avoiding
lane change crashes that occur with
vehicles in the side blind zone (or
spot) areas or with vehicles rapidly
approaching these areas from
behind. The LCA warning display
will light up in the corresponding
outside side mirror and will flash if
the turn signal is on.
{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(Continued)
Warning (Continued)
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.
1. SBZA Detection Zone
2. LCA Detection Zone
LCA Detection Zones
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. The
Side Blind Zone Alert (SBZA)
warning area starts at approximately
the middle of the vehicle and goes
back 5 m (16 ft). Drivers are also
warned of vehicles rapidly
approaching from up to 70 m (230 ft)
behind the vehicle.
How the System Works
The LCA symbol lights up in the
side mirrors when the system
detects a vehicle in the next lane
over that is in the side blind zone or
rapidly approaching from behind.
A lit LCA symbol indicates it may be
unsafe to change lanes. Before
making a lane change, check the
LCA display, check mirrors, glance
over your shoulder, and use the turn
signals.

Black plate (56,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-56 Driving and Operating
Left Side MirrorDisplayRight Side Mirror Display
When the vehicle is started, both
outside mirror LCA displays will
briefly come on to indicate the
system is operating. When the
vehicle is moving forward, the left or
right side mirror display will light up
if a vehicle is detected in the next
lane over in that blind zone or
rapidly approaching that 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 can be disabled through
vehicle personalization using the
Side Blind Zone Alert option. See
“Collision/Detection Systems” under
Vehicle Personalization on page 5-45. If LCA is disabled by the
driver, the LCA mirror displays will
not light up.
When the System Does Not
Seem to Work Properly
The LCA system requires some
driving for the system to calibrate to
maximum performance. This
calibration may occur more quickly if
the vehicle is driving on a straight
highway road with traffic and
roadside objects (e.g., guardrails,
barriers).
LCA displays may not come on
when passing a vehicle quickly or
when towing a trailer. The LCA
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
may alert to objects attached to the
vehicle, such as a trailer, bicycle,
or object extending out to either side
of the vehicle. Attached objects may
also interfere with the detection ofvehicles. This is normal system
operation; the vehicle does not need
service.
LCA may not always alert the driver
to vehicles in the next lane over,
especially in wet conditions or when
driving on sharp curves. 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 may not operate when the LCA
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 Care on
page 10-85. If the DIC still displays
the system unavailable message
after cleaning both sides of the
vehicle toward the rear corners of
the vehicle, see your dealer.

Black plate (57,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-57
If the LCA displays do not light up
when vehicles are in the side blind
zone or rapidly approaching this
zone and the system is clean, the
system may need service. Take the
vehicle to your dealer.
When LCA is disabled for any
reason other than the driver turning
it off, the Side Blind Zone Alert On
option will not be available on the
personalization menu.
Radio Frequency Information
SeeRadio Frequency Statement on
page 13-12.
Lane Departure
Warning (LDW)
If equipped, LDW may help avoid
crashes due to unintentional lane
departures. It may provide an alert if
the vehicle is crossing a lane
without using a turn signal in that
direction. LDW uses a camera
sensor to detect the lane markings
at speeds of 56 km/h (35 mph) or
greater.
{Warning
The LDW system does not steer
the vehicle. The LDW system
may not:
.Provide enough time to avoid
a crash.
.Detect lane markings under
poor weather or visibility
conditions. This can occur if
the windshield or headlamps
are blocked by dirt, snow,
or ice; if they are not in
proper condition; or if the sun
shines directly into the
camera.
.Detect road edges.
.Detect lanes on winding or
hilly roads.
If LDW only detects lane
markings on one side of the road,
it will only warn you when
departing the lane on the side
where it has detected a lane (Continued)
Warning (Continued)
marking. Always keep your
attention on the road and
maintain proper vehicle position
within the lane, or vehicle
damage, injury, or death could
occur. Always keep the
windshield, headlamps, and
camera sensors clean and in
good repair. Do not use LDW in
bad weather conditions.
How the System Works
The LDW camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LDW on and off, press
@on
the center stack. The control
indicator will light when LDW is on.