
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 187
Drive Systems
All-Wheel Drive
Vehicles with this feature always
send engine power to all four
wheels. It is fully automatic, and
adjusts itself as needed for road
conditions.
All-Wheel Drive (AWD) system
performance will be automatically
reduced when the compact spare
tire is in use. To restore full AWD
performance, and prevent excessive
wear to the AWD system, replace
the compact spare tire with a
full-size tire as soon as possible.
SeeCompact Spare Tire 0292.
Brakes
Antilock Brake
System (ABS)
This vehicle has an Antilock Brake
System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
When the vehicle begins to drive
away, ABS checks itself.
A momentary motor or clicking noise
may be heard while this test is going
on, and it may even be noticed that
the brake pedal moves a little. This
is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
0 120. If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses the wheels are
slowing down. If one of the wheels
is about to stop rolling, the computer
will separately work the brakes at
each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
you steer around the obstacle while
braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 189
normal, and is done to periodically
check the correct operation of the
EPB system.
If the EPB fails to apply, block the
rear wheels to prevent vehicle
movement.
EPB Release
To release the EPB:1. Turn the ignition on or to ACC/ ACCESSORY.
2. Apply and hold the brake pedal.
3. Press the EPB switch momentarily.
The EPB is released when the red
parking brake status light is off.
If the amber parking brake warning
light is on, release the EPB by
pressing and holding the EPB
switch. Continue to hold the switch
until the red parking brake status
light is off. If either light stays on
after release is attempted, see your
dealer.
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 under
conditions 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.
Automatic Vehicle
Hold (AVH)
The Automatic Vehicle Hold (AVH)
feature provides Hill Start Assist
(HSA). This 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, AVH uses braking

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
196 Driving and Operating
Warning (Continued)
always required while driving and
you should be ready to take
action and apply the brakes. See
Defensive Driving0161.
{Warning
ACC will not detect or brake for
children, pedestrians, animals,
or other objects.
Do not use ACC when:
. On winding and hilly roads
or when the sensors are
blocked by snow, ice, or dirt.
The system may not detect
a vehicle ahead. Keep the
entire front of the vehicle
clean.
. Visibility is low, such as in
fog, rain, or snow
conditions. ACC
performance is limited under
these conditions.
(Continued)
Warning (Continued)
.On slippery roads where
fast changes in tire traction
can cause excessive
wheel slip.
5:Press to turn the system on or
off. The indicator turns white on the
instrument cluster when ACC is
turned on.
RES+ : Press the control up briefly
to make the vehicle resume to a
previously set speed, or hold upwards to accelerate. If cruise
control is already engaged, use to
increase vehicle speed.
SET–
:Press the control down
briefly to set the speed and activate
cruise control. If cruise control is
already engaged, use to decrease
vehicle speed.
*: Press to disengage ACC
without erasing the selected set
speed.
[: 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 0110.
The increment value used depends
on the units displayed.
Setting Adaptive Cruise Control
If
5is on when not in use, it could
get pressed and go into ACC when
not desired. Keep
5off when
cruise is not being used.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 199
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 automaticbraking 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
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 if:
.
The sensors are blocked.
. The Traction Control System
(TCS) or electronic stability
control system has activated or
been disabled.
. There is a fault in the system.
. A possible false detection of
radar blockage occurs 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.
A message will appear on the DIC
indicating that cruise is disengaging.
The ACC indicator will turn white
when ACC is no longer active.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
202 Driving and Operating
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
Do not use ACC when driving on
steep hills or when towing a trailer.
ACC will not detect a vehicle in thelane 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 0300.
System operation may also be
limited under snow, heavy rain,
or road spray conditions.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 205
Warning (Continued)
only these camera(s). Always
check behind and around the
vehicle before driving. Failure to
use proper care may result in
injury, death, or vehicle damage.
Parking Assist
With RPA, and if equipped with FPA,
as the vehicle moves at speeds of
less than 8 km/h (5 mph) the
sensors on the bumpers may detect
objects up to 1.8 m (6 ft) behind the
vehicle and 1.2 m (4 ft) in front of the
vehicle within a zone 25 cm (10 in)
high off the ground and below
bumper level. These detection
distances may be shorter during
warmer or humid weather. Blocked
sensors will not detect objects and
can also cause false detections.
Keep the sensors clean of mud, dirt,
snow, ice, and slush; and clean
sensors after a car wash in freezing
temperatures.
{Warning
The Parking Assist system does
not detect children, pedestrians,
bicyclists, animals, or objects
located below the bumper or that
are too close or too far from the
vehicle. It is not available at
speeds greater than 8 km/h
(5 mph). To prevent injury, death,
or vehicle damage, even with
Parking Assist, always check the
area around the vehicle and
check all mirrors before moving
forward or backing.
The instrument cluster may have a
Parking Assist display with bars that
show “distance to object” and object
location information for RPA, and on
some vehicles, FPA. 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 in
the rear, one beep will be heard
from the rear. When an object is
very close (<0.6 m (2 ft) in the
vehicle rear, or <0.3 m (1 ft) in the
vehicle front), five beeps will sound
from the front or rear depending on
object location. Beeps for FPA are
higher pitched than for RPA.
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,

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 207
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-10999169) -
2018 - crc - 3/28/17
208 Driving and Operating
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 Control0195.
{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 Driving0161.
FCA can be disabled with either the
FCA steering wheel control or,
if equipped, through vehicle
personalization. See “Collision/
Detection Systems” underVehicle
Personalization 0133.
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
(Continued)