wheel BUICK LACROSSE 2018 Service Manual

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
186 Driving and Operating
To enter Permanent Tap Shift Mode:1. With the transmission in D (Drive), pull back on the shift
lever to activate M (Manual
Mode). The M in the shift
pattern will illuminate in red,
and the D will switch to white.
2. Tap the left steering wheel control to downshift, and the
right control to upshift. To shift
to the lowest available gear,
press and hold the left control.
3. To exit, pull back on the shift lever a second time. The D in
the shift pattern will illuminate
in red, and the M will switch to
white.
To enter Temporary Tap Shift Mode: 1. With transmission in D, Tap the left steering wheel control to
downshift, and the right control
to upshift. 2. To shift to the lowest available
gear, press and hold the left
control.
3. To deactivate, hold the right upshift control briefly.
After temporary tap shifts, automatic
shifts return after no manual shifts
have been done for seven to
10 seconds.
While using Tap Shift, the vehicle
will have firmer, quicker shifting.
This can be used for sport driving or
when climbing or descending hills,
to stay in gear longer, or to
downshift for more power or engine
braking.
The transmission will only allow
shifting into gears appropriate for
the vehicle speed and engine
revolutions per minute (rpm). The
transmission will not automatically
shift to the next lower gear if the
engine rpm is too high, nor to the
next higher gear when the maximum
engine rpm is reached. If shifting is prevented for any
reason, a SHIFT DENIED message
will be displayed in the instrument
cluster.
When accelerating the vehicle from
a stop in snowy and icy conditions,
it is suggested to shift into second
gear. A higher gear allows the
vehicle to gain more traction on
slippery surfaces.

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
190 Driving and Operating
pressure to hold the vehicle
stationary. If AVH is holding the
vehicle, a Driver Information Center
(DIC) message displays. AVH will
not activate in a forward drive gear
when facing downhill, or in
R (Reverse) when facing uphill.
Select the duration of the AVH
feature through vehicle
personalization. See“Comfort and
Convenience” inVehicle
Personalization 0133. When Short
and Auto Park Brake Off is selected,
the vehicle is held stationary for up
to two seconds after the brake pedal
is released. When Long and Auto
Park Brake On 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 Short and Auto Park Brake Off 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 Long and Auto Park Brake
On is selected, it will hold the
vehicle for five minutes unless the
driver door is opened and the driver
seat belt is unbuckled prior to
releasing the brake pedal. When
deactivated after five minutes, or if it
is deactivated when the driver seat
belt is unlatched or the driver door is
opened, the Electric Parking Brake
will engage to prevent vehicle
movement.Ride Control Systems
Traction Control/
Electronic Stability
Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak®, an
electronic stability control system.
These systems help limit wheel slip
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any
of the drive wheels are spinning or
beginning to lose traction. When this
happens, TCS applies the brakes to
the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak selectively applies
braking pressure to any one of the

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 191
vehicle wheel brakes to assist the
driver in keeping the vehicle on the
intended path.
If cruise control is being used and
traction control or StabiliTrak begins
to limit wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road
conditions allow.
Both systems come on
automatically when the vehicle is
started and begins to move. The
systems may be heard or felt while
they are operating or while
performing diagnostic checks. This
is normal and does not mean there
is a problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary
to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow.
SeeIf the Vehicle Is Stuck 0166
and “Turning the Systems Off and
On” later in this section.
The indicator light for both systems
is in the instrument cluster. This
light will:
.
Flash when TCS is limiting
wheel spin.
. Flash when StabiliTrak is
activated.
. Turn on and stay on when either
system is not working.
If either system fails to turn on or to
activate, a message displays in the
Driver Information Center (DIC), and
dcomes on and stays on to
indicate that the system is inactive
and is not assisting the driver in
maintaining control. The vehicle is
safe to drive, but driving should be
adjusted accordingly. If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.
Drive the vehicle. If
dcomes on
and stays on, the vehicle may need
more time to diagnose the problem.
If the condition persists, see your
dealer.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
192 Driving and Operating
Turning the Systems Off
and On
Vehicle with Sport Mode Shown,Vehicle without Sport Mode Similar
Caution
Do not repeatedly brake or
accelerate heavily when TCS is
off. The vehicle driveline could be
damaged.
To turn off only TCS, press and
release
g. The traction off lighti
displays in the instrument cluster. To turn TCS on again, press and
release
g. The traction off lighti
displayed in the instrument cluster
will turn off.
If TCS is limiting wheel spin when
g
is pressed, the system will not turn
off until the wheels stop spinning.
To turn off both TCS and StabiliTrak,
press and hold
guntil the traction
off light
iand StabiliTrak OFF light
gcome on and stay on in the
instrument cluster.
To turn TCS and StabiliTrak on
again, press and release
g. The
traction off light
iand StabiliTrak
OFF light
gin the instrument cluster
turn off.
Adding accessories can affect the
vehicle performance. See
Accessories and Modifications
0 229.
Selective Ride Control
The vehicle may have Selective
Ride Control. The SPORT button is
on the center stack.
Selective Ride Control adapts to the
preference of the driver within one
of two driving modes:
TOUR : Default mode used for
normal and long-distance highway
driving. This setting provides a
smooth, soft ride.
SPORT : Use where road conditions
or personal preference demand
more control. This setting provides
responsive, controlled steering and

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 193
handling to road conditions through
increased steering effort and
suspension tuning. Press and
release SPORT and the light on the
button comes on. Press the button
again and the system returns to the
Tour Mode.
The setting can be changed at any
time. Based on road conditions,
steering wheel angle, and vehicle
speed, the system automatically
adjusts to provide the best handling
while providing a smooth ride. The
Tour and Sport Modes will feel
similar on a smooth road.
Selective Ride Control automatically
comes on in the Tour Mode when
the vehicle is started. When the
Sport Mode is turned off, the system
returns to the Tour Mode.Cruise Control
With cruise control the vehicle can
maintain a speed of about 40 km/h
(25 mph) or more without keeping
your foot on the accelerator. Cruise
control does not work at speeds
below 40 km/h (25 mph).
{Warning
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. Do not use
cruise control on winding roads or
in heavy traffic.
Cruise control can be dangerous
on slippery roads. On such roads,
fast changes in tire traction can
cause excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.
If equipped with the Traction Control
System (TCS), the system may
begin to limit wheel spin while you
are using cruise control. If this
happens, the cruise control will
automatically disengage. See Traction Control/Electronic Stability
Control
0190. If a collision alert
occurs when cruise control is
activated, cruise control is
disengaged. See Forward Collision
Alert (FCA) System 0208. When
road conditions allow you to safely
use it again, cruise control can be
turned back on.
Cruise control will disengage if
either TCS or StabiliTrak is
turned off.
If the brakes are applied, cruise
control disengages.

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
198 Driving and Operating
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 0208. 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 0133.
See Defensive Driving 0161.

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.