wheel BUICK LACROSSE 2015 Service Manual

Black plate (28,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-28 Driving and Operating
To rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission, seeIf
the Vehicle Is Stuck on page 9-9.
N (Neutral): In this position, the
engine does not connect with the
wheels. To restart the engine when
the vehicle is already moving, use
N (Neutral) only. Also, use
N (Neutral) when the vehicle is
being towed.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift
into a drive gear while the engine
is running at high speed.
{Caution
Shifting out of P (Park) or
N (Neutral) with the engine
running at high speed may
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Be sure the
engine is not running at high
speed when shifting the vehicle.
D (Drive): This position is for
normal driving. It provides good fuel
economy when pushing the
accelerator pedal around a quarter
of the way down. If more power is
needed for passing, press the
accelerator pedal over half, or all
the way down.
{Caution
If the vehicle accelerates slowly,
or does not shift gears, the
transmission could be damaged.
Have the vehicle serviced
right away.
M (Manual Mode) or M/S (Manual
Mode/Sport Mode): This position
allows the driver to select the gears
appropriate for current driving
conditions, and to activate Selective
Ride Control (if equipped). See
Manual Mode on page 9-29 and
Selective Ride Control on
page 9-36.

Black plate (30,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-30 Driving and Operating
engine rpm is too high, nor to the
next higher gear when the maximum
engine rpm is reached.
While in Manual Mode, the
transmission will automatically
downshift when the vehicle comes
to a stop. This will allow for more
power during take-off.
When accelerating the vehicle from
a stop in snowy and icy conditions,
you may want to shift into
2 (Second) gear. A higher gear
allows the vehicle to gain more
traction on slippery surfaces.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 on
page 10-77.
Brakes
Antilock Brake
System (ABS)
This vehicle has 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
might be heard while this test is
going on, and it might 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
on page 5-20.

Black plate (31,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-31
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 vehiclesuddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You may hear the ABS
pump or motor operating and feel
the brake pedal pulsate. This is
normal.
Braking in Emergencies
ABS allows you to steer and brake
at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Parking Brake
The Electric Parking Brake (EPB)
switch is on the center console. The
EPB can always be activated, even
if the ignition is off. To prevent
draining the battery, avoid repeated
cycles of the EPB when the engine
is not running.
The system has a red parking brake
status light and an amber parking
brake warning light. See
Electric
Parking Brake Light on page 5-20
and Service Electric Parking Brake
Light on page 5-20. There are also

Black plate (32,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-32 Driving and Operating
parking brake-related Driver
Information Center (DIC) messages.
SeeBrake System Messages on
page 5-36. In case of insufficient
electrical power, the EPB cannot be
applied or released.
Before leaving the vehicle, check
the red parking brake status light to
ensure that the parking brake is
applied.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Lift up the EPB switch momentarily.
The red parking brake status light
will flash and then stay on once the
EPB is fully applied. If the red
parking brake status light flashes
continuously, then the EPB is only
partially applied or there is a
problem with the EPB. A DIC
message will display. Release the
EPB and try to apply it again. If the
light does not come on, or keeps flashing, have the vehicle serviced.
Do not drive the vehicle if the red
parking brake status light is flashing.
See your dealer. See
Electric
Parking Brake Light on page 5-20.
If the amber parking brake warning
light is on, lift up on the EPB switch
and hold it up. Continue to hold the
switch until the red parking brake
status light remains on. If the amber
parking brake warning light is on,
see your dealer.
If the EPB is applied while the
vehicle is moving, the vehicle will
decelerate as long as the switch is
held up. If the switch is held up until
the vehicle comes to a stop, the
EPB will remain applied.
The vehicle may automatically apply
the EPB in some situations when
the vehicle is not moving. This is
normal, and is done to periodically
check the correct operation of the
EPB system.
If the EPB fails to apply, the rear
wheels should be blocked to
prevent vehicle movement.
EPB Release
To release the EPB:
1. Place the ignition in the ACC/ ACCESSORY or ON/RUN
position.
2. Apply and hold the brake pedal.
3. Push down momentarily on the EPB switch.
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
pushing down on the EPB switch
and holding it down. 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 (Continued)

Black plate (34,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-34 Driving and Operating
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 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.
See
If the Vehicle Is Stuck on
page 9-9 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.

Black plate (35,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-35
Ifdcomes 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.
Turning the Systems Off
and On
The TCS/StabiliTrak button is on the
center console.
{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 the
gbutton. The traction
off light
idisplays in the instrument
cluster. The appropriate DIC
message displays. See Ride Control
System Messages on page 5-42.
To turn TCS on again, press and
release the
gbutton. The traction
off light
idisplayed in the
instrument cluster will turn off.
If TCS is limiting wheel spin when
the
gbutton is pressed, the system
will not turn off until the wheels stop
spinning.
To turn off both TCS and StabiliTrak,
press and hold the
gbutton until
the traction off light
iand
StabiliTrak OFF light
gcome on
and stay on in the instrument
cluster. The appropriate DIC
message displays. See Ride Control
System Messages on page 5-42.

Black plate (36,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-36 Driving and Operating
To turn TCS and StabiliTrak on
again, press and release the
g
button. The traction off lightiand
StabiliTrak OFF light
gin the
instrument cluster turn off.
Adding accessories can affect the
vehicle performance. See
Accessories and Modifications on
page 10-3.
Limited-Slip Differential
Vehicles with a limited-slip
differential can give more traction on
snow, mud, ice, sand, or gravel.
It works like a standard differential
most of the time, but when traction
is low, this feature allows the drive
wheel with the most traction to
move the vehicle.
Selective Ride Control
The vehicle may have a ride control
system called Selective Ride
Control. The system provides the
following performance benefits:
.Reduced Impact Harshness
.Improved Road Isolation
.Improved High-Speed Stability
.Improved Handling Response
.Better Control of Body Ride
Motions
To switch from TOUR to SPORT
mode, move the shift lever to the
M/S (Manual/Sport) position. TOUR:
Use for normal city and
highway driving. This setting
provides a smooth, soft ride.
SPORT: Use where road conditions
or personal preference demand
more control. This setting provides
more “feel,” or response to road
conditions through increased
steering effort and suspension
tuning.
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.

Black plate (37,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-37
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 on page 9-34. If a collision
alert occurs when cruise control is
activated, cruise control is
disengaged. See
Forward Collision
Alert (FCA) System on page 9-50.
When road conditions allow you to
safely use it again, cruise control
can be turned back on.
If the brakes are applied, cruise
control disengages.
5(On/Off): Press to turn cruise
control on or off. A white indicator
comes on in the instrument cluster.
RES+ (Resume/Accelerate): If
there is a set speed in memory,
press the control up briefly to
resume to that speed or press and
hold to accelerate. If cruise control
is already active, use to increase
vehicle speed.

Black plate (38,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-38 Driving and Operating
SET−(Set/Coast): Press the
control down briefly to set the speed
and activate cruise control. If cruise
control is already active, use to
decrease vehicle speed.
*(Cancel): Press to disengage
cruise control without erasing the
set speed from memory.
Setting Cruise Control
If the
5button is on when not in
use, SET− or RES+ could get
pressed and go into cruise when not
desired. Keep the
5button off
when cruise is not being used.
1. Press the
5button to turn the
cruise system on.
2. Get to the speed desired.
3. Press and release the SET− control on the steering wheel.
The desired set speed briefly
appears in the instrument
cluster.
4. Take your foot off the accelerator pedal. The cruise control indicator on the
instrument cluster turns green after
the cruise control has been set to
the desired speed. See
Instrument
Cluster on page 5-8.
Resuming a Set Speed
If the cruise control is set at a
desired speed and then the brakes
are applied or
*is pressed, the
cruise control is disengaged without
erasing the set speed from memory.
Once the vehicle reaches about
40 km/h (25 mph) or more, press
RES+ up briefly. The vehicle returns
to the previously set speed.
Increasing Speed While Using
Cruise Control
If the cruise control system is
already activated:
.Press and hold RES+ up until
the vehicle accelerates to the
desired speed, then release it.
.To increase vehicle speed in
small increments, press RES+
up briefly. For each press, the
vehicle goes about 1.6 km/h
(1 mph) faster.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster on
page 5-8. The increment value used
depends on the units displayed.
Reducing Speed While Using
Cruise Control
If the cruise control system is
already activated:
.Press and hold SET− down until
the desired lower speed is
reached, then release it.
.To slow down in small
increments, press SET−down
briefly. For each press, the
vehicle goes about 1.6 km/h
(1 mph) slower.

Black plate (40,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-40 Driving and Operating
{Warning
ACC has limited braking ability
and may not have time to slow
the vehicle down enough to avoid
a collision with another vehicle
you are following. This can occur
when vehicles suddenly slow or
stop ahead, or enter your lane.
Also see“Alerting the Driver” in
this section. Complete attention is
always required while driving and
you should be ready to take
action and apply the brakes. See
Defensive Driving on page 9-3.
{Warning
Adaptive Cruise Control will not
detect or brake for children,
pedestrians, animals, or other
objects.
(Continued)
Warning (Continued)
Do not use Adaptive Cruise
Control 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.
Adaptive Cruise Control
performance is limited under
these conditions.
.On slippery roads where fast
changes in tire traction can
cause excessive wheel slip.
](On/Off):Press to turn the
system on or off. The indicator turns
white on the instrument cluster
when ACC is turned on.
RES+ (Resume/Accelerate):
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 active, use to increase
vehicle speed.