brake light BUICK LACROSSE 2015 Owner's Guide

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 (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 (1,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . 10-11
Engine Oil Life System . . . . . 10-13
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-15
Engine Air Cleaner/Filter . . . . 10-15
Cooling System . . . . . . . . . . . . 10-17
Engine Coolant . . . . . . . . . . . . . 10-19
Engine Overheating . . . . . . . . 10-21
Overheated Engine Protection
Operating Mode . . . . . . . . . . . 10-23 Power Steering Fluid (2.4L
L4 Engine and 3.6L
V6 Engine with FWD) . . . . . 10-23
Power Steering Fluid (3.6L V6 Engine with AWD) . . . . . 10-23
Washer Fluid . . . . . . . . . . . . . . . 10-24
Brakes . . . . . . . . . . . . . . . . . . . . . 10-25
Brake Fluid . . . . . . . . . . . . . . . . . 10-26
Battery . . . . . . . . . . . . . . . . . . . . . 10-27
All-Wheel Drive . . . . . . . . . . . . . 10-28
Starter Switch Check . . . . . . . 10-28
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-29
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-29
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-29
Wiper Blade Replacement . . . . . . . . . . . . . . 10-30
Windshield Replacement . . . 10-30
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-31
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-31
Halogen Bulbs . . . . . . . . . . . . . . 10-31 High Intensity Discharge
(HID) Lighting . . . . . . . . . . . . . 10-31
LED Lighting . . . . . . . . . . . . . . . 10-31
Headlamps, Front Turn Signal and Parking
Lamps . . . . . . . . . . . . . . . . . . . . 10-32
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-33
License Plate Lamp . . . . . . . . 10-33
Replacement Bulbs . . . . . . . . . 10-34
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . 10-34
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-35
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-35
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-36
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-40
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-42
All-Season Tires . . . . . . . . . . . . 10-43
Winter Tires . . . . . . . . . . . . . . . . 10-43
Summer Tires . . . . . . . . . . . . . . 10-43

Black plate (25,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-25
{Caution
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
to freeze and damage the
washer fluid tank and other
parts of the washer system.
.When using concentrated
washer fluid, follow the
manufacturer instructions for
adding water.
.Fill the washer fluid tank only
three-quarters full when it is
very cold. This allows for fluid
expansion if freezing occurs,
which could damage the tank
if it is completely full.
Brakes
Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or be
heard all the time when the vehicle
is moving, except when applying the
brake pedal firmly.
{Warning
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
{Caution
Continuing to drive with worn-out
brake pads could result in costly
brake repair.Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications. See
Capacities and
Specifications on page 12-2.
Brake pads should be replaced as
complete sets.
Brake Pedal Travel
See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service may be required.

Black plate (26,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
10-26 Vehicle Care
Replacing Brake System Parts
Always replace brake system parts
with new, approved replacement
parts. If this is not done, the brakes
may not work properly. The braking
performance expected can change
in many other ways if the wrong
replacement brake parts are
installed or parts are improperly
installed.
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid as
indicated on the reservoir cap. See
Engine Compartment Overview on
page 10-6for the location of the
reservoir. There are only two reasons why the
brake fluid level in the reservoir
might go down:
.The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake
hydraulic system can also cause
a low fluid level. Have the brake
hydraulic system fixed, since a
leak means that sooner or later
the brakes will not work well.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove brake fluid,
as necessary, only when work is
done on the brake hydraulic system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light on page 5-19.
What to Add
Use only new DOT 3 brake fluid
from a sealed container. See
Recommended Fluids and
Lubricants on page 11-12.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it. This
helps keep dirt from entering the
reservoir.

Black plate (38,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
10-38 Vehicle Care
Mini Fuses Usage14 Cabin Heater Coolant Pump
(eAssist)/Secondary
Air Injector/
Secondary Air
Injector with
Pressure Sensor
15 Motor Generator Unit Coolant Pump
(eAssist)
16 Run/Crank for eAssist Power
Inverter Module
17 Not Used
18 Sunshade Module, Vehicle Air
Purification System,
Ventilated Seats
20 Heated Steering Wheel (non eAssist) Mini Fuses Usage
23 Variable Effort Steering (if
equipped) or eAssist
Power Inverter
Module
29 Heated Seat, Left/ Power Lumbar
30 Heated Seat, Right/ Power Pack Cooling
Fan (eAssist)
31 All-Wheel Drive, Electronic
Suspension Control
32 Body Control Module 6
33 Memory Seat –
Front
34 Antilock Brake System Valves
35 Amplifier
36 Adaptive Forward Lighting (AFL)
Motors–Battery Mini Fuses Usage
37 Right High Beam
38 Left High Beam
46 Cooling Fan Relay
47 Six Cylinder Engine: Pre Catalytic
Converter Oxygen
Sensor Heater,
Canister Purge
Solenoid. Four
Cylinder Engine: Pre
and Post Catalytic
Converter Oxygen
Sensor Heaters,
Canister Purge
Solenoid
48 Fog Lamps
49 Right High Intensity Discharge
Headlamp
50 Left High Intensity Discharge
Headlamp
51 Horn

Black plate (58,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
10-58 Vehicle Care
The rubber in tires ages over time.
This also applies to the spare tire,
if the vehicle has one, even if it is
never used. Multiple factors
including temperatures, loading
conditions, and inflation pressure
maintenance affect how fast aging
takes place. GM recommends that
tires, including the spare if
equipped, be replaced after six
years, regardless of tread wear. The
tire manufacture date is the last four
digits of the DOT Tire Identification
Number (TIN) which is molded into
one side of the tire sidewall. The
first two digits represent the week
(01–52) and the last two digits, the
year. For example, the third week of
the year 2010 would have a
four-digit DOT date of 0310.
Vehicle Storage
Tires age when stored normally
mounted on a parked vehicle. Park
a vehicle that will be stored for at
least a month in a cool, dry, clean
area away from direct sunlight toslow aging. This area should be free
of grease, gasoline, or other
substances that can deteriorate
rubber.
Parking for an extended period can
cause flat spots on the tires that
may result in vibrations while
driving. When storing a vehicle for
at least a month, remove the tires or
raise the vehicle to reduce the
weight from the tires.
Buying New Tires
GM has developed and matched
specific tires for the vehicle. The
original equipment tires installed
were designed to meet General
Motors Tire Performance Criteria
Specification (TPC Spec)
system rating. When
replacement tires are needed,
GM strongly recommends
buying tires with the same TPC
Spec rating.
GM's exclusive TPC Spec
system considers over a dozen
critical specifications that impact
the overall performance of the
vehicle, including brake system
performance, ride and handling,
traction control, and tire
pressure monitoring
performance. GM's TPC Spec
number is molded onto the tire's
sidewall near the tire size. If the
tires have an all-season tread
design, the TPC Spec number
will be followed by MS for mud
and snow. See
Tire Sidewall
Labeling on page 10-44.
GM recommends replacing worn
tires in complete sets of four.
Uniform tread depth on all tires
will help to maintain the
performance of the vehicle.
Braking and handling
performance may be adversely
affected if all the tires are not
replaced at the same time.

Black plate (60,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
10-60 Vehicle Care
The Tire and Loading
Information label indicates the
original equipment tires on the
vehicle. SeeVehicle Load Limits
on page 9-10.
Different Size Tires and
Wheels
If wheels or tires are installed that
are a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, electronic stability control,
or All-Wheel Drive, the performance
of these systems can also be
affected.
{Warning
If different sized wheels are used,
there may not be an acceptable
level of performance and safety if
tires not recommended for those
wheels are selected. This
increases the chance of a crash
and serious injury. Only use GM
specific wheel and tire systems
developed for the vehicle, and
have them properly installed by a
GM certified technician.
See Buying New Tires on
page 10-58 andAccessories and
Modifications on page 10-3.
Uniform Tire Quality
Grading
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires by treadwear, traction, and
temperature performance. This
applies only to vehicles sold in
the United States. The grades
are molded on the sidewalls of
most passenger car tires. The
Uniform Tire Quality Grading
(UTQG) system does not apply
to deep tread, winter tires,
compact spare tires, tires with
nominal rim diameters of
10 to 12 inches (25 to 30 cm),
or to some limited-production
tires.
While the tires available on
General Motors passenger cars
and light trucks may vary with
respect to these grades, they
must also conform to federal
safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.