engine BUICK LACROSSE 2012 Owner's Manual

Black plate (24,1)Buick LaCrosse Owner Manual - 2012
10-24 Vehicle Care
Brake Adjustment
Every time the brakes are applied,
with or without the vehicle moving,
the brakes adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is
complex. Its many parts have to be
of top quality and work well together
if the vehicle is to have really good
braking. The vehicle was designed
and tested with top-quality brake
parts. When parts of the braking
system are replaced, be sure to get
new, approved replacement parts.
If this is not done, the brakes might
not work properly. For example,
installing disc brake pads that are
wrong for the vehicle, can change
the balance between the front and
rear brakes—for the worse. The
braking performance expected can
change in many other ways if the
wrong replacement brake parts are
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 10‑6 for 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.

Black plate (25,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-25
When the brake fluid falls to a low
level, the brake warning light comes
on. SeeBrake System Warning
Light on page 5‑20.
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.
{WARNING
With the wrong kind of fluid in the
brake hydraulic system, the
brakes might not work well. This
could cause a crash. Always use
the proper brake fluid. Notice
.Using the wrong fluid can
badly damage brake
hydraulic system parts. For
example, just a few drops of
mineral-based oil, such as
engine oil, in the brake
hydraulic system can
damage brake hydraulic
system parts so badly that
they will have to be replaced.
Do not let someone put in
the wrong kind of fluid.
.If brake fluid is spilled on the
vehicle's painted surfaces,
the paint finish can be
damaged. Be careful not to
spill brake fluid on the
vehicle. If you do, wash it off
immediately.
Battery
This vehicle has a standard 12‐volt
battery. Refer to the replacement
number on the original battery label
when a new standard 12‐volt battery
is needed.
eAssist vehicles also have a high
voltage battery. Only a trained
service technician with the proper
knowledge and tools should inspect,
test, or replace the high voltage
battery. See your dealer if the high
voltage battery needs service. The
dealer has information on how to
recycle the high voltage battery.
There is also information available
at http://www.recyclemybattery.com.

Black plate (27,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-27
Starter Switch Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular brake.
See Parking Brake on
page 9‑36.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts. 3. Try to start the engine in each
gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control
Function Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface. 2. Firmly apply the parking brake.
See Parking Brake on
page 9‑36.
Be ready to apply the regular
brake immediately if the vehicle
begins to move.
3. With the engine off, turn the ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.

Black plate (28,1)Buick LaCrosse Owner Manual - 2012
10-28 Vehicle Care
Ignition Transmission
Lock Check
While parked, and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park).
.With the key access ignition
system, the ignition key should
come out only in LOCK/OFF.
SeeIgnition Positions (Key
Access) on page 9‑18 orIgnition
Positions (Keyless Access) on
page 9‑20.
Contact your dealer if service is
required.
Park Brake and P (Park)
Mechanism Check
{WARNING
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move. Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
.To check the P (Park)
mechanism's holding ability:
With the engine running, shift to
P (Park). Then release the
parking brake followed by the
regular brake.
Contact your dealer if service is
required.

Black plate (38,1)Buick LaCrosse Owner Manual - 2012
10-38 Vehicle Care
Fuses and Circuit
Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuit
breakers. This greatly reduces the
chance of damage caused by
electrical problems.
To check a fuse, look at the
silver-colored band inside the fuse.
If the band is broken or melted,
replace the fuse. Be sure to replace
a bad fuse with a new one of the
identical size and rating.Fuses of the same amperage can
be temporarily borrowed from
another fuse location, if a fuse goes
out. Replace the fuse as soon as
possible.
To identify and check fuses, circuit
breakers, and relays, see
Engine
Compartment Fuse Block on
page 10‑38, Instrument Panel Fuse
Block on page 10‑42, and Rear
Compartment Fuse Block on
page 10‑44.
Engine Compartment
Fuse Block
To remove the fuse block cover,
squeeze the three retaining clips on
the cover and lift it straight up.
Notice: Spilling liquid on any
electrical component on the
vehicle may damage it. Always
keep the covers on any electrical
component.

Black plate (39,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-39
Engine Compartment Fuse Block
The vehicle may not be equipped
with all of the fuses, relays, and
features shown. J-CaseFuses Usage
6 Wiper
12 Starter J-Case
Fuses Usage
21 Rear Power
Windows
22 Sunroof
24 Front Power
Windows J-Case
Fuses Usage
25 Passive Entry/
Passive Start
Module
—Battery 2
(eAssist)
26 Antilock Brake
System Pump
27 Electric Park Brake
28 Rear Window
Defogger
41 Brake
Vacuum Pump
42 Cooling Fan K2
43 Not Used
44 Transmission
Auxiliary Oil Pump
(eAssist)
45 Cooling Fan K1
59 AIR Pump

Black plate (40,1)Buick LaCrosse Owner Manual - 2012
10-40 Vehicle Care
Mini Fuses Usage1 Transmission
Control
Module
—Battery
2 Engine Control
Module Battery
3 Air Conditioning
Compressor Clutch
5 Engine Control
Module Run/Crank
8 Ignition
Coils
—Even (Six
Cylinder Engine),
Ignition Coils —All
(Four Cylinder
Engine
9 Ignition Coils
—Odd
(Six Cylinder
Engine)
10 Engine Control
Module
—Switched
Battery (from Engine
Control Module
Relay) Mini Fuses Usage
11 Six Cylinder Engine:
Post Catalytic
Converter Oxygen
Sensor Heater,
Mass Air Flow
Sensor, Flex Fuel
Sensor
13 Run/Crank for
Transmission
Control Module and
Fuel System Control
Module
14 Cabin Heater
Coolant Pump
(eAssist)
15 Motor Generator
Unit Coolant Pump
(eAssist)
16 Run/Crank for
eAssist Power
Inverter Module
17 Airbag
Module
—Run/
Crank Mini Fuses Usage
18 Vented Seats
(eAssist)
23 Variable Effort
Steering
(if equipped) or
eAssist Power
Inverter Module
29 Power Lumbar, Left
30 Power Lumbar,
Right or Power Pack
Cooling Fan
(eAssist)
31 Passive Entry/
Passive Start
Module
—Battery 1
(eAssist)
32 Body Control
Module 6
33 Heated
Seat
—Front
34 Antilock Brake
System Valves
35 Amplifier

Black plate (41,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-41
Mini Fuses Usage36 Adaptive Forward
Lighting (AFL)
Motors
—Battery
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, Mass Air
Flow Sensor.
48 Fog Lamps
49 Right High Intensity
Discharge
Headlamp Mini Fuses Usage
50 Left High Intensity
Discharge
Headlamp
51 Horn
52 Cluster Run/Crank
53 Run/Crank for Inside
Rearview Mirror,
Rear Vision Camera
54 Run/Crank for:
Heating, Ventilation
and Air Conditioning
55 Outside Rearview
Mirror, Universal
Garage Door
Opener, Front
Window Switches
56 Windshield Washer
60 Heated Mirror
62 Canister Vent
64 Adaptive Forward
Lighting (AFL)
Module
—Battery Mini Fuses Usage
65 Not Used
66 AIR Solenoid
(eAssist)
67 Fuel System Control
Module
69 Regulated Voltage
Control Sensor
70 Ultrasonic Parking
Assist/Side
Blind Zone
Mini Relays Usage 7 Engine Control
Module
9 Cooling Fan
13 Cooling Fan
15 Run/Crank
16 AIR Pump
17 Rear Window
Defogger

Black plate (51,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-51
Tire Designations
Tire Size
The following is an example of a
typical passenger vehicle
tire size.
(A) Passenger (P‐Metric) Tire:
The United States version of a
metric tire sizing system. The
letter P as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire
and Rim Association.
(B) Tire Width
:The three‐digit
number indicates the tire section
width in millimeters from
sidewall to sidewall. (C) Aspect Ratio
:A two‐digit
number that indicates the tire
height‐to‐width measurements.
For example, if the tire size
aspect ratio is 60, as shown in
item C of the illustration, it would
mean that the tire's sidewall is
60 percent as high as it is wide.
(D) Construction Code
:A
letter code is used to indicate
the type of ply construction in
the tire. The letter R means
radial ply construction; the
letter D means diagonal or bias
ply construction; and the letter B
means belted‐bias ply
construction.
(E) Rim Diameter
:Diameter of
the wheel in inches.
(F) Service Description
:These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, power
steering, power brakes, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.

Black plate (59,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-59
.Replacement tires or wheels do
not match the original equipment
tires or wheels. Tires and wheels
other than those recommended
could prevent the TPMS from
functioning properly. SeeBuying
New Tires on page 10‑63.
.Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning
properly it cannot detect or signal a
low tire condition. See your dealer
for service if the TPMS malfunction
light and DIC message comes on
and stays on.
TPMS Sensor Matching
Process
Each TPMS sensor has a unique
identification code. The identification
code needs to be matched to a new
tire/wheel position after rotating the
vehicle’s tires or replacing one or
more of the TPMS sensors. The
TPMS sensor matching process
should also be performed after
replacing a spare tire with a road
tire containing the TPMS sensor.
The malfunction light and the DIC
message should go off at the next
ignition cycle. The sensors are
matched to the tire/wheel positions,
using a TPMS relearn tool, in the
following order: driver side front tire,
passenger side front tire, passenger
side rear tire, and driver side rear.
See your dealer for service or to
purchase a relearn tool. There are two minutes to match the
first tire/wheel position, and
five minutes overall to match all four
tire/wheel positions. If it takes
longer, the matching process stops
and must be restarted.
The TPMS sensor matching
process is:
1. Set the parking brake.
2. Turn the ignition to ON/RUN with
the engine off.
3. Use the MENU button to select the Vehicle Information Menu in
the Driver Information
Center (DIC).
4. Use the thumbwheel to scroll to the Tire Pressure Menu Item
screen.
5. Press the SET/CLR button to begin the sensor matching
process.
A message asking if the process
should begin should appear.