engine power BUICK LACROSSE 2012 Owner's Guide

Black plate (34,1)Buick LaCrosse Owner Manual - 2012
9-34 Driving and Operating
Uplevel Display Shown, BaseModel Similar
The display on the instrument panel
cluster will show which gear the
vehicle is in. The number indicates
the requested gear range when
moving the shift lever forward or
rearward. The transmission will only allow
you to shift 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.
While in the DSC 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 second
gear. A higher gear allows you 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.
When using a compact spare tire on
an AWD vehicle, the system
automatically detects the compact
spare and disables AWD. To restore
AWD operation and prevent
excessive wear on the system,
replace the compact spare with a
full-size tire as soon as possible.
See
Compact Spare Tire on
page 10‑93 for more information.

Black plate (36,1)Buick LaCrosse Owner Manual - 2012
9-36 Driving and Operating
Parking Brake
The vehicle has an Electric Parking
Brake (EPB). The switch for the
EPB is in 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 system when the
engine is not running.
The system has a parking brake
status light and a parking brake
warning light. SeeElectric Parking
Brake Light on page 5‑21. There are
also three Driver Information Center (DIC) messages. See
Brake System
Messages on page 5‑36 for more
information. In case of insufficient
electrical power, the EPB cannot be
applied or released.
Before leaving the vehicle, check
the parking brake status light to
ensure that the parking brake is
applied.
EPB Apply
The EPB can be applied any time
the vehicle is stopped. The EPB is
applied by momentarily lifting up on
the EPB switch. Once fully applied,
the parking brake status light will be
on. While the brake is being applied,
the status light will flash until full
apply is reached. If the light does
not come on, or remains flashing,
have the vehicle serviced. Do not
drive the vehicle if the parking brake
status light is flashing. See your
dealer. See Electric Parking Brake
Light on page 5‑21 for more
information. If the EPB is applied while the
vehicle is in motion, a chime will
sound, and a DIC message will be
displayed. See
Brake System
Messages on page 5‑36. The
vehicle will decelerate as long as
the switch is held in the up position.
Releasing the EPB switch during
deceleration will release the parking
brake. If the switch is held in the up
position until the vehicle comes to a
stop, the EPB will remain applied.
If the parking brake status light
flashes continuously, the EPB is
only partially applied or released,
or there is a problem with the EPB.
A DIC message will be displayed.
See Brake System Messages on
page 5‑36. If this light flashes
continuously, release the EPB, and
attempt to apply it again. If this light
continues to flash, do not drive the
vehicle. See your dealer.

Black plate (38,1)Buick LaCrosse Owner Manual - 2012
9-38 Driving and Operating
Brake Assist
This vehicle has a brake assist
feature 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.
Hill Start Assist (HSA)
This vehicle has a Hill Start Assist
(HSA) feature, which may be useful
when the vehicle is stopped on a
grade. This feature is designed to
prevent the vehicle from rolling,
either forward or rearward, during
vehicle drive off. After the driver
completely stops and holds the
vehicle in a complete standstill on a
grade, HSA will be automatically
activated. During the transition
period between when the driver
releases the brake pedal and starts
to accelerate to drive off on a grade,
HSA holds the braking pressure to
ensure that there is no rolling. The
brakes will automatically release
when the accelerator pedal is
applied within the two‐second
window. It will not activate if the
vehicle is in a drive gear and facing
downhill or if the vehicle is facing
uphill and in R (Reverse).
Ride Control Systems
Traction Control
System (TCS)
The vehicle has a Traction Control
System (TCS) that limits wheel slip.
The system operates if it senses
that one or both of the front wheels
are slipping or beginning to lose
traction. When this happens, the
system reduces engine power and/
or applies brake pressure to the
slipping wheel(s).
The system may be heard or felt
while it is working, but this is
normal.
TCS automatically comes on
whenever the vehicle is started. To
limit wheel slip, especially in
slippery road conditions, the system
should always be left on. But, TCS
can be turned off if needed.

Black plate (1,1)Buick LaCrosse Owner Manual - 2012
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 . . . . . . . . . . . . . . . . . . . 10-9
Engine Oil Life System . . . . . 10-12
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-13
Engine Air Cleaner/Filter . . . . 10-13
Cooling System . . . . . . . . . . . . 10-15
Engine Coolant . . . . . . . . . . . . . 10-16
Engine Overheating . . . . . . . . 10-19
Overheated Engine Protection
Operating Mode . . . . . . . . . . . 10-21 Power Steering Fluid (2.4L
L4 Engine) . . . . . . . . . . . . . . . . 10-21
Power Steering Fluid (3.6L V6 Engine) . . . . . . . . . . . . . . . . 10-21
Washer Fluid . . . . . . . . . . . . . . . 10-22
Brakes . . . . . . . . . . . . . . . . . . . . . 10-23
Brake Fluid . . . . . . . . . . . . . . . . . 10-24
Battery . . . . . . . . . . . . . . . . . . . . . 10-25
Starter Switch Check . . . . . . . 10-27
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-27
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-28
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-28
Wiper Blade Replacement . . . . . . . . . . . . . . 10-29
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-30
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-33
Halogen Bulbs . . . . . . . . . . . . . . 10-33
High Intensity Discharge(HID) Lighting . . . . . . . . . . . . . 10-33 Headlamps, Front Turn
Signal and Parking
Lamps . . . . . . . . . . . . . . . . . . . . 10-33
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-35
License Plate Lamp . . . . . . . . 10-36
Replacement Bulbs . . . . . . . . . 10-36
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . 10-37
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-37
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-38
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . 10-38
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-42
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-44
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-47
Winter Tires . . . . . . . . . . . . . . . . 10-48
Tire Sidewall Labeling . . . . . . 10-48
Tire Designations . . . . . . . . . . . 10-51

Black plate (9,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-9
A.Engine Air Cleaner/Filter on
page 10‑13.
B. Power Steering Reservoir and Cap. See Power Steering Fluid
(2.4L L4 Engine) on page 10‑21
or Power Steering Fluid (3.6L
V6 Engine) on page 10‑21.
C. Engine Oil Fill Cap. See Engine
Oil on page 10‑9.
D. Engine Oil Dipstick. See Engine
Oil on page 10‑9.
E. Engine Cover.
F. Transmission Fluid Cap and Dipstick. See Automatic
Transmission Fluid on
page 10‑13. G. Brake Master Cylinder
Reservoir. See Brakes on
page 10‑23.
H. Coolant Surge Tank and Pressure Cap. See Engine
Coolant on page 10‑16.
I. Battery Cover. See Battery on
page 10‑25.
J. Engine Compartment Fuse
Block on page 10‑38.
K. Windshield Washer Fluid Reservoir. See Washer Fluid on
page 10‑22.Engine Oil
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
.Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
.Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10‑12.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.

Black plate (21,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-21
Overheated Engine
Protection
Operating Mode
This emergency operating mode
allows the vehicle to be driven to a
safe place in an emergency
situation. If an overheated engine
condition exists, an overheat
protection mode which alternates
firing groups of cylinders helps
prevent engine damage. In this
mode, there is significant loss in
power and engine performance.
2.4L L4 Engine
The engine coolant temperature
warning light comes on the
instrument panel, to indicate the
vehicle has entered overheated
engine protection operating mode.
Driving extended distances and/or
towing a trailer in the overheat
protection mode should be avoided.3.6L V6 Engine
The engine coolant temperature
warning light comes on the
instrument panel, to indicate the
vehicle has entered overheated
engine protection operating mode.
The temperature gauge also
indicates an overheat condition
exists. Driving extended distances
and/or towing a trailer in the
overheat protection mode should be
avoided.
Power Steering Fluid
(2.4L L4 Engine)
The vehicle has electric power
steering and does not use power
steering fluid.
Power Steering Fluid
(3.6L V6 Engine)
See
Engine Compartment Overview
on page 10‑6 for information on the
location of the power steering fluid
reservoir.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless a
leak is suspected in the system or
an unusual noise is heard. A fluid
loss in this system could indicate a
problem. Have the system inspected
and repaired.

Black plate (22,1)Buick LaCrosse Owner Manual - 2012
10-22 Vehicle Care
How to Check Power Steering
Fluid
Check the level after the vehicle has
been driven for at least 20 minutes
so the fluid is warm.
To check the power steering fluid:
1. Turn the ignition to LOCK/OFFand let the engine compartment
cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and pull it straight up.
4. Wipe the dipstick with a clean rag.
5. Replace the cap and completely tighten it.
6. Remove the cap again and look at the fluid level on the dipstick.
When the engine is hot, the level
should be at the hot MAX level.
When the engine is cold, the fluid
level should be between MIN and
MAX on the dipstick.
What to Use
To determine what kind of fluid to
use, see Recommended Fluids and
Lubricants on page 11‑12. Always
use the proper fluid.
Washer Fluid
What to Use
When windshield washer fluid is
needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an
area where the temperature may fall
below freezing, use a fluid that has
sufficient protection against
freezing.
Adding Washer Fluid
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. See Engine
Compartment Overview on
page 10‑6 for reservoir location.

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 (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.