Page 378 of 512

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
Page 381 of 512
Black plate (43,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-43
Instrument Panel Fuse Block
The vehicle may not be equipped
with all of the fuses, relays, and
features shown. Fuses Usage
1 Steering Wheel
Controls Backlight
2 Body Control
Module 7
3 Body Control
Module 5
4 Radio
5 OnStar
6 Power Outlet 1
7 Power Outlet 2
8 Body Control
Module 1
9 Body Control
Module 4
10 Body Control
Module 8
(J‐Case Fuse) Fuses Usage
11 Front Heater
Ventilation Air
Conditioning/Blower
(J‐Case Fuse)
12 Passenger Seat
(Circuit Breaker)
13 Driver Seat (Circuit
Breaker)
14 Diagnostic Link
Connector
15 Airbag
16 Trunk
17 Heater Ventilation
Air Conditioning
Controller
18 Pre‐Fuse for Fuses
4 and 5
Page 383 of 512
Black plate (45,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-45
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Mini Fuses Usage
5 Not Used
6 Heated Steering
Wheel
—Run/Crank
(without eAssist) Mini Fuses Usage
7 Not Used
8 Not Used
12 Not Used
15 Not Used
16 Not Used Mini Fuses Usage
17 Not Used
18 Passive Entry/
Passive Start
Module
—Battery 1
(without eAssist)
19 Not Used
20 Run/Crank for Rear
Sunshade (without
eAssist), Ventilated
Seats (without
eAssist)
21 Not Used
22 Not Used
23 Not Used
24 Not Used
25 Not Used
26 Not Used
27 Not Used
28 Not Used
29 Not Used
Page 384 of 512
Black plate (46,1)Buick LaCrosse Owner Manual - 2012
10-46 Vehicle Care
Mini Fuses Usage30 Not Used
31 Electronic
Suspension Control
(without eAssist)
32 Rear Seat
Infotainment (without
eAssist)
33 All‐Wheel Drive
(without eAssist)
J‐Case Fuses Usage
1 Not Used
2 Not Used
3 Not Used
4 Not Used J‐Case
Fuses Usage
9 Not Used
10 Not Used 11 Not Used
13 Not Used
14 Not Used
34 Not Used
35 Passive Entry/
Passive Start
Module
—Battery 2
(without eAssist)
36 Not Used
37 Not Used Relays
Usage
K1 Not Used
K2 Run/Crank Relay for
Seat Ventilation
(without eAssist),
Sunshade (without
eAssist)
K3 Run Relay for
Heated Steering
Wheel (without
eAssist)
K4 Not Used
Page 389 of 512

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.
Page 407 of 512

Black plate (69,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-69
If a Tire Goes Flat
It is unusual for a tire to blow out
while driving, especially if the tires
are maintained properly. SeeTires
on page 10‑47. If air goes out of a
tire, it is much more likely to leak
out slowly. But if there is ever a
blowout, here are a few tips about
what to expect and what to do:
If a front tire fails, the flat tire
creates a drag that pulls the vehicle
toward that side. Take your foot off
the accelerator pedal and grip the
steering wheel firmly. Steer to
maintain lane position, and then
gently brake to a stop, well off the
road, if possible. A rear blowout, particularly on a
curve, acts much like a skid and
may require the same correction as
used in a skid. Stop pressing the
accelerator pedal and steer to
straighten the vehicle. It may be
very bumpy and noisy. Gently brake
to a stop, well off the road,
if possible.
{WARNING
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been
driven on while severely
underinflated or flat may cause a
blowout and a serious crash.
Never attempt to re-inflate a tire
that has been driven on while
severely underinflated or flat.
Have your dealer or an authorized
tire service center repair or
replace the flat tire as soon as
possible.
{WARNING
Lifting a vehicle and getting
under it to do maintenance or
repairs is dangerous without the
appropriate safety equipment and
training. If a jack is provided with
the vehicle, it is designed only for
changing a flat tire. If it is used for
anything else, you or others could
be badly injured or killed if the
vehicle slips off the jack. If a jack
is provided with the vehicle, only
use it for changing a flat tire.
If a tire goes flat, avoid further tire
and wheel damage by driving slowly
to a level place, well off the road,
if possible. Turn on the hazard
warning flashers. See Hazard
Warning Flashers on page 6‑4.
Page 442 of 512

Black plate (104,1)Buick LaCrosse Owner Manual - 2012
10-104 Vehicle Care
Keep the wheels clean using a soft,
clean cloth with mild soap and
water. Rinse with clean water. After
rinsing thoroughly, dry with a soft,
clean towel. A wax may then be
applied.
Notice:Chrome wheels and other
chrome trim may be damaged if
the vehicle is not washed after
driving on roads that have been
sprayed with magnesium,
calcium, or sodium chloride.
These chlorides are used on
roads for conditions such as ice
and dust. Always wash the
chrome with soap and water after
exposure.
Notice: To avoid surface damage,
do not use strong soaps,
chemicals, abrasive polishes,
cleaners, brushes, or cleaners
that contain acid on aluminum or
chrome-plated wheels. Use only
approved cleaners. Also, never
drive a vehicle with aluminum or
chrome-plated wheels through an
automatic car wash that uses
silicone carbide tire cleaning brushes. Damage could occur
and the repairs would not be
covered by the vehicle warranty.
Steering, Suspension, and
Chassis Components
Visually inspect front and rear
suspension and steering system for
damaged, loose, or missing parts or
signs of wear. Inspect power
steering lines and hoses for proper
hook-up, binding, leaks, cracks,
chafing, etc. Visually check constant
velocity joints, rubber boots, and
axle seals for leaks.
Body Component Lubrication
Lubricate all key lock cylinders,
hood hinges, liftgate hinges, and the
steel fuel door hinge unless the
components are plastic. Applying
silicone grease on weatherstrips
with a clean cloth will make them
last longer, seal better, and not stick
or squeak.
Underbody Maintenance
Use plain water to flush dirt and
debris from the vehicle's underbody.
Your dealer or an underbody car
washing system can do this. If not
removed, rust and corrosion can
develop.
Sheet Metal Damage
If the vehicle is damaged and
requires sheet metal repair or
replacement, make sure the body
repair shop applies anti-corrosion
material to parts repaired or
replaced to restore corrosion
protection.
Original manufacturer replacement
parts will provide the corrosion
protection while maintaining the
vehicle warranty.
Page 450 of 512

Black plate (4,1)Buick LaCrosse Owner Manual - 2012
11-4 Service and Maintenance
.Check tire inflation pressures.
SeeTire Pressure on
page 10‑54.
.Inspect tire wear. See Tire
Inspection on page 10‑60.
.Visually check for fluid leaks.
.Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10‑13.
.Inspect brake system.
.Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of
wear. See Exterior Care on
page 10‑102.
.Check restraint system
components. See Safety System
Check on page 3‑20.
.Visually inspect fuel system for
damage or leaks.
.Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts.
.Lubricate body components. See
Exterior Care on page 10‑102.
.Check starter switch. See Starter
Switch Check on page 10‑27.
.Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check on
page 10‑27.
.Check ignition transmission lock.
See Ignition Transmission Lock
Check on page 10‑28.
.Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check on
page 10‑28.
.Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
.Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. See your
dealer if service is required.
.Check tire sealant expiration
date, if equipped. See Tire
Sealant and Compressor Kit
(With Pressure Relief Button) on
page 10‑71 orTire Sealant and
Compressor Kit (With Pressure
Deflation Button) on page 10‑78.
.Inspect sunroof track and seal,
if equipped. See Sunroof on
page 2‑22.