BUICK LACROSSE 2012 Owner's Manual

Black plate (33,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-33
Bulb Replacement
For the proper type of replacement
bulbs, seeReplacement Bulbs on
page 10‑36.
For any bulb changing procedure
not listed in this section, contact
your dealer.
Halogen Bulbs
{WARNING
Halogen bulbs have pressurized
gas inside and can burst if you
drop or scratch the bulb. You or
others could be injured. Be sure
to read and follow the instructions
on the bulb package.
High Intensity Discharge
(HID) Lighting
{WARNING
The low beam high intensity
discharge lighting system
operates at a very high voltage.
If you try to service any of the
system components, you could be
seriously injured. Have your
dealer or a qualified technician
service them.
After an HID headlamp bulb has
been replaced, the beam might be a
slightly different shade than it was
originally. This is normal.
Headlamps, Front Turn
Signal and Parking
Lamps
Base Headlamp Assembly
The base model vehicle has a
halogen high-beam headlamp, a
low-beam/Daytime Running Lamp
(DRL) headlamp, and a turn signal/
parking lamp on the headlamp
assembly.
For replacement of the turn signal/
parking lamp bulb on an eAssist
vehicle, contact your dealer.

Black plate (34,1)Buick LaCrosse Owner Manual - 2012
10-34 Vehicle Care
To replace one of these bulbs:
1. Open the hood. SeeHood on
page 10‑5.
A. Low-Beam Headlamp/DRL
B. High-Beam Headlamp
C. Parking/Turn Signal Lamp
2. If replacing a headlamp bulb, remove the dust cover from the
back of the headlamp housing
by turning counterclockwise
one‐quarter turn. 3. If replacing a turn signal/parking
lamp bulb on a non‐eAssist
vehicle, remove the close out
panel push pins and close out
panel covering the bulb socket.
4. Remove the bulb socket from the headlamp by turning
counterclockwise
one‐quarter turn.
5. Remove the bulb from the socket. If replacing the
high/low‐beam bulb, pry the two
clips on either end of the bulb
and pull straight out.
6. Install the new bulb in the socket. 7. Install the bulb socket by turning
clockwise one‐quarter turn.
8. If a headlamp bulb was replaced, install the dust cover in
the back of the headlamp
housing by turning clockwise
one‐quarter turn.
Uplevel Headlamp Assembly
The uplevel model vehicle has a
high intensity discharge (HID) high/
low beam, a dedicated DRL, and a
parking/turn signal lamp on the
headlamp assembly. See High
Intensity Discharge (HID) Lighting
on page 10‑33 for more information.

Black plate (35,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-35
To replace one of these bulbs:
1. Open the hood. SeeHood on
page 10‑5.
A. DRL Lamp
B. Parking/Turn Signal Lamp
2. Turn the bulb socket counterclockwise to remove it
from the headlamp assembly.
3. Pull the bulb straight out from the socket. 4. Push the new bulb into the
socket and reinstall the socket
into the headlamp assembly by
turning it clockwise.
Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps
A. Back‐Up Lamp
B. Turn Signal Lamp To replace one of these lamps:
1. Open the trunk. See
Trunk on
page 2‑13.
2. Remove the fasteners and pull back the trunk trim.
3. Remove the four plastic wing nuts holding the taillamp
assembly in place.
4. Pull out the taillamp assembly and disconnect the wiring
harness.
5. Turn the bulb socket counterclockwise to remove it.
6. Pull the old bulb straight out of the bulb socket.
7. Reverse Steps 1 through 6 to install.

Black plate (36,1)Buick LaCrosse Owner Manual - 2012
10-36 Vehicle Care
License Plate Lamp
The license plate lamps for this
vehicle are on the trunk lid.
To replace one of these bulbs:
1. Open the trunk. SeeTrunk on
page 2‑13 for more information.
2. Push the end on either of the
lamp assemblies (passenger
side shown) and then move the
lamp assembly down to remove
it from the trunk lid.
A. Bulb Socket
B. Bulb
C. Lamp Assembly
3. Turn the bulb socket (A) counterclockwise to remove it
from the lamp assembly (C).
4. Pull the bulb (B) straight out of the bulb socket.
5. Push the replacement bulb straight into the bulb socket and
turn the bulb socket clockwise to
install it into the lamp assembly.
6. Move the lamp assembly into the trunk lid, engaging the clip
side first. 7. Push on the lamp side opposite
the clip until the lamp assembly
snaps into place.
Replacement Bulbs
Exterior Lamp Bulb
Number
Back-Up Lamp 921LL
Daytime Running
Lamp (Uplevel) 3157K LCP
Front Turn Signal/
Parking Lamp 3757NAK
LCP
Headlamp High
Beam (Base) H9
Headlamp Low
Beam (Base) H11LL
License Plate Lamp W5WLL
Rear Turn Signal 3757NAK
LCP
For replacement bulbs not listed
here, contact your dealer.

Black plate (37,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-37
Electrical System
High Voltage Devices and
Wiring
{WARNING
Exposure to high voltage can
cause shock, burns, and even
death. The high voltage
components in the vehicle can
only be serviced by technicians
with special training.
High voltage components are
identified by labels. Do not
remove, open, take apart,
or modify these components.
High voltage cable or wiring has
orange covering. Do not probe,
tamper with, cut, or modify high
voltage cable or wiring.
Electrical System
Overload
The vehicle has fuses and circuit
breakers to protect against an
electrical system overload.
When the current electrical load is
too heavy, the circuit breaker opens
and closes, protecting the circuit
until the current load returns to
normal or the problem is fixed. This
greatly reduces the chance of circuit
overload and fire caused by
electrical problems.
Fuses and circuit breakers protect
power devices in the vehicle.
Replace a bad fuse with a new one
of the identical size and rating.
If there is a problem on the road and
a fuse needs to be replaced, the
same amperage fuse can be
borrowed. Choose some feature of
the vehicle that is not needed to use
and replace it as soon as possible.
Headlamp Wiring
An electrical overload may cause
the lamps to go on and off, or in
some cases to remain off. Have the
headlamp wiring checked right away
if the lamps go on and off or
remain off.
Windshield Wipers
If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop until the motor cools
and will then restart.
Although the circuit is protected
from electrical overload, overload
due to heavy snow or ice may
cause wiper linkage damage.
Always clear ice and heavy snow
from the windshield before using the
windshield wipers.
If the overload is caused by an
electrical problem and not snow or
ice, be sure to get it fixed.

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 (42,1)Buick LaCrosse Owner Manual - 2012
10-42 Vehicle Care
Micro
Relays Usage
1 Air Conditioning
Compressor Clutch
2 Starter
4 Wiper Speed
5 Wiper Control
6 Cabin Heater
Coolant Pump
(eAssist)
10 Cooling Fan
14 Headlamp
Low Beam
Ultra Micro Relays Usage
11 Transmission
Auxiliary Oil Pump
(eAssist)Instrument Panel Fuse
Block
The instrument panel fuse block is
located in the instrument panel, on
the driver side of the vehicle. To
access the fuses, open the fuse
panel door by pulling down at
the top.
Press in on the sides of the door to
release it from the instrument panel.
Pull the door toward you to release
it from the hinge.