Page 369 of 512
Black plate (31,1)Buick LaCrosse Owner Manual - 2012
Vehicle Care 10-31
Uplevel
2. Locate the aim dot on the lens of the low‐beam headlamp.
3. Measure the distance from the ground to the aim dot on the
low‐beam headlamp. Record the
distance.
4. At the wall, measure from theground upward (A) to the
recorded distance from
Step 3 and mark it.
5. Draw or tape a horizontal line (B) on the wall the width of the
vehicle at the height of the mark
in Step 4. Notice:
Do not cover a headlamp
to improve beam cut-off when
aiming. Covering a headlamp may
cause excessive heat build-up
which may cause damage to the
headlamp.
6. Turn on the low-beam
headlamps and place a piece of
cardboard or equivalent in front
of the headlamp not being
adjusted. This allows only the
beam of light from the headlamp
being adjusted to be seen on the
flat surface.
Page 370 of 512
Black plate (32,1)Buick LaCrosse Owner Manual - 2012
10-32 Vehicle Care
Base
Uplevel7. Locate the vertical headlamp
aiming screws, which are under
the hood near each headlamp
assembly.
8. Turn the vertical aiming screw until the headlamp beam is
aimed to the horizontal tape line.
Turn it clockwise or
counterclockwise to raise or
lower the angle of the beam.
9. Make sure that the light from the
headlamp is positioned at the
bottom edge of the horizontal
tape line. The lamp on the
left (A) shows the correct
headlamp aim. The lamp on the
right (B) shows the incorrect
headlamp aim.
10. Repeat Steps 7 through 9 for the opposite headlamp.
Page 371 of 512

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.
Page 372 of 512

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.
Page 373 of 512
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.
Page 374 of 512

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.
Page 375 of 512

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.
Page 376 of 512

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.