2012 BUICK LACROSSE wiring

Black plate (34,1)Buick LaCrosse Owner Manual - 2012
3-34 Seats and Restraints
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end or side sheet
metal, may keep the airbag system
from working properly. The
operation of the airbag system can
also be affected by changing or
moving any parts of the front seats,
safety belts, the airbag sensing and
diagnostic module, steering wheel,
instrument panel, roof-rail airbag
modules, ceiling headliner or pillar
garnish trim, front sensors, side
impact sensors, or airbag wiring.
Your dealer and the service manual
have information about the location
of the airbag sensors, sensing and
diagnostic module, and airbag
wiring.In addition, the vehicle has a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger seat. The
passenger sensing system may not
operate properly if the original seat
trim is replaced with non-GM
covers, upholstery or trim, or with
GM covers, upholstery or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort enhancing pad
or device, installed under or on top
of the seat fabric, could also
interfere with the operation of the
passenger sensing system. This
could either prevent proper
deployment of the passenger
airbag(s) or prevent the passenger
sensing system from properly
turning off the passenger airbag(s).
See
Passenger Sensing System on
page 3‑29. If your vehicle needs to be modified
because you have a disability and
you have questions about whether
the modifications will affect the
vehicle's airbag system, or if you
have questions about whether the
airbag system will be affected if the
vehicle is modified for any other
reason, call Customer Assistance.
See
Customer Assistance Offices
(U.S. and Canada) on page 13‑5 or
Customer Assistance Offices
(Mexico) on page 13‑5.

Black plate (16,1)Buick LaCrosse Owner Manual - 2012
5-16 Instruments and Controls
Airbag Readiness Light
This light shows if there is an
electrical problem. The system
check includes the airbag sensor(s),
passenger sensing system, the
pretensioners, the airbag modules,
the wiring, and the crash sensing
and diagnostic module. For more
information on the airbag system,
seeAirbag System on page 3‑22.
The airbag readiness light comes on
and stays on for several seconds
when the vehicle is started. Then
the light goes out.
{WARNING
If the airbag readiness light stays
on after the vehicle is started or
comes on while driving, it means
the airbag system might not be
working properly. The airbags in
the vehicle might not inflate in a
crash, or they could even inflate
without a crash. To help avoid
injury, have the vehicle serviced
right away.
Passenger Airbag Status
Indicator
The vehicle has a passenger
sensing system. See Passenger
Sensing System on page 3‑29 for
important safety information. The
instrument panel has a passenger
airbag status indicator.
When the vehicle is started, the
passenger airbag status indicator
will light ON and OFF for several
seconds as a system check.
If you are using remote start,
if equipped, to start the vehicle from
a distance, you may not see the
system check. Then, after several
more seconds, the status indicator
will light either ON or OFF to let you
know the status of the front
outboard passenger frontal airbag.
If the word ON is lit on the
passenger airbag status indicator, it
means that the front outboard
passenger frontal airbag is allowed
to inflate.

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 (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 (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 (6,1)Buick LaCrosse Owner Manual - 2012
i-6 INDEX
GaugesDriver Efficiency . . . . . . . . . . . . . . 5-13
Engine Coolant
Temperature . . . . . . . . . . . . . . . . 5-14
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Odometer . . . . . . . . . . . . . . . . . . . . . 5-12
Speedometer . . . . . . . . . . . . . . . . . 5-12
Tachometer . . . . . . . . . . . . . . . . . . . 5-12
Warning Lights and Indicators . . . . . . . . . . . . . . . . . . . . 5-9
General Information
Service and Maintenance . . . . . 11-1
Towing . . . . . . . . . . . . . . . . . . . . . . . . 9-57
Vehicle Care . . . . . . . . . . . . . . . . . . 10-2
Glove Box . . . . . . . . . . . . . . . . . . . . . . 4-1
GM Mobility Reimbursement Program . . . . . . . . . . . . . . . . . . . . . . 13-7
H
Halogen Bulbs . . . . . . . . . . . . . . . . 10-33
Hazard Warning Flashers . . . . . . . 6-4
Head Restraints . . . . . . . . . . . . . . . . 3-2
Head-up Display . . . . . . . . . . . . . . . 5-31 Headlamps
Adaptive Forward
Lighting (AFL) . . . . . . . . . . . . . . . . 6-3
Aiming . . . . . . . . . . . . . . . . . . . . . . 10-30
Automatic . . . . . . . . . . . . . . . . . . . . . . 6-3
Bulb Replacement . . . . . . . . . . 10-33
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . 6-2
Flash-to-Pass . . . . . . . . . . . . . . . . . . 6-2
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . 10-33
High-Beam On Light . . . . . . . . . . 5-26
High/Low Beam Changer . . . . . . 6-2
Lamps On Reminder . . . . . . . . . 5-26
Heated Steering Wheel . . . . . . . . . . . . . . . . 5-3
Heated and Ventilated Front Seats . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Heated Mirrors . . . . . . . . . . . . . . . . . 2-18
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . 9-26
Heating and Air Conditioning . . . 8-1 High Voltage Devices and
Wiring . . . . . . . . . . . . . . . . . . . . . . . 10-37
High-Beam On Light . . . . . . . . . . . 5-26
Highway Hypnosis . . . . . . . . . . . . . . 9-8
Hill and Mountain Roads . . . . . . . . 9-8
Hill Start Assist (HSA) . . . . . . . . . 9-38
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
How to Wear Safety Belts Properly . . . . . . . . . . . . . . . . . . . . . . 3-14
I
Ignition Positions . . . . . . . . 9-18, 9-20
Ignition Transmission LockCheck . . . . . . . . . . . . . . . . . . . . . . . 10-28
Immobilizer . . . . . . . . . . . . . . . . . . . . 2-15
Infants and Young Children, Restraints . . . . . . . . . . . . . . . . . . . . 3-38
Infotainment . . . . . . . . . . . . . . . . . . . . 7-1
Instrument Cluster . . . . . . . . . . . . . 5-10
Introduction . . . . . . . . . . . . . . . . . . . . . . . iii

Black plate (14,1)Buick LaCrosse Owner Manual - 2012
i-14 INDEX
Vehicle CareStoring the Tire Sealant
and Compressor Kit . . . . . . . 10-87
Tire Pressure . . . . . . . . . . . . . . . 10-54
Ventilation, Air . . . . . . . . . . . . . . . . . 8-10
Visors . . . . . . . . . . . . . . . . . . . . . . . . . 2-21
Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . . . 10-37
W
WarningBrake System Light . . . . . . . . . . . 5-20
Warning Lights, Gauges, and
Indicators . . . . . . . . . . . . . . . . . . . . . 5-9
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . iv Cautions and Danger . . . . . . . . . . . .iv
Hazard Flashers . . . . . . . . . . . . . . . 6-4
Washer Fluid . . . . . . . . . . . . . . . . . 10-22 Wheels
Alignment and Tire
Balance . . . . . . . . . . . . . . . . . . . 10-67
Different Size . . . . . . . . . . . . . . . 10-65
Replacement . . . . . . . . . . . . . . . 10-67
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-62
Where to Put the Restraint . . . . 3-43
Windows . . . . . . . . . . . . . . . . . . . . . . 2-19 Messages . . . . . . . . . . . . . . . . . . . . 5-42
Power . . . . . . . . . . . . . . . . . . . . . . . . 2-20
Windshield Wiper/Washer . . . . . . . . . . . . . . . . . 5-3
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . 9-9
Winter Tires . . . . . . . . . . . . . . . . . . 10-48
Wiper Blade Replacement . . . . 10-29
Wiring, High Voltage
Devices . . . . . . . . . . . . . . . . . . . . . 10-37