2016 BUICK LACROSSE wiring

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9159288) - 2016 - CRC - 10/5/15
76 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 any
parts of the front seats, safety belts,
the airbag sensing and diagnostic
module, steering wheel, instrument
panel, any of the airbag modules,
ceiling 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-GMcovers, 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 071.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels 0280 for additional
important information.
If you have to modify your vehicle
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 0332.
Airbag System Check
The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See
Airbag Readiness Light 0112.
Caution
If an airbag covering is damaged,
opened, or broken, the airbag
may not work properly. Do not
open or break the airbag
coverings. If there are any
opened or broken airbag
coverings, have the airbag
covering and/or airbag module
replaced. For the location of the
airbags, see Where Are the
Airbags? 067. See your dealer
for service.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9159288) - 2016 - CRC - 10/5/15
112 Instruments and Controls
If the driver safety belt is buckled,
neither the light nor the chime
comes on.
Passenger Safety Belt
Reminder Light
There is a passenger safety belt
reminder light near the passenger
airbag status indicator. See
Passenger Sensing System071.
When the vehicle is started, this
light flashes and a chime may come
on to remind passengers to fasten
their safety belt. Then the light stays
on solid until the belt is buckled.
This cycle continues several times if
the passenger remains or becomes
unbuckled while the vehicle is
moving.
If the passenger safety belt is
buckled, neither the chime nor the
light comes on. The front passenger safety belt
reminder light and chime may turn
on if an object is put on the seat
such as a briefcase, handbag,
grocery bag, laptop, or other
electronic device. To turn off the
reminder light and/or chime, remove
the object from the seat or buckle
the safety belt.
Airbag Readiness Light
This light shows if there is an
electrical problem with the airbag
system. 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, see
Airbag
System 065.
The airbag readiness light comes on
for several seconds when the
vehicle is started. If the light does
not come on then, have it fixed
immediately.
{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 071 for important
safety information. The overhead
console has a passenger airbag
status indicator.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9159288) - 2016 - CRC - 10/5/15
226 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . 227
California Proposition65 Warning . . . . . . . . . . . . . . . . . 227
California Perchlorate Materials Requirements . . . . . 228
Accessories and Modifications . . . . . . . . . . . . . . . . 228
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 229
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 230
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 231
Engine Oil . . . . . . . . . . . . . . . . . . . . 236
Engine Oil Life System . . . . . . . 238
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 239
Engine Air Cleaner/Filter . . . . . . 239
Cooling System . . . . . . . . . . . . . . 242
Engine Coolant . . . . . . . . . . . . . . . 243
Engine Overheating . . . . . . . . . . 245
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 246 Power Steering Fluid (2.4L L4
Engine and 3.6L V6 Engine
with FWD) . . . . . . . . . . . . . . . . . . 247
Power Steering Fluid (3.6L V6 Engine with AWD) . . . . . . . 247
Washer Fluid . . . . . . . . . . . . . . . . . 247
Brakes . . . . . . . . . . . . . . . . . . . . . . . 248
Brake Fluid . . . . . . . . . . . . . . . . . . . 249
Battery - North America . . . . . . 250
All-Wheel Drive . . . . . . . . . . . . . . . 251
Starter Switch Check . . . . . . . . . 251
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 252
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 252
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 252
Wiper Blade Replacement . . . . 253
Windshield Replacement . . . . . 253
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 254
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 254
Halogen Bulbs . . . . . . . . . . . . . . . . 254
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 254
LED Lighting . . . . . . . . . . . . . . . . . 254 Headlamps, Front Turn Signal
and Parking Lamps . . . . . . . . . 255
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 256
License Plate Lamp . . . . . . . . . . 256
Replacement Bulbs . . . . . . . . . . . 257
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . . . 257
Electrical System Overload . . . 257
Fuses and Circuit Breakers . . . 258
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 259
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 262
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 264
All-Season Tires . . . . . . . . . . . . . . 265
Winter Tires . . . . . . . . . . . . . . . . . . 265
Summer Tires . . . . . . . . . . . . . . . . 265
Tire Sidewall Labeling . . . . . . . . 266
Tire Designations . . . . . . . . . . . . . 268
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . 268
Tire Pressure . . . . . . . . . . . . . . . . . 271
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 272

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9159288) - 2016 - CRC - 10/5/15
256 Vehicle Care
Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps
1. Back-Up Lamp
2. Turn Signal Lamp
To replace one of these lamps:1. Open the trunk. See Trunk 038.
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 1–6 to install.
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. See Trunk 038.2. 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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9159288) - 2016 - CRC - 10/5/15
Vehicle Care 257
3. Turn the bulb socket (1)counterclockwise to remove it
from the lamp assembly (3).
4. Pull the bulb (2) 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 (W16W)
Front Turn
Signal Lamp 7444NA
Headlamp High
Beam (Base) HIR2
Headlamp Low
Beam (Base) HIR2
License Plate Lamp W5WLL
Rear Turn Signal 7443NA (WY21W)
For replacement bulbs not listed
here, contact your dealer.
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 or labels. 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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9159288) - 2016 - CRC - 10/5/15
258 Vehicle Care
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.
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 0259 and
Instrument Panel Fuse Block 0262.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9159288) - 2016 - CRC - 10/5/15
Index 359
Front SeatsAdjustment . . . . . . . . . . . . . . . . . . . . . 52
Heated and Ventilated . . . . . . . . . . 56
Front Storage . . . . . . . . . . . . . . . . . . . . 98
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Additives . . . . . . . . . . . . . . . . . . . . . 216
Economy Driving . . . . . . . . . . . . . . . 25
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . 219
Filling the Tank . . . . . . . . . . . . . . . 217
Foreign Countries . . . . . . . . . . . . 216
Gauge . . . . . . . . . . . . . . . . . . . . . . . . .110
Low Fuel Warning Light . . . . . . . 120
Requirements, California . . . . . 216
System Messages . . . . . . . . . . . . 133
Fuses
Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . 259
Fuses and Circuit Breakers . . . 258
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 262
G
Garage Door Opener . . . . . . . . . . . 145
Programming . . . . . . . . . . . . . . . . . 145
Gauges
Engine CoolantTemperature . . . . . . . . . . . . . . . . . 111
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . .110 Gauges (cont'd)
Odometer . . . . . . . . . . . . . . . . . . . . . 109
Speedometer . . . . . . . . . . . . . . . . . 109
Tachometer . . . . . . . . . . . . . . . . . . . 109
Warning Lights and
Indicators . . . . . . . . . . . . . . . . . . . 105
General Information Service and Maintenance . . . . . 313
Towing . . . . . . . . . . . . . . . . . . . . . . . . 220
Vehicle Care . . . . . . . . . . . . . . . . . . 227
Glove Box . . . . . . . . . . . . . . . . . . . . . . . 97
GM Mobility Reimbursement Program . . . . . . . . . . . . . . . . . . . . . . . 334
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . 254
Hazard Warning Flashers . . . . . . . 151
Head Restraints . . . . . . . . . . . . . . . . . 50
Head-up Display . . . . . . . . . . . . . . . . 126
HeadlampsAdaptive ForwardLighting (AFL) . . . . . . . . . . . . . . . 150
Aiming . . . . . . . . . . . . . . . . . . . . . . . . 254
Automatic . . . . . . . . . . . . . . . . . . . . . 149
Bulb Replacement . . . . . . . . . . . . 254
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . 149
Flash-to-Pass . . . . . . . . . . . . . . . . . 149 Headlamps (cont'd)
High Intensity Discharge
(HID) Lighting . . . . . . . . . . . . . . . 254
High-Beam On Light . . . . . . . . . . 120
High/Low Beam Changer . . . . . 149
Lamps On Reminder . . . . . . . . . 121
Heated Steering Wheel . . . . . . . . . . . . . . . 101
Heated and Ventilated Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Heated Mirrors . . . . . . . . . . . . . . . . . . . 44
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . 181
High Voltage Devices and
Wiring . . . . . . . . . . . . . . . . . . . . . . . . . 257
High-Beam On Light . . . . . . . . . . . . 120
High-Speed Operation . . . . . . . . . . 272
Hill and Mountain Roads . . . . . . . . 168
Hill Start Assist (HSA) . . . . . . . . . . 192
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
How to Wear Safety Belts Properly . . . . . . . . . . . . . . . . . . . . . . . . 60
I
Ignition Positions . . . . . . . . . . 175, 176
Ignition Transmission LockCheck . . . . . . . . . . . . . . . . . . . . . . . . . 252
Immobilizer . . . . . . . . . . . . . . . . . . . . . . 41

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9159288) - 2016 - CRC - 10/5/15
Index 365
Tires (cont'd)Sealant and Compressor
Kit, Storing . . . . . . . . . . . . . . . . . . 291
Sidewall Labeling . . . . . . . . . . . . . 266
Terminology and Definitions . . 268
Uniform Tire Quality
Grading . . . . . . . . . . . . . . . . . . . . . 281
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 282
Wheel Replacement . . . . . . . . . . 282
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 278
Winter . . . . . . . . . . . . . . . . . . . . . . . . 265
Towing
Driving Characteristics . . . . . . . . 220
Equipment . . . . . . . . . . . . . . . . . . . . 224
General Information . . . . . . . . . . 220
Recreational Vehicle . . . . . . . . . . 301
Trailer . . . . . . . . . . . . . . . . . . . 222, 224
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 301
Traction Control System (TCS)/StabiliTrak
®Light . . . . . . . . . . . . .118
Limited-Slip Differential . . . . . . . 194
Off Light . . . . . . . . . . . . . . . . . . . . . . .117
Selective Ride Control . . . . . . . . 194
Traction Control/Electronic Stability Control . . . . . . . . . . . . . . . 192 Trailer
Towing . . . . . . . . . . . . . . . . . . . 222, 224
Transmission Automatic . . . . . . . . . . . . . . . . . . . . . 186
Fluid, Automatic . . . . . . . . . . . . . . 239
Messages . . . . . . . . . . . . . . . . . . . . 138
Transportation Program,
Courtesy . . . . . . . . . . . . . . . . . . . . . . 336
Trunk . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Turn and Lane-Change Signals . . . . . . . . . . . . . . . . . . . . . . . . 151
Turn Signal Bulb Replacement . . . . . . . . . . . . 256
U
Uniform Tire Quality Grading . . . 281
Universal Remote System . . . . . . 145Operation . . . . . . . . . . . . . . . . . . . . . 147
Programming . . . . . . . . . . . . . . . . . 145
Using This Manual . . . . . . . . . . . . . . . . 2
V
Vehicle Alarm System . . . . . . . . . . . . . . . . . . 40
Canadian Owners . . . . . . . . . . . . . . . 2
Control . . . . . . . . . . . . . . . . . . . . . . . 165
Identification Number (VIN) . . . 326
Load Limits . . . . . . . . . . . . . . . . . . . 171
Messages . . . . . . . . . . . . . . . . . . . . 130 Vehicle (cont'd)
Personalization . . . . . . . . . . . . . . . 139
Remote Start . . . . . . . . . . . . . . . . . . . 34
Security . . . . . . . . . . . . . . . . . . . . . . . . 40
Speed Messages . . . . . . . . . . . . . 138
Towing . . . . . . . . . . . . . . . . . . . . . . . . 301
Vehicle Ahead Indicator . . . . . . . . 117
Vehicle Care Storing the Tire Sealant
and Compressor Kit . . . . . . . . . 291
Tire Pressure . . . . . . . . . . . . . . . . . 271
Vehicle Data Recording and Privacy . . . . . . . . . . . . . . . . . . . . . . . . 342
Ventilation, Air . . . . . . . . . . . . . . . . . . 161
Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Voltage Devices and Wiring . . . . 257
W
Warning
Brake System Light . . . . . . . . . . . .115
Caution and Danger . . . . . . . . . . . . . 2
Lane Departure (LDW) . . . . . . . 213
Warning Lights, Gauges, and Indicators . . . . . . . . . . . . . . . . . . . . . 105
Warnings Hazard Flashers . . . . . . . . . . . . . . 151
Washer Fluid . . . . . . . . . . . . . . . . . . . 247
Wheels Alignment and Tire Balance . . 282