
Black plate (5,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Lighting 6-5
To turn on the fog lamps, the ignition
and the headlamps or parking lamps
must be on.
If the fog lamps are turned on while
the exterior lamp control is in the
AUTO position, the headlamps
come on automatically.
#(Fog Lamps):Press to turn on
or off. An indicator light on the
instrument cluster comes on when
the fog lamps are on.
Some localities have laws that
require the headlamps to be on
along with the fog lamps.
Interior Lighting
Instrument Panel
Illumination Control
The brightness of the instrument
panel lighting and steering wheel
controls can be adjusted.
D(Instrument Panel
Illumination): Move and hold the
thumbwheel up or down to brighten
or dim the lights.
Dome Lamps
The interior lamps control in the
overhead console controls both the
front and rear interior lamps.
To operate:
((Off): Turns the lamps off.
H(Door): Turns the lamps on
when any door is opened.
'(On): Keeps the lamps on all
the time.
The interior lamps turn on
automatically if the airbags are
deployed.

Black plate (7,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Lighting 6-7
Exit Lighting
The headlamps, taillamps, back-up
lamps, parking lamps, and license
plate lamps come on at night, or in
areas with limited lighting, when the
key is removed from the ignition.
The dome lamps also come on
when the key is removed from the
ignition. The exterior lamps and
dome lamps remain on after the
door is closed for a set amount of
time, then automatically turn off.
If equipped with Keyless Access,
the exterior lamps and dome lamps
automatically turn on when the
driver door is opened after the
ignition is turned off. SeeIgnition
Positions (Key Access) on
page 9-15 orIgnition Positions
(Keyless Access) on page 9-16.
The exterior lamps turn off
immediately by turning the exterior
lamp control off.
This feature can be changed. See
Vehicle Personalization on
page 5-45.
Battery Load
Management
The vehicle has Electric Power
Management (EPM) that estimates
the battery's temperature and state
of charge. It then adjusts the voltage
for best performance and extended
life of the battery.
When the battery's state of charge
is low, the voltage is raised slightly
to quickly bring the charge back up.
When the state of charge is high,
the voltage is lowered slightly to
prevent overcharging. If the vehicle
has a voltmeter gauge or a voltage
display on the Driver Information
Center (DIC), you may see the
voltage move up or down. This is
normal. If there is a problem, an
alert will be displayed.
The battery can be discharged at
idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fast enough at idle to produce all of the
power needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power whenever
needed. It can temporarily reduce
the power demands of some
accessories.
Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,
this action may be noticeable to the
driver. If so, a DIC message might
be displayed and it is recommended

Black plate (2,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
8-2 Climate Controls
3. Fan Control
4. Air Delivery Mode Controls
5. Defrost
6. SYNC (SynchronizedTemperature)
7. Power
8. A/C (Comfort and Eco Air Conditioning)
9. Recirculation
10. Rear Window Defogger
11. AUTO (Automatic Operation)
Climate Control Influence on
eAssist Operation and Fuel
Economy (If Equipped)
The climate control system depends
on other vehicle systems for heat
and power input. Certain climate
control settings can lead to higher
fuel usage and/or fewer auto stops.
The following are climate control
settings that use more fuel:
.Comfort air conditioning mode.
.The defrost mode.
.Extreme temperature settings,
such as 15°C (60°F) or 32°C
(90°F).
.High fan speed settings.
To help reduce fuel usage:
.Use the full automatic control as
described under “Automatic
Operation.”
.Select a temperature setting that
is higher in hot weather and
lower in cold weather.
.Turn off the air conditioning
when it is not needed.
.Only use defrost to clear the
windows.
Automatic Operation
The system automatically controls
the fan speed, air delivery, air
conditioning, and recirculation in
order to heat or cool the vehicle to
the desired temperature.
When the AUTO indicator light is
on, the system is in full automatic
operation. If the air delivery mode,
fan speed, recirculation, or air conditioning setting is adjusted, the
AUTO indicator turns off and the
selected settings will appear on the
display.
To place the system in automatic
mode do the following:
1. Press AUTO.
2. Set the temperature. Allow the
system time to stabilize. Adjust
the temperature as needed for
best comfort.
To improve fuel efficiency and to
cool the vehicle faster, recirculation
may be automatically selected in
warm weather. The recirculation
light will not come on. Press
@to
select recirculation; press it again to
select outside air.
Q/R(Driver and Passenger
Temperature Controls): The
temperature can be adjusted
separately for the driver and the
passenger. Press to increase or
decrease the temperature.

Black plate (3,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Climate Controls 8-3
SYNC (Synchronized
Temperature):Press to link all
climate zone settings to the driver
settings. The SYNC indicator light
will turn on. When the passenger
settings are adjusted, the SYNC
indicator light is off.
Manual Operation
O(Power): Press to turn the fan off
or on.
Q 9 R(Fan Control): Press to
increase or decrease the fan speed.
The fan speed setting appears on
the main display. Pressing either
button cancels automatic fan control
and the fan is controlled manually.
Press AUTO to return to automatic
operation.
Air Delivery Mode Controls:
Press
-,Y, or[to change the
direction of the airflow. The current
mode appears in the display screen.
Pressing either button cancels
automatic air delivery control and the direction of the airflow is
controlled manually. Press AUTO to
return to automatic operation.
To change the current mode, select
one of the following:
-(Defog):
Clears the windows of
fog or moisture. Air is directed to the
windshield and floor outlets.
Y(Vent): Air is directed to the
instrument panel outlets.
[(Floor): Air is directed to the
floor outlets.
0MAX (Defrost): Clears the
windshield of fog or frost more
quickly. Air is directed to the
windshield.
For best results, clear all snow and
ice from the windshield before
defrosting.
For eAssist vehicles that have the
auto defog feature, auto stops can
occur in defrost mode. In this mode,
the auto stops are shorter and less
frequent than other air delivery
modes to prevent window fogging. A/C (Comfort Air Conditioning):
Press to turn the air conditioning
system on or off. If the climate
control system is turned off or the
outside temperature falls below
freezing, the air conditioner will
not run.
Pressing this button cancels
automatic air conditioning and turns
off the air conditioner. Press AUTO
to return to automatic operation and
the air conditioner runs
automatically as needed. When the
indicator light is on, the air
conditioner runs automatically to
cool the air inside the vehicle or to
dry the air needed to defog the
windshield faster.
For eAssist vehicles, an auto stop
may occur if the climate control
system determines the a/c
compressor can be shut off and still
maintain comfort levels with minimal
windshield fogging.
Eco A/C (For eAssist Vehicles):
Press to cycle between the off, eco
and comfort air conditioning modes.

Black plate (4,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
8-4 Climate Controls
The indicator will be lit green in eco,
amber in comfort, and turns off
when there is no A/C function. If the
fan is turned off the A/C will not run.
The eco A/C setting balances fuel
economy and air conditioning
comfort. In warm weather
conditions, auto stops may occur
more frequently and the vehicle
interior may be warmer as
compared to the comfort air
conditioning. This setting allows
higher humidity inside the vehicle
and window fogging before the
engine restarts.
Pressing the
0button during an
auto stop may restart the engine to
prevent window fogging. To reach
comfort levels quickly during an
auto stop, the engine will restart if
the air conditioner is off and AUTO
or A/C is selected.
If temperature controls are adjusted
cooler by more than 1°C (1°F)
during an auto stop, the engine will
restart to ensure that comfort is
reached.
@(Recirculation): Press to turn
on recirculation. An indicator light
comes on. Air is recirculated to
quickly cool the air inside the
vehicle or prevent odors from
entering. Press again to change to
outside air and the indicator light
turns off.
Press AUTO to return to automatic
operation and recirculation runs
automatically as needed. The
indicator light is off.
The Air Quality Sensor may operate
the recirculation mode automatically.
See “Climate and Air Quality” under
Vehicle Personalization on
page 5-45.
Auto Defog: The climate control
system may have a sensor to
automatically detect high humidity
inside the vehicle. When high
humidity is detected, the climate
control system may adjust to
outside air supply and turn on the
air conditioner. The fan speed may
slightly increase to help prevent
fogging. If the climate control system does not detect possible
window fogging, it returns to normal
operation. For eAssist vehicles,
there may be shorter and less
frequent auto stops when auto
defog is in use.
To turn Auto Defog off or on, see
“Climate and Air Quality”
under
Vehicle Personalization on
page 5-45.
Rear Window Defogger
=(Rear Window Defogger):
Press to turn the rear window
defogger on or off. An indicator light
on the button comes on to show that
the rear window defogger is on.
The defogger can be turned off by
turning the ignition to ACC/
ACCESSORY or LOCK/OFF.
The rear window defogger can be
set to automatic operation. See
“Climate and Air Quality” under
Vehicle Personalization on
page 5-45. When auto rear defog is
selected, the rear window defogger
turns on automatically when the

Black plate (38,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
10-38 Vehicle Care
Mini Fuses Usage14 Cabin Heater Coolant Pump
(eAssist)/Secondary
Air Injector/
Secondary Air
Injector with
Pressure Sensor
15 Motor Generator Unit Coolant Pump
(eAssist)
16 Run/Crank for eAssist Power
Inverter Module
17 Not Used
18 Sunshade Module, Vehicle Air
Purification System,
Ventilated Seats
20 Heated Steering Wheel (non eAssist) Mini Fuses Usage
23 Variable Effort Steering (if
equipped) or eAssist
Power Inverter
Module
29 Heated Seat, Left/ Power Lumbar
30 Heated Seat, Right/ Power Pack Cooling
Fan (eAssist)
31 All-Wheel Drive, Electronic
Suspension Control
32 Body Control Module 6
33 Memory Seat –
Front
34 Antilock Brake System Valves
35 Amplifier
36 Adaptive Forward Lighting (AFL)
Motors–Battery Mini Fuses Usage
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
48 Fog Lamps
49 Right High Intensity Discharge
Headlamp
50 Left High Intensity Discharge
Headlamp
51 Horn

Black plate (39,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-39
Mini Fuses Usage52 Cluster Run/Crank
53 Run/Crank for Inside Rearview Mirror,
Rear Vision Camera,
Air Quality Sensor,
Aero Shutter Motor
54 Run/Crank for: Heating, Ventilation
and Air
Conditioning,
Headlamp Switch
55 Outside Rearview Mirror, Universal
Remote System,
Front Window
Switches
56 Windshield Washer
60 Heated Mirror
62 Canister Vent
64 Adaptive Forward Lighting (AFL)
Module–Battery
65 Not Used Mini Fuses Usage
66 AIR Solenoid (eAssist)
67 Fuel Pump Power Module/Chassis
Control Module
69 Regulated Voltage Control Sensor
70 Parking Assist/Side Blind Zone
71 Passive Entry/ Passive Start
Mini Relays Usage 7 Engine Control Module
9 Cooling Fan
13 Cooling Fan
15 Run/Crank
16 AIR Pump
17 Rear Window Defogger Micro
Relays Usage
1 Air Conditioning Compressor Clutch
2 Starter
4 Wiper Speed
5 Wiper Control
6 Cabin Heater Coolant Pump
(eAssist)/Secondary
Air Injector/
Secondary Air
Injector with
Pressure Sensor
10 Cooling Fan
14 Headlamp Low Beam
Ultra Micro Relays Usage
11 Transmission Auxiliary Oil Pump
(eAssist)

Black plate (4,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
i-4 INDEX
Driving (cont'd)Vehicle Load Limits . . . . . . . . . . . 9-10
Wet Roads . . . . . . . . . . . . . . . . . . . . 9-6
Winter . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . 8-1
E
E85 or FlexFuel . . . . . . . . . . . . . . . 9-60
Electric Parking Brake Light . . . 5-20
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . 9-68
Electrical System Engine CompartmentFuse Block . . . . . . . . . . . . . . . . 10-36
Fuses and Circuit
Breakers . . . . . . . . . . . . . . . . . . 10-35
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . 10-40
Overload . . . . . . . . . . . . . . . . . . . 10-35
Emergency OnStar
®. . . . . . . . . . . . . . . . . . . . . . 14-2
Energy Information . . . . . . . . . . . . 5-27 Engine
Air Cleaner/Filter . . . . . . . . . . . 10-15
Check and Service Engine
Soon Light . . . . . . . . . . . . . . . . . . 5-16
Compartment Overview . . . . . . . 10-6
Coolant . . . . . . . . . . . . . . . . . . . . . 10-19
Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 5-13
Coolant Temperature Warning Light . . . . . . . . . . . . . . . 5-22
Cooling System . . . . . . . . . . . . . 10-17
Cooling System Messages . . . 5-38
Drive Belt Routing . . . . . . . . . . . . 12-4
Exhaust . . . . . . . . . . . . . . . . . . . . . . 9-26
Heater . . . . . . . . . . . . . . . . . . . . . . . . 9-22
Oil Life System . . . . . . . . . . . . . 10-13
Oil Messages . . . . . . . . . . . . . . . . . 5-38
Overheated Protection
Operating Mode . . . . . . . . . . . 10-23
Overheating . . . . . . . . . . . . . . . . 10-21
Power Messages . . . . . . . . . . . . . 5-39
Pressure Light . . . . . . . . . . . . . . . . 5-23
Running While Parked . . . . . . . . 9-26
Starting . . . . . . . . . . . . . . . . . . . . . . . 9-18
Entry Lighting . . . . . . . . . . . . . . . . . . . 6-6
Equipment, Towing . . . . . . . . . . . . 9-67 Event Data Recorders . . . . . . . . 13-14
Exit Lighting . . . . . . . . . . . . . . . . . . . . 6-7
Extender, Safety Belt . . . . . . . . . . 3-19
Exterior Lamp Controls . . . . . . . . . 6-1
Exterior Lamps Off Reminder . . . 6-2
F
Features
Memory . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Filter, Engine Air Cleaner . . . . . . . . . 10-15
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 6-2
Flashers, Hazard Warning . . . . . . 6-4
Flat Tire . . . . . . . . . . . . . . . . . . . . . . 10-63 Changing . . . . . . . . . . . . . . . . . . . 10-72
FlexFuel E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-60
Floor Mats . . . . . . . . . . . . . . . . . . . . 10-93
Fluid
Automatic Transmission . . . . 10-15
Brakes . . . . . . . . . . . . . . . . . . . . . . 10-26
Power Steering . . . . . . . . . . . . . 10-23
Washer . . . . . . . . . . . . . . . . . . . . . 10-24
Fog Lamps . . . . . . . . . . . . . . . . . . . . . 6-4
Folding Mirrors . . . . . . . . . . . . . . . . 2-19