service BUICK LACROSSE 2015 Workshop Manual

Black plate (46,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-46 Driving and Operating
When following a vehicle and
entering a curve, ACC may not
detect the vehicle ahead and
accelerate to the set speed. When
this happens, the vehicle ahead
symbol will not appear.
ACC may detect a vehicle that is
not in your lane and apply the
brakes.
ACC may occasionally provide an
alert and/or braking that is
considered unnecessary. It could
respond to vehicles in different
lanes, signs, guardrails, and other
stationary objects when entering or
exiting a curve. This is normal
operation. The vehicle does not
need service.Other Vehicle Lane Changes
ACC will not detect a vehicle ahead
until it is completely in the lane. The
brakes may need to be manually
applied.
Do Not Use ACC on Hills and
When Towing a TrailerDo not use ACC when driving on
steep hills or when towing a trailer.
ACC will not detect a vehicle in the
lane while driving on steep hills. The
driver will often need to take over
acceleration and braking on steep
hills, especially when towing a
trailer. If the brakes are applied, the
ACC disengages.

Black plate (48,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-48 Driving and Operating
Audible or Safety Alert Seat
Some driver assistance features
alert the driver of obstacles by
beeping. To change the volume of
the warning chime, see“Comfort
and Convenience” underVehicle
Personalization on page 5-45.
If equipped with the Safety Alert
Seat, the driver seat cushion may
provide a vibrating pulse alert
instead of beeping. To change this,
see “Collision/Detection Systems”
under Vehicle Personalization on
page 5-45.
Assistance Systems for
Parking or Backing
When the vehicle is in R (Reverse),
the Rear Vision Camera (RVC) and
Rear Parking Assist may help the
driver to avoid a crash or to reduce
crash damage while parking or
backing. Some models may also
have the Rear Cross Traffic Alert
(RCTA) feature. When the vehicle is shifted into
R (Reverse), the RVC displays an
image of the area behind the vehicle
in the center stack display. When
the vehicle is shifted out of
R (Reverse), the screen returns to
the previous content, after a short
delay. To return to this previous
screen sooner, press one of the
radio buttons. If the message
Service Rear Camera System is
displayed, the vehicle may need
service.
{Warning
The RVC system does not display
children, pedestrians, bicyclists,
crossing traffic, animals, or any
other object located outside the
camera's field of view, below the
bumper, or under the vehicle.
Perceived distances may be
different from actual distances.
Do not back the vehicle using
only the RVC screen. Failure to
(Continued)
Warning (Continued)
use proper care before backing
may result in injury, death,
or vehicle damage. Always check
behind and around the vehicle
before backing.
1. View Displayed by theCamera

Black plate (52,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-52 Driving and Operating
Collision Alert
When your vehicle approaches
another vehicle too rapidly, the red
collision alert symbol on the HUD,
will flash on the windshield. Either
eight beeps will sound from the
front, or both sides of the Safety
Alert Seat will pulse five times.
Tailgating Alert
The vehicle-ahead indicator will
display amber when you are
following a vehicle ahead much too
closely.
Selecting the Alert Timing
The Collision Alert control is on the
steering wheel. Press
[to set the
alert timing. The first button press
shows the current setting on the
DIC. Additional button presses will
change this setting. The chosen
setting will remain until it is changed
and will affect the timing of both the
Collision Alert and the Tailgating
Alert features. The timing of both
alerts will vary based on vehicle
speed. The faster the vehicle speed,
the farther away the alert will occur.
Consider traffic and weather
conditions when selecting the alert
timing. The range of selectable alert
timing may not be appropriate for all
drivers and driving conditions.
Changing the FCA timing setting
automatically changes the following
gap setting (Far, Medium, or Near)
for the Adaptive Cruise Control
(ACC) feature.
Following Distance Indication
The following distance to a moving
vehicle you are following is
indicated in following time in
seconds on the Driver Information
Center (DIC). See Driver
Information Center (DIC) on
page 5-28. The minimum following
time is 0.5 seconds away. If there is
no vehicle detected ahead, or the
vehicle ahead is out of sensor
range, dashes will be displayed.
Unnecessary Alerts
FCA may provide unnecessary
alerts for turning vehicles, vehicles
in other lanes, objects that are not
vehicles, or shadows. These alerts
are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to
operate properly, cleaning the
outside of the windshield in front of
the camera sensor and the front of
the vehicle may correct the issue.

Black plate (56,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-56 Driving and Operating
Left Side MirrorDisplayRight Side Mirror Display
When the vehicle is started, both
outside mirror LCA displays will
briefly come on to indicate the
system is operating. When the
vehicle is moving forward, the left or
right side mirror display will light up
if a vehicle is detected in the next
lane over in that blind zone or
rapidly approaching that zone. If the
turn signal is activated in the same
direction as a detected vehicle, this
display will flash as an extra
warning not to change lanes.
LCA can be disabled through
vehicle personalization using the
Side Blind Zone Alert option. See
“Collision/Detection Systems” under
Vehicle Personalization on page 5-45. If LCA is disabled by the
driver, the LCA mirror displays will
not light up.
When the System Does Not
Seem to Work Properly
The LCA system requires some
driving for the system to calibrate to
maximum performance. This
calibration may occur more quickly if
the vehicle is driving on a straight
highway road with traffic and
roadside objects (e.g., guardrails,
barriers).
LCA displays may not come on
when passing a vehicle quickly or
when towing a trailer. The LCA
detection zones that extend back
from the side of the vehicle do not
move further back when a trailer is
towed. Use caution while changing
lanes when towing a trailer. LCA
may alert to objects attached to the
vehicle, such as a trailer, bicycle,
or object extending out to either side
of the vehicle. Attached objects may
also interfere with the detection ofvehicles. This is normal system
operation; the vehicle does not need
service.
LCA may not always alert the driver
to vehicles in the next lane over,
especially in wet conditions or when
driving on sharp curves. The system
does not need to be serviced. The
system may light up due to
guardrails, signs, trees, shrubs, and
other non-moving objects. This is
normal system operation; the
vehicle does not need service.
LCA may not operate when the LCA
sensors in the left or right corners of
the rear bumper are covered with
mud, dirt, snow, ice, or slush, or in
heavy rainstorms. For cleaning
instructions, see "Washing the
Vehicle" under
Exterior Care on
page 10-85. If the DIC still displays
the system unavailable message
after cleaning both sides of the
vehicle toward the rear corners of
the vehicle, see your dealer.

Black plate (57,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-57
If the LCA displays do not light up
when vehicles are in the side blind
zone or rapidly approaching this
zone and the system is clean, the
system may need service. Take the
vehicle to your dealer.
When LCA is disabled for any
reason other than the driver turning
it off, the Side Blind Zone Alert On
option will not be available on the
personalization menu.
Radio Frequency Information
SeeRadio Frequency Statement on
page 13-12.
Lane Departure
Warning (LDW)
If equipped, LDW may help avoid
crashes due to unintentional lane
departures. It may provide an alert if
the vehicle is crossing a lane
without using a turn signal in that
direction. LDW uses a camera
sensor to detect the lane markings
at speeds of 56 km/h (35 mph) or
greater.
{Warning
The LDW system does not steer
the vehicle. The LDW system
may not:
.Provide enough time to avoid
a crash.
.Detect lane markings under
poor weather or visibility
conditions. This can occur if
the windshield or headlamps
are blocked by dirt, snow,
or ice; if they are not in
proper condition; or if the sun
shines directly into the
camera.
.Detect road edges.
.Detect lanes on winding or
hilly roads.
If LDW only detects lane
markings on one side of the road,
it will only warn you when
departing the lane on the side
where it has detected a lane (Continued)
Warning (Continued)
marking. Always keep your
attention on the road and
maintain proper vehicle position
within the lane, or vehicle
damage, injury, or death could
occur. Always keep the
windshield, headlamps, and
camera sensors clean and in
good repair. Do not use LDW in
bad weather conditions.
How the System Works
The LDW camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LDW on and off, press
@on
the center stack. The control
indicator will light when LDW is on.

Black plate (58,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-58 Driving and Operating
When LDW is on,@is green if
LDW is available to warn of a lane
departure. If the vehicle crosses a
detected lane marking without using
the turn signal in that direction,
@
changes to amber and flashes.
Additionally, there will be three
beeps, or the driver seat will pulse
three times on the right or left,
depending on the lane departure
direction.
When the System Does Not
Seem to Work Properly
The system may not detect lanes as
well when there are:
.Close vehicles ahead.
.Sudden lighting changes, such
as when driving through tunnels.
.Banked roads.
If the LDW system is not functioning
properly when lane markings are
clearly visible, cleaning the
windshield may help.
LDW alerts may occur due to tar
marks, shadows, cracks in the road,
temporary or construction lane
markings, or other road
imperfections. This is normal system
operation; the vehicle does not need
service. Turn LDW off if these
conditions continue.
Fuel
Use of the recommended fuel is an
important part of the proper
maintenance of this vehicle. When
driving in the U.S. and Canada, to
help keep the engine clean and
maintain optimum vehicle
performance, we recommend using
TOP TIER Detergent Gasolines.
See www.toptiergas.com for a list of
TOP TIER Detergent Gasolines.

Black plate (59,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-59
If the vehicle has a yellow fuel cap,
E85 or FlexFuel can be used in the
vehicle. SeeE85 or FlexFuel on
page 9-60.
Use regular unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 87 or
higher. Do not use gasoline with an
octane rating below 87, as it may
cause engine damage and will lower
fuel economy.
Use of Seasonal Fuels
Use summer and winter fuels in the
appropriate season. The fuels
industry automatically modifies the
fuel for the appropriate season.
If fuel is left in the vehicle tank for
long periods of time, driving or
starting could be affected. Drive the
vehicle until the fuel is at one-half
tank or less, then refuel with the
current seasonal fuel.
Prohibited Fuels
Gasolines containing oxygenates
such as ethers and ethanol, as well
as reformulated gasolines, are available in some cities. If these
gasolines comply with the
previously described specification,
then they are acceptable to use.
However, E85 (85% ethanol) and
other fuels containing more than
15% ethanol must be used only in
FlexFuel vehicles.
{Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Some gasolines, mainly high octane
racing gasolines, can contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use
gasolines and/or fuel additives with
MMT as they can reduce spark plug
life and affect emission control
system performance. The malfunction indicator lamp may turn
on. If this occurs, see your dealer
for service.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control
label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance might
be affected. The malfunction
indicator lamp could turn on and the
vehicle may not pass a smog-check
test. See
Malfunction Indicator
Lamp on page 5-16. If this occurs,
return to your authorized dealer for
diagnosis. If it is determined that the
condition is caused by the type of
fuel used, repairs may not be
covered by the vehicle warranty.

Black plate (65,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-65
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park)
for a few minutes before turning the
engine off. If the overheat warning
comes on, seeEngine Overheating
on page 10-21.Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load. 4. Reapply the brake pedal. Then
apply the parking brake and shift
into P (Park).
5. Release the brake pedal.Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11-2. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle

Black plate (1,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
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 . . . . . . . . . . . . . . . . . . 10-11
Engine Oil Life System . . . . . 10-13
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-15
Engine Air Cleaner/Filter . . . . 10-15
Cooling System . . . . . . . . . . . . 10-17
Engine Coolant . . . . . . . . . . . . . 10-19
Engine Overheating . . . . . . . . 10-21
Overheated Engine Protection
Operating Mode . . . . . . . . . . . 10-23 Power Steering Fluid (2.4L
L4 Engine and 3.6L
V6 Engine with FWD) . . . . . 10-23
Power Steering Fluid (3.6L V6 Engine with AWD) . . . . . 10-23
Washer Fluid . . . . . . . . . . . . . . . 10-24
Brakes . . . . . . . . . . . . . . . . . . . . . 10-25
Brake Fluid . . . . . . . . . . . . . . . . . 10-26
Battery . . . . . . . . . . . . . . . . . . . . . 10-27
All-Wheel Drive . . . . . . . . . . . . . 10-28
Starter Switch Check . . . . . . . 10-28
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-29
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-29
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-29
Wiper Blade Replacement . . . . . . . . . . . . . . 10-30
Windshield Replacement . . . 10-30
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-31
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-31
Halogen Bulbs . . . . . . . . . . . . . . 10-31 High Intensity Discharge
(HID) Lighting . . . . . . . . . . . . . 10-31
LED Lighting . . . . . . . . . . . . . . . 10-31
Headlamps, Front Turn Signal and Parking
Lamps . . . . . . . . . . . . . . . . . . . . 10-32
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-33
License Plate Lamp . . . . . . . . 10-33
Replacement Bulbs . . . . . . . . . 10-34
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . 10-34
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-35
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-35
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-36
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-40
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-42
All-Season Tires . . . . . . . . . . . . 10-43
Winter Tires . . . . . . . . . . . . . . . . 10-43
Summer Tires . . . . . . . . . . . . . . 10-43

Black plate (2,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
10-2 Vehicle Care
Tire Sidewall Labeling . . . . . . 10-44
Tire Designations . . . . . . . . . . . 10-46
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-47
Tire Pressure . . . . . . . . . . . . . . . 10-50
Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . 10-51
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-51
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . 10-52
Tire Inspection . . . . . . . . . . . . . . 10-56
Tire Rotation . . . . . . . . . . . . . . . 10-56
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . 10-57
Buying New Tires . . . . . . . . . . . 10-58
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . 10-60
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . 10-60
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . 10-62
Wheel Replacement . . . . . . . . 10-62
Tire Chains . . . . . . . . . . . . . . . . . 10-63
If a Tire Goes Flat . . . . . . . . . . 10-63
Tire Sealant and Compressor Kit . . . . . . . . . . . 10-65 Storing the Tire Sealant and
Compressor Kit . . . . . . . . . . . 10-72
Tire Changing . . . . . . . . . . . . . . 10-72
Compact Spare Tire . . . . . . . . 10-77
Jump Starting
Jump Starting (On-board with eAssist Only) . . . . . . . . . 10-78
Jump Starting (with or without eAssist) . . . . . . . . . . . 10-79
Towing the Vehicle
Towing the Vehicle . . . . . . . . . 10-82
Recreational VehicleTowing . . . . . . . . . . . . . . . . . . . . 10-83
Appearance Care
Exterior Care . . . . . . . . . . . . . . . 10-85
Interior Care . . . . . . . . . . . . . . . . 10-89
Floor Mats . . . . . . . . . . . . . . . . . . 10-93
General Information
For service and parts needs, visit
your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks: