transmission BUICK LACROSSE 2015 Owner's Guide

Black plate (63,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-63
Trailer Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer. Read
the entire section before towing a
trailer.
For towing a disabled vehicle, see
Towing the Vehicle on page 10-82.
For towing the vehicle behind
another vehicle such as a motor
home, seeRecreational Vehicle
Towing on page 10-83.
Driving Characteristics
and Towing Tips
Driving with a Trailer
When towing a trailer:
.Become familiar with the state
and local laws that apply to
trailer towing.
.Do not tow a trailer during the
first 800 km (500 mi) to prevent
damage to the engine, axle,
or other parts.
.Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
.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.
.Do not use Adaptive Cruise
Control when towing.
.The Automatic Collision
Preparation System should be
set to Off when towing. See
Active Emergency Braking
System on page 9-53.
.Turn off Park Assist when
towing.
{Warning
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
When towing a trailer:
.Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
.Fully open the air outlets on
or under the instrument
panel.
.Also adjust the climate
control system to a setting
that brings in only outside air.
See “Climate Control
Systems” in the Index.
For more information about
Carbon Monoxide, see Engine
Exhaust on page 9-26.

Black plate (64,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-64 Driving and Operating
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
Passing
More passing distance is needed
when towing a trailer. The
combination will not accelerate as
quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
{Caution
Making very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.(Continued)
Caution (Continued)
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a lower
gear before starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.

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 (7,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-7
1.Engine Air Cleaner/Filter on
page 10-15.
2. Engine Cover.
3. Engine Cooling Fans (Out of View). See Cooling System on
page 10-17.
4. Engine Oil Fill Cap. See Engine
Oil on page 10-11.
5. Engine Oil Dipstick (Out of View). See Engine Oil on
page 10-11. 6. High Voltage Cable (Orange
Color).
7. Transmission Fluid Cap. See Automatic Transmission Fluid on
page 10-15.
8. Brake Master Cylinder Reservoir. See Brakes on
page 10-25.
9. Battery (Under Cover). See Battery on page 10-27. 10. Coolant Surge Tank and
Pressure Cap. See Engine
Coolant on page 10-19.
11. Engine Compartment Fuse
Block on page 10-36.
12. Windshield Washer Fluid Reservoir. See Washer Fluid
on page 10-24.

Black plate (9,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-9
1.Engine Air Cleaner/Filter on
page 10-15.
2. Power Steering Reservoir and Cap. See Power Steering Fluid
(2.4L L4 Engine and 3.6L
V6 Engine with FWD) on
page 10-23 orPower Steering
Fluid (3.6L V6 Engine with AWD)
on page 10-23.
3. Engine Oil Fill Cap. See Engine
Oil on page 10-11.
4. Engine Oil Dipstick. See Engine
Oil on page 10-11. 5. Engine Cover.
6. Transmission Fluid Cap and
Dipstick. See Automatic
Transmission Fluid on
page 10-15.
7. Brake Master Cylinder Reservoir. See Brakes on
page 10-25.
8. Coolant Surge Tank and Pressure Cap. See Engine
Coolant on page 10-19. 9. Battery Cover. See
Battery on
page 10-27.
10. Engine Compartment Fuse
Block on page 10-36.
11. Windshield Washer Fluid Reservoir. See Washer Fluid
on page 10-24.

Black plate (11,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-11
1.Engine Air Cleaner/Filter on
page 10-15.
2. Engine Oil Fill Cap. See Engine
Oil on page 10-11.
3. Engine Oil Dipstick. See Engine
Oil on page 10-11.
4. Engine Cover.
5. Transmission Fluid Cap and Dipstick. See Automatic
Transmission Fluid on
page 10-15.
6. Brake Master Cylinder Reservoir. See Brakes on
page 10-25.
7. Coolant Surge Tank and Pressure Cap. See Engine
Coolant on page 10-19.
8. Battery Cover. See Battery on
page 10-27.
9. Engine Compartment Fuse
Block on page 10-36.
10. Windshield Washer Fluid Reservoir. See Washer Fluid
on page 10-24.Engine Oil
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
.Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
.Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10-13.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Checking Engine Oil
It is a good idea to check the engine
oil level at each fuel fill. In order to
get an accurate reading, the vehicle
must be on level ground. The
engine oil dipstick handle is a loop.
SeeEngine Compartment Overview
on page 10-6 for the location of the
engine oil dipstick.
Obtaining an accurate oil level
reading is essential:
1. If the engine has been running recently, turn off the engine and
allow several minutes for the oil
to drain back into the oil pan.
Checking the oil level too soon
after engine shutoff will not
provide an accurate oil level
reading.
{Warning
The engine oil dipstick handle
may be hot; it could burn you.
Use a towel or glove to touch the
dipstick handle.

Black plate (15,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-15
Automatic Transmission
Fluid
How to Check Automatic
Transmission Fluid
It is not necessary to check the
transmission fluid level.
A transmission fluid leak is the only
reason for fluid loss. If a leak
occurs, take the vehicle to your
dealer service department and have
it repaired as soon as possible.
There is a special procedure for
checking and changing the
transmission fluid. Because this
procedure is difficult, you should
have this done at your dealer
service department. Contact your
dealer for additional information or
the procedure can be found in the
service manual. To purchase a
service manual, seeService
Publications Ordering Information
on page 13-11. Change the fluid at the intervals
listed in
Maintenance Schedule on
page 11-2, and be sure to use the
fluid listed in Recommended Fluids
and Lubricants on page 11-12.Engine Air Cleaner/Filter
The engine air cleaner/filter is in the
engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview on
page 10-6.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at the
scheduled maintenance intervals
and replace it at the first oil change
after each 80 000 km (50,000 mi)
interval. See Maintenance Schedule
on page 11-2. If you are driving in
dusty/dirty conditions, inspect the
filter at each engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter,
remove the filter from the vehicle
and lightly shake the filter to release
loose dust and dirt. If the filter
remains covered with dirt, a new
filter is required.
2.4L L4 Engine
1. Screws
2. Air Duct Clamp
3. Electrical Connector

Black plate (29,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-29
Automatic Transmission
Shift Lock Control
Function Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Apply the parking brake. Be ready to apply the regular brake
immediately if the vehicle begins
to move. 3. With the engine off, turn the
ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
Ignition Transmission
Lock Check
If equipped with a key type ignition,
while parked and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park).
.The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.

Black plate (37,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Vehicle Care 10-37
J-CaseFuses Usage
25 Rear Heated Seats
26 Antilock Brake System Pump
27 Electric Parking Brake
28 Rear Window Defogger
41 Brake Vacuum Pump
42 Cooling Fan K2
43 Not Used
44 Transmission Auxiliary Oil Pump
(eAssist)
45 Cooling Fan K1
59 AIR Pump Mini Fuses Usage
1 Transmission Control Module —
Battery
2 Engine Control Module Battery
3 Air Conditioning Compressor Clutch
5 Engine Control Module Run/Crank
7 Long Range Radar/ Front Camera
8 Ignition Coils –Even
(Six Cylinder
Engine), Ignition
Coils –All (Four
Cylinder Engine)
9 Ignition Coils –Odd
(Six Cylinder
Engine) Mini Fuses Usage
10 Engine Control Module–Switched
Battery (from Engine
Control Module
Relay)
11 Six Cylinder Engine: Post Catalytic
Converter Oxygen
Sensor Heater,
Mass Air Flow
Sensor, FlexFuel
Sensor, Secondary
Air Induction
Solenoid
13 Crank for Transmission
Control Module/Fuel
Pump Power/
Chassis Control
Module (eAssist)