towing BUICK LACROSSE 2015 User Guide

Black plate (33,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-33
Caution (Continued)
damage to brake system parts.
Make sure that the parking brake
is fully released and the brake
warning light is off before driving.
Automatic EPB Release
The EPB will automatically release if
the vehicle is running, placed into
gear, and an attempt is made to
drive away. Avoid rapid acceleration
when the EPB is applied, to
preserve parking brake lining life.
If parking on a hill, or if the vehicle
is pulling a trailer, seeDriving
Characteristics and Towing Tips on
page 9-63.
Brake Assist
The Brake Assist feature is
designed to assist the driver in
stopping or decreasing vehicle
speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake
control module to supplement the
power brake system under
conditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle. The
stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time is
normal and the driver should
continue to apply the brake pedal as
the driving situation dictates. The
Brake Assist feature will
automatically disengage when the
brake pedal is released or brake
pedal pressure is quickly
decreased.
Hill Start Assist (HSA)
This vehicle has an HSA feature,
which may be useful when the
vehicle is stopped on a grade
sufficient enough to activate HSA.
This feature is designed to prevent
the vehicle from rolling, either
forward or rearward, during vehicle
drive off. After the driver completely
stops and holds the vehicle in a
complete standstill on a grade, HSA
will be automatically activated.
During the transition period between
when the driver releases the brake
pedal and starts to accelerate to
drive off on a grade, HSA holds the
braking pressure for a maximum of
two seconds to ensure that there is
no rolling. The brakes will
automatically release when the
accelerator pedal is applied within
the two-second window. It will not
activate if the vehicle is in a drive
gear and facing downhill, or if the
vehicle is facing uphill and in
R (Reverse).

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 (49,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-49
1. View Displayed by theCamera
2. Corners of the Rear Bumper
Displayed images may be farther or
closer than they appear. The area
displayed is limited and objects that
are close to either corner of the
bumper or under the bumper do not
display.
A warning triangle may display on
the RVC screen to show where the
Rear Parking Assist (RPA) has
detected an object. This triangle
changes from amber to red and
increases in size the closer the
object. On vehicles with the Rear Cross
Traffic Alert (RCTA), a triangle with
an arrow may also display on the
RVC screen to warn of traffic
coming from either direction when
backing. This system detects
objects coming from up to 20 m
(66 ft) from the left or right side
behind the vehicle. When an object
is detected, either three beeps
sound from the left or right side or
three Safety Alert Seat pulses occur
on the left or right side, depending
on the direction of the detected
vehicle.
Use caution while backing up when
towing a trailer, as the RCTA
detection zones that extend out
from the back of the vehicle do not
move further back when a trailer is
towed.
With RPA, as the vehicle backs up
at speeds of less than 8 km/h
(5 mph), the sensors on the rear
bumper detect objects up to 2.5 m
(8 ft) behind the vehicle that are
within a zone 25 cm (10 in) high off
the ground and below bumper level.These detection distances may be
shorter during warmer or humid
weather. Blocked sensors will not
detect objects and can also cause
false detections. Keep the sensors
clean of mud, dirt, snow, ice, and
slush; and clean sensors after a car
wash in freezing temperatures.
{Warning
The parking assist system does
not detect children, pedestrians,
bicyclists, animals, or objects
located below the bumper or that
are too close or too far from the
vehicle. It is not available at
speeds greater than 8 km/h
(5 mph). To prevent injury, death,
or vehicle damage, even with
parking assist, always check the
area around the vehicle and
check all mirrors before moving
forward or backing.

Black plate (50,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-50 Driving and Operating
The vehicle may have instrument
cluster parking assist display with
bars that show“distance to object”
and object location information for
RPA. As the object gets closer,
more bars light up and the bars
change color from yellow to amber
to red.
When an object is first detected,
one beep will be heard from the
rear, or both sides of the Safety
Alert Seat will pulse two times.
When an object is very close
(<0.6 m (2 ft)), five beeps will sound,
or both sides of the Safety Alert
Seat will pulse five times.
Turning the Features On or Off
TheXbutton on the center stack
is used to turn on or off the Rear
Parking Assist. The indicator light
next to the button comes on when
the feature is on and turns off when
the feature has been disabled.
Turn off parking assist when towing
a trailer.
The parking assist symbols and
guidance lines can be turned on or
off through the Settings menu on
the infotainment system:
1. On the infotainment system, press the Settings screen
button, or turn the MENU knob
to highlight Settings and
press MENU.
2. Select Rear Camera. 3. Press Rear Park Assist Symbols
or Guidance Lines, and then
select OFF or ON.
Assistance Systems for
Driving
If equipped, when driving the
vehicle forward, Forward Collision
Alert (FCA), Lane Departure
Warning (LDW), Side Blind Zone
Alert (SBZA), Lane Change Alert
(LCA), and/or the Active Emergency
Braking System can help to avoid a
crash or reduce crash damage.
Forward Collision Alert
(FCA) System
The FCA system may help to avoid
or reduce the harm caused by
front-end crashes. FCA provides a
flashing red alert on the windshield,
and beeps or pulses the Safety Alert
Seat when approaching a vehicle
directly ahead too quickly. FCA also
provides a visual alert if following
another vehicle much too closely.

Black plate (54,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-54 Driving and Operating
Warning (Continued)
Complete attention is always
required while driving, and you
should be ready to take action
and apply the brakes and/or steer
the vehicle to avoid crashes.
Brake Preparation
When quickly approaching a vehicle
ahead, Brake Preparation reduces
brake response time by having the
brake system prepared for driver
braking to occur more rapidly.
Automatic Braking
If ACP detects it is about to crash
with the vehicle you are following
that is moving or has come to a
stop, and the brakes have not been
applied, it may automatically brake
hard. This can help to reduce crash
damage and it may even help to
avoid some very low speed crashes. Automatic Braking may slow the
vehicle to a complete stop to try to
avoid a potential crash. The vehicle
will only hold at a stop briefly. A firm
press of the accelerator pedal will
also release Automatic Braking.
{Warning
Automatic Braking may
automatically brake the vehicle
suddenly in situations where it is
unexpected and undesired.
It could respond to a turning
vehicle ahead, guardrails, signs,
and other non-moving objects. To
override Automatic Braking, firmly
press the accelerator pedal, if it is
safe to do so.
Automatic Braking can be disabled
or reduced through vehicle
personalization. See the “Auto
Collision Preparation” portion of
“Collision/Detection Systems” under
Vehicle Personalization on
page 5-45.
{Warning
Using the Automatic Collision
Preparation System while towing
a trailer could cause you to lose
control of the vehicle and crash.
Turn the system off when towing
a trailer.
Side Blind Zone
Alert (SBZA)
If equipped, the SBZA system is a
lane-changing aid that assists
drivers with avoiding crashes that
occur with vehicles in the side blind
zone (or spot) areas. When the
vehicle is moving forward, the left or
right side mirror display will light up
if a vehicle is detected in that blind
zone. If the turn signal is activated
and a vehicle is also detected on
the same side, the display will flash
as an extra warning not to change
lanes. Since this system is part of

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 (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 (66,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-66 Driving and Operating
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing (Except
eAssist)
Before pulling a trailer, three
important considerations have to do
with weight:
.Weight of the trailer.
.Weight of the trailer tongue.
.Total weight on your vehicle's
tires.
Weight of the Trailer
How heavy can a trailer safely be?
It should never weigh more than
454 kg (1,000 lb). But even that can
be too heavy.
It depends on how the rig is used.
For example, speed, altitude, road
grades, outside temperature, andhow much the vehicle is used to pull
a trailer are all important. It can
depend on any special equipment
on the vehicle, and the amount of
tongue weight the vehicle can carry.
See
“Weight of the Trailer Tongue”
later in this section.
Maximum trailer weight is calculated
assuming only the driver is in the
tow vehicle and it has all the
required trailering equipment. The
weight of additional optional
equipment, passengers, and cargo
in the tow vehicle must be
subtracted from the maximum trailer
weight.
Ask your dealer for trailering
information or advice, or write us at
our Customer Assistance Offices.
See Customer Assistance Offices
on page 13-3.
Weight of the Trailer Tongue
The tongue load (1) of any trailer is
an important weight to measure
because it affects the total gross
weight of the vehicle. The Gross
Vehicle Weight (GVW) includes the curb weight of the vehicle, any
cargo carried in it, and the people
who will be riding in the vehicle.
If there are a lot of options,
equipment, passengers, or cargo in
the vehicle, it will reduce the tongue
weight the vehicle can carry, which
will also reduce the trailer weight the
vehicle can tow. If towing a trailer,
the tongue load must be added to
the GVW because the vehicle will
be carrying that weight, too. See
Vehicle Load Limits on page 9-10.