
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 (15,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-15
Caution (Continued)
breaking-in guideline every
time you get new brake
linings.
Following break-in, engine speed
and load can be gradually
increased.
Ignition Positions (Key
Access)
{Caution
Using a tool to force the key to
turn in the ignition could cause
damage to the switch or break the
key. Use the correct key, make
sure it is all the way in, and turn it
only with your hand. If the key
cannot be turned by hand, see
your dealer.
The key must be fully extended to
start the vehicle.
To shift out of P (Park), turn the
ignition to ON/RUN and apply the
brake pedal.
1 (STOPPING THE ENGINE/LOCK/
OFF): When the vehicle is stopped,
turn the ignition switch to LOCK/
OFF to turn the engine off. Retained
Accessory Power (RAP) will remain
active. See Retained Accessory
Power (RAP) on page 9-23 for more
information. This is the only position from which
the key can be removed. This locks
the ignition and automatic
transmission.
Do not turn the engine off when the
vehicle is moving. This will cause a
loss of power assist in the brake
and steering systems and disable
the airbags.
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steady
pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral). This can be done while the
vehicle is moving. After shifting
to N (Neutral), firmly apply the
brakes and steer the vehicle to a
safe location.
3. Come to a complete stop, shift to P (Park), and turn the ignition
to LOCK/OFF. On vehicles with
an automatic transmission, the

Black plate (17,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-17
Pressing the button cycles it through
three modes, ACC/ACCESSORY,
ON/RUN/START, and Stopping the
Engine/OFF.
The transmitter must be in the
vehicle for the system to operate.
If the pushbutton start is not
working, the vehicle may be near a
strong radio antenna signal causing
interference to the keyless access
system. SeeRemote Keyless Entry
(RKE) System Operation on
page 2-3.
To shift out of P (Park), the vehicle
must be in ACC/ACCESSORY or
ON/RUN and the brake pedal must
be applied.
Stopping the Engine/OFF (No
Indicator Lights): When the
vehicle is stopped, press the
ENGINE START/STOP button once
to turn the engine off.
If the vehicle is in P (Park), the
ignition will turn off, and Retained
Accessory Power (RAP) will remain
active. See Retained Accessory
Power (RAP) on page 9-23. If the vehicle is not in P (Park), the
ignition will return to ACC/
ACCESSORY and display the
message SHIFT TO PARK in the
Driver Information Center (DIC).
See
Transmission Messages on
page 5-44. When the vehicle is
shifted into P (Park), the ignition
system will switch to OFF.
Do not turn the engine off when the
vehicle is moving. This will cause a
loss of power assist in the brake
and steering systems and disable
the airbags.
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steady pressure. Do not pump the
brakes repeatedly. This may
deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral). This can be done while the
vehicle is moving. After shifting
to N (Neutral), firmly apply the
brakes and steer the vehicle to a
safe location. 3. Come to a complete stop, shift
to P (Park), and turn the ignition
to OFF. On vehicles with an
automatic transmission, the shift
lever must be in P (Park) to turn
the ignition switch to the OFF
position.
4. Set the parking brake. See Parking Brake on page 9-31.
{Warning
Turning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, only shut the
vehicle off in an emergency.
If the vehicle cannot be pulled over,
and must be shut off while driving,
press and hold the ENGINE START/
STOP button for longer than
two seconds, or press twice in
five seconds.

Black plate (20,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-20 Driving and Operating
If the RKE transmitter is not in
the vehicle, if there is
interference, or the RKE battery
is low, the Driver Information
Center (DIC) will display a
message. SeeKey and Lock
Messages on page 5-39 and
Remote Keyless Entry (RKE)
System Operation on page 2-3.
{Caution
Cranking the engine for long
periods of time, by returning the
ignition to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down.
2. If the engine does not start after five to 10 seconds, especially in
very cold weather (below −18°C
or 0°F), it could be flooded with
too much gasoline. Try pushing
the accelerator pedal all the way to the floor and holding it there
as you press the ENGINE
START/STOP button, for up to a
maximum of 15 seconds. Wait at
least 15 seconds between each
try, to allow the cranking motor
to cool down. When the engine
starts, let go of the button, and
the accelerator. If the vehicle
starts briefly but then stops
again, do the same thing. This
clears the extra gasoline from
the engine. Do not race the
engine immediately after starting
it. Operate the engine and
transmission gently until the oil
warms up and lubricates all
moving parts.
eAssist Automatic Engine
Start/Stop
{Warning
Exiting the vehicle without first
shifting into P (Park) may cause
the vehicle to move. You or others
(Continued)
Warning (Continued)
may be injured. Because the
vehicle has the automatic engine
start/stop feature, the vehicle's
engine might seem to be shut off;
however, once the brake pedal is
released, the engine will start up
again.
Shift to P (Park) and turn the
ignition to LOCK/OFF, before
exiting the vehicle.
Vehicles with eAssist have an
automatic engine start/stop feature.
After the engine is started and has
reached operating temperature, the
auto stop feature may cause the
engine to turn off when the brakes
are applied and the vehicle comes
to a complete stop. The vehicle may
remain in auto stop for up to
two minutes. When the brake is
released or the accelerator pedal
applied, the engine will start. The
engine will continue to run until the
next auto stop.

Black plate (21,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-21
AUTO STOP on the tachometer
signifies that the engine is in auto
stop mode. SeeTachometer on
page 5-11. When the vehicle is
turned off, the tachometer will move
to OFF. If the driver door is opened
while in auto stop mode, a chime
will sound.
To restart the engine during auto
stop, release the brake pedal or
press the accelerator pedal. The
engine starts immediately. The
vehicle continues to run until the
next stop.
There are several conditions that
may prevent an auto stop or cause
an auto start.
The Engine Will Remain
Running When:
.The engine, transmission,
or high voltage battery is not
warmed up yet.
.The outside temperature is less
than −20°C (−4°F).
.The air conditioning or defrost
system need the compressor to
maintain interior comfort. See
Dual Automatic Climate Control
System on page 8-1 When it is
very warm or humid, the system
may not be able to shut the
engine off while maintaining
interior comfort. To maximize
fuel economy, use the eco air
conditioning mode.
.The shift lever is in P (Park),
N (Neutral), R (Reverse),
or M (Manual Mode).
.The high voltage battery pack
charge is low.
.The hood is not fully closed.
.Brake pedal pressure is low.
.If the malfunction indicator lamp
is on, auto stop may be
prevented.
.High humidity is detected.
The Engine Will Restart When:
.The brake pedal is released.
.The accelerator pedal is applied.
.Shifting out of D (Drive) to any
other gear.
.The air conditioning or defrost
system need the compressor to
maintain interior comfort. See
Dual Automatic Climate Control
System on page 8-1. The
warmer it is outside, the shorter
the time before the engine is
restarted to provide interior
cooling. To maximize fuel
economy, use the eco air
conditioning mode.
.The climate control system is
turned from off to normal air
conditioning or defrost. See Dual
Automatic Climate Control
System on page 8-1.
.The engine is required to run for
either heater or climate control
performance. See Dual
Automatic Climate Control
System on page 8-1.
.The high voltage battery pack
charge is low and requires
recharging.

Black plate (22,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-22 Driving and Operating
.Auto stop time is greater than
two minutes.
.The hood is opened.
Engine Heater
The engine coolant heater,
if available, can help in cold weather
conditions at or below−18°C (0°F)
for easier starting and better fuel
economy during engine warm-up.
Plug in the coolant heater at least
four hours before starting the
vehicle. An internal thermostat in
the plug end of the cord will prevent
engine coolant heater operation at
temperatures above −18°C (0°F).
To Use the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord.
3.6L V6 Engine
The electrical cord is located on
the driver side of the engine
compartment, between the
fender and the engine
compartment fuse block on
vehicles with a six cylinder
engine.2.4L L4 Engine
The electrical cord is located on
the passenger side of the engine
compartment, between the
fender and the air cleaner on
vehicles with a four cylinder
engine.
Check the heater cord for
damage. If it is damaged, do not
use it. See your dealer for a
replacement. Inspect the cord for
damage yearly.
3. Plug it into a normal, grounded 110-volt AC outlet.

Black plate (27,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-27
Automatic
Transmission
Shift Lever without Selective RideControl Shown
P (Park): This position locks the
front wheels. It is the best position
to use when starting the engine
because the vehicle cannot move
easily.
{Warning
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running. If you have left
the engine running, the vehicle
can move suddenly. You or others
could be injured. To be sure the
vehicle will not move, even when
you are on fairly level ground,
always set the parking brake and
move the shift lever to P (Park).
See Shifting Into Park on
page 9-24 andDriving
Characteristics and Towing Tips
on page 9-63.
Make sure the shift lever is fully in
P (Park) before starting the engine.
The vehicle has an automatic
transmission shift lock control
system. The regular brake must be
fully applied first and then the shift lever button pressed before shifting
from P (Park) when the ignition key
is in ON/RUN. If you cannot shift out
of P (Park), ease pressure on the
shift lever, then push the shift lever
all the way into P (Park) as you
maintain brake application. Then
press the shift lever button and
move the shift lever into another
gear. See
Shifting out of Park on
page 9-25.
R (Reverse): Use this gear to
back up.
{Caution
Shifting to R (Reverse) while the
vehicle is moving forward could
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Shift to
R (Reverse) only after the vehicle
is stopped.

Black plate (30,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-30 Driving and Operating
engine rpm is too high, nor to the
next higher gear when the maximum
engine rpm is reached.
While in Manual Mode, the
transmission will automatically
downshift when the vehicle comes
to a stop. This will allow for more
power during take-off.
When accelerating the vehicle from
a stop in snowy and icy conditions,
you may want to shift into
2 (Second) gear. A higher gear
allows the vehicle to gain more
traction on slippery surfaces.Drive Systems
All-Wheel Drive
Vehicles with this feature always
send engine power to all four
wheels. It is fully automatic, and
adjusts itself as needed for road
conditions.
All-Wheel Drive (AWD) system
performance will be automatically
reduced when the compact spare
tire is in use. To restore full AWD
performance, and prevent excessive
wear to the AWD system, replace
the compact spare tire with a
full-size tire as soon as possible.
SeeCompact Spare Tire on
page 10-77.
Brakes
Antilock Brake
System (ABS)
This vehicle has ABS, an advanced
electronic braking system that helps
prevent a braking skid.
When the vehicle begins to drive
away, ABS checks itself.
A momentary motor or clicking noise
might be heard while this test is
going on, and it might even be
noticed that the brake pedal moves
a little. This is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
on page 5-20.