
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
160 Climate Controls
control and the direction of the
airflow is controlled manually. Press
AUTO to return to automatic
operation.
To change the current mode, select
one or more of the following:
6:Air is directed to the floor
outlets, with some air to the
windshield and side windows.
Y: Air is directed to the instrument
panel outlets.
X: Clears the windows of fog or
moisture. Air is directed to the
windshield.
1MAX : Air is directed to the
windshield, the fan runs at a higher
speed, and the temperature of the
air is increased if not already at
maximum. This mode overrides the
previous mode selected and clears
fog or frost from the windshield
more quickly. When the control is
pressed again, the system returns
to the previous mode setting and
fan speed. 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 :
Touch A/C on the climate
control display to cycle between the
MAX, ECO, and OFF modes. The
MAX, ECO, or OFF indicator will
appear on the display. If the fan is
turned off, the air conditioner will not
run and the indicator light will
turn off.
Touch AUTO to return to automatic
operation and the air conditioner
runs automatically as needed. The
A/C will return to ECO A/C
operation.
For MAX A/C, touch A/C.
For ECO A/C, touch A/C again. This
setting balances fuel economy and
air conditioning comfort. This setting allows higher humidity inside the
vehicle, and window fogging may
occur before the engine restarts.
@:
Press to turn on recirculation.
An indicator light comes on. Air is
recirculated to quickly cool the
inside of the vehicle or to reduce the
entry of outside air and odors.
If selected during cool or cold
weather, the windshield and
windows may fog. Turn off
recirculation to help clear the
windshield and windows.
Auto Defog : If equipped, 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.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Climate Controls 161
To turn Auto Defog off or on, see
“Climate and Air Quality”under
Vehicle Personalization 0138.
Ionizer : If equipped with an ionizer,
this feature helps to clean the air
inside the vehicle and remove
contaminants such as pollen, odors,
and dust. If the climate control
system is on and the ionizer is
enabled, the ionizer status indicator
will be lit on the climate control
display. To turn the ionizer on or off,
see “Climate and Air Quality” under
Vehicle Personalization 0138.
Rear Window Defogger
K:Press to turn the rear window
defogger on or off. An indicator light
on the control comes on to show
that the rear window defogger is on.
The rear window defogger only
works when the engine is running.
It turns off when the ignition is
turned off or in ACC/ACCESSORY.
The rear window defogger can be
set to automatic operation. See
“Climate and Air Quality” under
Vehicle Personalization 0138.
When Auto Rear Defog is selected, the rear window defogger turns on
automatically when the interior
temperature is cold and the outside
temperature is about 4 °C (40 °F)
and below. The auto rear defogger
turns off automatically after about
10 minutes, or after five minutes if
the outside temperature is not
as cold.
For eAssist vehicles, auto rear
defog will only run during a remote
start and the feature is not available
in the Vehicle Personalization menu.
The upper gridlines on the rear
window are antenna lines and are
not intended to heat when the
defogger is activated.
The heated outside mirrors turn on
when the rear window defogger
control is on and help to clear fog or
frost from the surface of the mirror.
See
Heated Mirrors 046.
Caution
Do not try to clear frost or other
material from the inside of the
front windshield and rear window
with a razor blade or anything
else that is sharp. This may
damage the rear window
defogger grid and affect the
radio's ability to pick up stations
clearly. The repairs would not be
covered by the vehicle warranty.
Heated and Ventilated Seats
MorL:If equipped, pressMorLto heat the driver or passenger seat.
Cor{:If equipped, pressCor{to ventilate the driver or
passenger seat. See Heated and
Ventilated Front Seats 059.
Remote Start Climate Control
Operation : The climate control
system may run when the vehicle is
started remotely. If equipped with
heated or ventilated seats, they may
come on during a remote start.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Climate Controls 163
Maintenance
Air Intake
Clear away any ice, snow, or leaves
from the air intake at the base of the
windshield that can block the flow of
air into the vehicle.
Passenger Compartment
Air Filter
The filter removes dust, pollen, and
other airborne irritants from outside
air that is pulled into the vehicle.
The filter should be replaced as part
of routine scheduled maintenance.
SeeMaintenance Schedule 0320
for replacement intervals. For more
information, see your dealer.
Service
All vehicles have a label underhood
that identifies the refrigerant used in
the vehicle. The refrigerant system
should only be serviced by trained
and certified technicians. The air
conditioning evaporator should
never be repaired or replaced by one from a salvage vehicle.
It should only be replaced by a new
evaporator to ensure proper and
safe operation.
During service, all refrigerants
should be reclaimed with proper
equipment. Venting refrigerants
directly to the atmosphere is harmful
to the environment and may also
create unsafe conditions based on
inhalation, combustion, frostbite,
or other health-based concerns.
The air conditioning system requires
periodic maintenance. See
Maintenance Schedule
0320.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
180 Driving and Operating
AUTO STOP. SeeTachometer
0 116. When the brake pedal is
released or the accelerator pedal is
pressed, the engine will restart.
The vehicle may remain in Auto
Stop for up to two minutes.
The vehicle may remain in Auto
Stop even after it is shifted into
P (Park). If the driver opens the door
or unbuckles the seat belt the
vehicle will exit Auto Stop and
restart the engine.
To maintain vehicle performance,
other conditions may cause the
engine to automatically restart
before the brake pedal is released.
Auto Stops may not occur and/or
auto restarts may occur because:
. The engine, transmission or high
voltage battery is not at the
required operating temperature.
. The outside temperature is not
in the required operating range.
. The climate control settings
require the engine to be running
to cool or heat the vehicle
interior. .
The vehicle is in any gear other
than D (Drive) or P (Park).
. The vehicle battery charge
is low.
. The hood has been opened.
. The malfunction indicator lamp
is on.
. High humidity is detected.
. The brake pedal is released.
. The accelerator pedal is
pressed.
. The driver door has been
opened or driver seat belt has
been unbuckled.
. The engine has not run for
sufficient time since the prior
Auto Stop.
Engine Heater
The engine 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
heater operation at temperatures
above
−18 °C (0 °F).
To Use the Engine Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord.
The electrical cord is on the
driver side of the engine
compartment, between the
fender and the engine
compartment fuse block.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Driving and Operating 195
Caution
Driving with the parking brake on
can overheat the brake system
and cause premature wear or
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.
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 underconditions 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)
The Hill Start Assist (HSA) feature
will activate when the vehicle is
stopped on a moderate to steep
grade to help prevent it from rolling
in an unintended direction. After the
brake pedal has been released and
before the accelerator pedal has
been pressed, HSA uses braking
pressure to hold the vehiclestationary. If HSA is holding the
vehicle, a Driver Information Center
(DIC) message displays. HSA will
not activate in a forward drive gear
when facing downhill, or in
R (Reverse) when facing uphill.
Select the duration of the HSA
feature through vehicle
personalization. See
”Extended Hill
Start Assist” under“Comfort and
Convenience” inVehicle
Personalization 0138. When
Standard Hold is selected, the
vehicle is held stationary for up to
two seconds after the brake pedal is
released. When Extended Hold is
selected, the vehicle is held
stationary for up to five minutes
after the brake pedal is released. In
either case, override the hold
feature by pressing the accelerator
pedal and attempting to drive away.
If Standard Hold is selected, it will
hold the vehicle for two seconds
unless the driver door is opened or
the driver seat belt is unbuckled
after releasing the brake pedal.
If Extended Hold is selected, it will
hold the vehicle for five minutes

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
196 Driving and Operating
unless the driver door is opened
and the driver seat belt is unbuckled
prior to releasing the brake pedal.
When deactivated after five minutes,
or if it is deactivated when the driver
seat belt is unlatched or the driver
door is opened, the Electric Parking
Brake will engage to prevent vehicle
movement.
Regenerative Braking
(eAssist)
Regenerative braking takes some of
the energy from the moving vehicle
and turns it back into electrical
energy. This energy is then stored
back into the high voltage battery
system, contributing to increased
energy efficiency.
The hydraulic disc brakes work with
the regenerative braking to ensure
effective braking, such as when a
high braking demand is requested.
The braking system is computer
controlled and blends the
regenerative braking with the
conventional hydraulic disc brakes
to meet any requirements fordeceleration. The controller
interprets the braking request and
uses regenerative braking,
conventional hydraulic braking, or a
combination of both as necessary.
Because the hydraulic braking
system uses an electronic booster
for boost assist on demand, under
certain conditions a motor noise
may be heard. This is normal
operation.
See
Warning Lights, Gauges, and
Indicators 0113 and Driver
Information Center (DIC) 0131. In
the event of a controller problem,
the brake pedal may be harder to
push and the stopping distance may
be longer.
Ride Control Systems
Traction Control/
Electronic Stability
Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak/
Electronic Stability Control (ESC).
These systems help limit wheel slip
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any
of the drive wheels are spinning or
beginning to lose traction. When this
happens, TCS applies the brakes to
the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak/ESC activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak/ESC selectively applies
braking pressure to any one of the

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
Driving and Operating 197
vehicle wheel brakes to assist the
driver in keeping the vehicle on the
intended path.
If cruise control is being used and
traction control or StabiliTrak/ESC
begins to limit wheel spin, cruise
control will disengage. Cruise
control may be turned back on when
road conditions allow.
Both systems come on
automatically when the vehicle is
started and begins to move. The
systems may be heard or felt while
they are operating or while
performing diagnostic checks. This
is normal and does not mean there
is a problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary
to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow.
SeeIf the Vehicle Is Stuck 0171
and “Turning the Systems Off and
On” later in this section.
The indicator light for both systems
is in the instrument cluster. This
light will:
.
Flash when TCS is limiting
wheel spin.
. Flash when StabiliTrak/ESC is
activated.
. Turn on and stay on when either
system is not working.
If either system fails to turn on or to
activate, a message displays in the
Driver Information Center (DIC), and
dcomes on and stays on to
indicate that the system is inactive
and is not assisting the driver in
maintaining control. The vehicle is
safe to drive, but driving should be
adjusted accordingly.
If
dcomes on and stays on:
1. Stop the vehicle. 2. Turn the engine off and wait
15 seconds.
3. Start the engine.
Drive the vehicle. If
dcomes on
and stays on, the vehicle may need
more time to diagnose the problem.
If the condition persists, see your
dealer.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-12032549) -
2019 - crc - 8/20/18
200 Driving and Operating
5:Press to turn cruise control on
or off. A white indicator comes on in
the instrument cluster.
RES+ : If there is a set speed in
memory, press the control up briefly
to resume to that speed or press
and hold to accelerate. If cruise
control is already engaged, use to
increase vehicle speed.
SET− :Press the control down
briefly to set the speed and activate
cruise control. If cruise control is
already engaged, use to decrease
vehicle speed.
*: Press to disengage cruise
control without erasing the set
speed from memory.
The speedometer reading can be
displayed in either English or metric
units. See Instrument Cluster 0114.
The increment value used depends
on the units displayed. Setting Cruise Control
If
5is on when not in use, SET−
or
RES+ could get pressed and go into
cruise when not desired. Keep
5
off when cruise is not being used.
1. Press
5to turn the cruise
system on.
2. Get to the speed desired.
3. Press and release SET− . The
desired set speed briefly
appears in the instrument
cluster.
4. Take your foot off the accelerator pedal.
The cruise control indicator on the
instrument cluster turns green after
the cruise control has been set to
the desired speed. See Instrument
Cluster 0114.
Resuming a Set Speed
If the cruise control is set at a
desired speed and then the brakes
are applied or
*is pressed, the
cruise control is disengaged without
erasing the set speed from memory. Once the vehicle reaches about
40 km/h (25 mph) or more, press
RES+ up briefly. The vehicle returns
to the previously set speed.
Increasing Speed While Using
Cruise Control
Do one of the following:
.
Press and hold RES+ up until
the vehicle accelerates to the
desired speed, then release it.
. To increase vehicle speed in
small increments, press RES+
up briefly. For each press, the
vehicle goes about 1 km/h
(1 mph) faster.
Reducing Speed While Using
Cruise Control
Do one of the following:
. Press and hold SET− down until
the desired lower speed is
reached, then release it.
. To slow down in small
increments, press SET− down
briefly. For each press, the
vehicle goes about 1 km/h
(1 mph) slower.