
Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
118 Instruments and Controls
If the light is flashing :A
malfunction has been detected that
could damage the emission control
system and increase vehicle
emissions. Diagnosis and service
may be required.
To help prevent damage, reduce
vehicle speed and avoid hard
accelerations and uphill grades.
If towing a trailer, reduce the
amount of cargo being hauled as
soon as possible.
If the light continues to flash, find a
safe place to park. Turn the vehicle
off and wait at least 10 seconds
before restarting the engine. If the
light is still flashing, follow the
previous guidelines and see your
dealer for service as soon as
possible.
If the light is on steady : A
malfunction has been detected.
Diagnosis and service may be
required.
Check the following:
. If fuel has been added to the
vehicle using the capless funnel
adapter, make sure that it has been removed. See
“Filling the
Tank with a Portable Gas Can”
under Filling the Tank 0219.
The diagnostic system can
detect if the adapter has been
left installed in the vehicle,
allowing fuel to evaporate into
the atmosphere. A few driving
trips with the adapter removed
may turn off the light.
. Poor fuel quality can cause
inefficient engine operation and
poor driveability, which may go
away once the engine is warmed
up. If this occurs, change the
fuel brand. It may require at
least one full tank of the proper
fuel to turn the light off. See Fuel
0 218.
If the light remains on, see your
dealer.
Emissions Inspection and
Maintenance Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the
test equipment will likely connect to
the vehicle's Data Link
Connector (DLC).
The DLC is under the instrument
panel to the left of the steering
wheel. Connecting devices that are
not used to perform an Emissions
Inspection/Maintenance test or to
service the vehicle may affect
vehicle operation. See Add-On
Electrical Equipment 0226. See
your dealer if assistance is needed.
The vehicle may not pass
inspection if:
. The light is on when the engine
is running.
. The light does not come on
when the ignition is on with the
engine not running for Key
Access or in Service Mode for
Keyless Access.
. Critical emission control systems
have not been completely
diagnosed. If this happens, the
vehicle would not be ready for

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Climate Controls 153
10. AUTO (Automatic Operation)
Climate Control Display
1. Outside Temperature Display
2. Driver and Passenger Temperature Controls
3. Fan Control
4. Sync (Synchronized Temperature)
5. A/C (Air Conditioning)
6. Climate Control Selection (Application Tray Control)
7. Air Delivery Mode Control The fan, air delivery mode, air
conditioning, driver and passenger
temperatures, and Sync settings
can be controlled by touching
CLIMATE on the infotainment Home
Page or the climate button in the
climate display application tray.
A selection can then be made on
the front climate control page
displayed. See the infotainment
manual.
Climate Control Status Display
The climate control status display
appears briefly when the center
stack climate controls are adjusted. The air delivery mode can be
adjusted on the climate control
display.
Climate Control Influence on
eAssist Operation and Fuel
Economy (If Equipped)
The climate control system depends
on other vehicle systems for heat
and power input. Certain climate
control settings can lead to higher
fuel usage and/or fewer Auto Stops.
The following climate control
settings use more fuel:
.
MAX air conditioning mode
. Defrost mode
. Extreme temperature settings,
such as 15° C (60° F) or 32° C
(90° F)
. High fan speed settings
To help reduce fuel usage:
. Use the full automatic control as
described under “Automatic
Operation.”
. Select a temperature setting that
is higher in hot weather and
lower in cold weather.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Climate Controls 155
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 (Air Conditioning) :
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. Auto Stops
will occur less frequently, be shorter,
and will not occur in extremely warm
weather.
For ECO a/c, touch A/C again. This
setting balances fuel economy and
air conditioning comfort. In warm
weather conditions, Auto Stops may
occur more frequently, last longer,
and the vehicle interior may be
warmer during Auto Stops as
compared to the MAX A/C setting.
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.
If equipped, the Air Quality Sensor
may operate the recirculation mode
automatically. See “Climate and Air
Quality” underVehicle
Personalization 0133.
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

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 159
Driving and
Operating
Driving Information
Distracted Driving . . . . . . . . . . . . 160
Defensive Driving . . . . . . . . . . . . . 161
Drunk Driving . . . . . . . . . . . . . . . . . 161
Control of a Vehicle . . . . . . . . . . . 161
Braking . . . . . . . . . . . . . . . . . . . . . . . 161
Steering . . . . . . . . . . . . . . . . . . . . . . 162
Off-Road Recovery . . . . . . . . . . . 162
Loss of Control . . . . . . . . . . . . . . . 163
Driving on Wet Roads . . . . . . . . 163
Hill and Mountain Roads . . . . . 164
Winter Driving . . . . . . . . . . . . . . . . 165
If the Vehicle Is Stuck . . . . . . . . 166
Vehicle Load Limits . . . . . . . . . . . 166
Starting and Operating
New Vehicle Break-In . . . . . . . . . 170
Ignition Positions . . . . . . . . . . . . . 170
Starting the Engine . . . . . . . . . . . 172
Engine Heater . . . . . . . . . . . . . . . . 175
Retained AccessoryPower (RAP) . . . . . . . . . . . . . . . . 176
Shifting Into Park . . . . . . . . . . . . . 176
Shifting out of Park . . . . . . . . . . . 177
Parking over Things That Burn . . . . . . . . . . . . . . . . . . . 179 Extended Parking . . . . . . . . . . . . 179
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . 180
Running the Vehicle While
Parked . . . . . . . . . . . . . . . . . . . . . . 180
Automatic Transmission
Automatic Transmission . . . . . . 181
Manual Mode . . . . . . . . . . . . . . . . . 185
Drive Systems
All-Wheel Drive . . . . . . . . . . . . . . . 187
Brakes
Antilock BrakeSystem (ABS) . . . . . . . . . . . . . . . 187
Electric Parking Brake . . . . . . . . 188
Brake Assist . . . . . . . . . . . . . . . . . . 189
Automatic Vehicle Hold (AVH) . . . . . . . . . . . . . . . . . . 189
Ride Control Systems
Traction Control/ElectronicStability Control . . . . . . . . . . . . . 190
Selective Ride Control . . . . . . . . 192
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . 193
Adaptive Cruise Control . . . . . . 195
Driver Assistance Systems
Driver Assistance Systems . . . 203 Assistance Systems for
Parking or Backing . . . . . . . . . . 204
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . . 207
Forward Collision Alert (FCA)
System . . . . . . . . . . . . . . . . . . . . . . 208
Forward Automatic Braking (FAB) . . . . . . . . . . . . . . . 210
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . 211
Side Blind Zone Alert (SBZA) . . . . . . . . . . . . . . . . 213
Lane Change Alert (LCA) . . . . . 214
Lane Departure Warning (LDW) . . . . . . . . . . . . . 215
Lane Keep Assist (LKA) . . . . . . 216
Fuel
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 218
California Fuel Requirements . . . . . . . . . . . . . . . 218
Fuels in Foreign Countries . . . 219
Fuel Additives . . . . . . . . . . . . . . . . 219
Filling the Tank . . . . . . . . . . . . . . . 219
Filling a Portable Fuel Container . . . . . . . . . . . . . . . . . . . 220
Trailer Towing
General TowingInformation . . . . . . . . . . . . . . . . . . 221

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 171
Warning (Continued)
systems and disable the airbags.
While driving, only shut the
vehicle off in an emergency.
If the ignition 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 press ENGINE
START/STOP.
4. Set the parking brake. See Electric Parking Brake 0188. If the vehicle cannot be pulled over
and must be shut off while driving,
press and hold ENGINE START/
STOP for longer than two seconds,
or press twice in five seconds.
ACC/ACCESSORY (Amber
Indicator Light) :
This mode allows
you to use some electrical
accessories when the ignition is off.
With the ignition off, pressing
ENGINE START/STOP once without
the brake pedal applied will place
the ignition system in ACC/
ACCESSORY.
The ignition will switch from ACC/
ACCESSORY to OFF after
10 minutes to prevent battery
rundown.
ON/RUN/START (Green Indicator
Light) : This mode is for driving and
starting. With the ignition off and the
brake pedal applied, pressing
ENGINE START/STOP once will
place the ignition system in ON/
RUN/START. Once engine cranking
begins, release the button. Engine
cranking will continue until the engine starts. See
Starting the
Engine 0172. The ignition will then
remain in ON/RUN.
Service Mode
This power mode is available for
service and diagnostics. See
Automatic Transmission 0181.
Service Mode is also available to
verify the proper operation of the
malfunction indicator lamp as may
be required for emission inspection
purposes. With the ignition off and
the brake pedal not applied,
pressing and holding ENGINE
START/STOP for more than
five seconds will place the vehicle in
Service Mode. The instruments and
audio systems will operate as they
do in ON/RUN, but the vehicle will
not be able to be driven. The engine
will not start in Service Mode. Press
ENGINE START/STOP again to turn
the vehicle off.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
Driving and Operating 173
starting it. Operate the engine
and transmission gently until
the oil warms up and lubricates
all moving parts.
Stop/Start System
{Warning
Exiting the vehicle without first
shifting into P (Park) may cause
the vehicle to move. You or others
may be injured. Because the
vehicle may have an auto engine
stop/start 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 off before exiting the
vehicle.
The vehicle may be equipped with a
fuel saving Stop/Start system to
shut off the engine to help
conserve fuel.
Auto Stop (Vehicles without
eAssist)
If equipped, when the brakes are
applied and the vehicle is at a
complete stop, the engine may turn
off. When stopped, the tachometer
displays AUTO STOP. See
Tachometer 0112. When the brake
pedal is released or the accelerator
pedal is pushed, the engine will
restart.
The vehicle may remain in Auto
Stop even after it is shifted into
P (Park). Auto Stop will be
maintained until the door is opened
or the seat belt is unbuckled. There are several conditions that
may prevent an Auto Stop or cause
an Auto Start.
Auto Stop may be deactivated if:
.
A minimum vehicle speed is not
reached.
. The engine or transmission is
not at the required operating
temperature.
. The outside temperature is not
in the required operating range,
typically below −10 °C (14 °F) or
above 50 °C (122 °F).
. The transmission is in any gear
other than D (Drive).
. The battery charge is low.
. The battery has been
disconnected.
. The system may not be able to
shut off the engine in order to
maintain the air conditioning
comfort level or defrost system
settings. See Dual Automatic
Climate Control System 0152.
To maximize fuel economy, use
the ECO air conditioning mode.

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
174 Driving and Operating
.The Auto Stop time is greater
than two minutes.
Auto Stop (Vehicles with
eAssist)
If equipped, when the brakes are
applied and the vehicle is at a
complete stop, the engine may turn
off. When stopped, the tachometer
displays AUTO STOP. See
Tachometer 0112. When the brake
pedal is released or the accelerator
pedal is pushed, 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.
There are several conditions that
may prevent an Auto Stop or cause
an Auto Start.
Auto Stop may be
deactivated when:
.
The engine, transmission,
or high voltage battery is not at
the required operating
temperature.
. The outside temperature is not
in the required operating range,
typically below −20 °C (−4 °F).
. The system may not be able to
shut off the engine in order to
maintain the air conditioning
comfort level or defrost system
settings. See Dual Automatic
Climate Control System 0152.
To maximize fuel economy, use
the ECO air conditioning mode. .
The transmission is in any gear
other than D (Drive).
. The high voltage battery charge
is low.
. The hood is not fully closed.
. The malfunction indicator lamp
is on.
. 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 besides P (Park).
. The air conditioning or defrost
system needs the compressor to
maintain interior comfort. See
Dual Automatic Climate Control
System 0152. To maximize fuel
economy, use the ECO air
conditioning mode.
. The engine is required to run for
either heater or climate control
performance, or the climate
control system is turned from off

Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada-10999169) -
2018 - crc - 3/28/17
186 Driving and Operating
To enter Permanent Tap Shift Mode:1. With the transmission in D (Drive), pull back on the shift
lever to activate M (Manual
Mode). The M in the shift
pattern will illuminate in red,
and the D will switch to white.
2. Tap the left steering wheel control to downshift, and the
right control to upshift. To shift
to the lowest available gear,
press and hold the left control.
3. To exit, pull back on the shift lever a second time. The D in
the shift pattern will illuminate
in red, and the M will switch to
white.
To enter Temporary Tap Shift Mode: 1. With transmission in D, Tap the left steering wheel control to
downshift, and the right control
to upshift. 2. To shift to the lowest available
gear, press and hold the left
control.
3. To deactivate, hold the right upshift control briefly.
After temporary tap shifts, automatic
shifts return after no manual shifts
have been done for seven to
10 seconds.
While using Tap Shift, the vehicle
will have firmer, quicker shifting.
This can be used for sport driving or
when climbing or descending hills,
to stay in gear longer, or to
downshift for more power or engine
braking.
The transmission will only allow
shifting into gears appropriate for
the vehicle speed and engine
revolutions per minute (rpm). The
transmission will not automatically
shift to the next lower gear if the
engine rpm is too high, nor to the
next higher gear when the maximum
engine rpm is reached. If shifting is prevented for any
reason, a SHIFT DENIED message
will be displayed in the instrument
cluster.
When accelerating the vehicle from
a stop in snowy and icy conditions,
it is suggested to shift into second
gear. A higher gear allows the
vehicle to gain more traction on
slippery surfaces.