Page 201 of 407

Black plate (16,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-16 Driving and Operating
shift lever must be in P (Park) to
turn the ignition switch to the
LOCK/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,
turn the ignition to ACC/
ACCESSORY.
2 (ACC/ACCESSORY): This
position provides power to some of
the electrical accessories. It unlocks
the ignition. To move the key from
ACC/ACCESSORY to LOCK/OFF,
the shift lever must be in P (Park). 3 (ON/RUN):
The ignition switch
stays in this position when the
engine is running. This position can
be used to operate the electrical
accessories, including the
ventilation fan and 12-volt power
outlet, as well as to display some
warning and indicator lights. This
position can also be used for
service and diagnostics, and to
verify the proper operation of the
malfunction indicator lamp as may
be required for emission inspection
purposes. The transmission is also
unlocked in this position.
The battery could be drained if the
key is left in the ACC/ACCESSORY
or ON/RUN position with the engine
off. The vehicle might not restart if
the battery is allowed to drain for an
extended period of time.
4 (START): This position starts the
engine. When the engine starts,
release the key. The ignition switch
will return to ON/RUN for normal
driving. A warning tone sounds when the
driver door is opened when the
ignition is still in ACC/ACCESSORY
and the key is in the ignition. If the
ignition becomes difficult to turn,
see
Keys on page 2-1.
Ignition Positions
(Keyless Access)
The vehicle has an electronic
keyless ignition with pushbutton
start.
Page 202 of 407

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.
Page 203 of 407

Black plate (18,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
9-18 Driving and Operating
ACC/ACCESSORY (Amber
Indicator Light):This mode allows
you to use some electrical
accessories when the engine is off.
With the ignition off, pressing the
button one time without the brake
pedal applied will place the ignition
system in ACC/ACCESSORY.
The ignition will switch from ACC/
ACCESSORY to OFF after
five 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
the button 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 on
page 9-18. The ignition will then
remain in ON/RUN. Service Only Mode
This power mode is available for
service and diagnostics, and to
verify the proper operation of the
malfunction indicator lamp as may
be required for emission inspection
purposes. With the vehicle off, and
the brake pedal not applied,
pressing and holding the button for
more than five seconds will place
the vehicle in Service Only 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 Only Mode. Push the button
again to turn the vehicle off.
Starting the Engine
Move the shift lever to P (Park) or
N (Neutral). To restart the engine
when the vehicle is already moving,
use N (Neutral) only.
{Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.
{Caution
If you add electrical parts or
accessories, you could change
the way the engine operates. Any
resulting damage would not be
covered by the vehicle warranty.
See
Add-On Electrical Equipment
on page 9-68.
Page 204 of 407

Black plate (19,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-19
{Caution
If the steering wheel is turned
until it reaches the end of its
travel, and is held in that position
while starting the vehicle, damage
may occur to the hydraulic power
steering system and there may be
loss of power steering assist.
Starting Procedure (Key Access)
1. With your foot off the accelerator pedal, turn the ignition key to
START. When the engine starts,
let go of the key.
The idle speed will go down as
the engine warms. Do not race
the engine immediately after
starting it. Allow the oil to warm
up and lubricate all moving
parts.
{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 hold the key in START
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 key, 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.
Starting Procedure (Keyless
Access)
1. With the Keyless Access system, the RKE transmitter
must be in the vehicle. Press the
ENGINE START/STOP button
with the brake pedal applied.
When the engine begins
cranking, let go of the button.
The idle speed will go down as
the engine gets warm. Do not
race the engine immediately
after starting it.
Page 205 of 407

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.
Page 206 of 407

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.
Page 207 of 407

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.
Page 208 of 407

Black plate (23,1)Buick LaCrosse Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707475) - 2015 - CRC - 10/9/14
Driving and Operating 9-23
{Warning
Improper use of the heater cord
or an extension cord can damage
the cord and may result in
overheating and fire.
.Plug the cord into a
three-prong electrical utility
receptacle that is protected
by a ground fault detection
function. An ungrounded
outlet could cause an electric
shock.
.Use a weatherproof,
heavy-duty, 15 amp-rated
extension cord if needed.
Failure to use the
recommended extension cord
in good operating condition,
or using a damaged heater or
extension cord, could make it(Continued)
Warning (Continued)
overheat and cause a fire,
property damage, electric
shock, and injury.
.Do not operate the vehicle
with the heater cord
permanently attached to the
vehicle. Possible heater cord
and thermostat damage could
occur.
.While in use, do not let the
heater cord touch vehicle
parts or sharp edges. Never
close the hood on the
heater cord.
.Before starting the vehicle,
unplug the cord, reattach the
cover to the plug, and
securely fasten the cord.
Keep the cord away from any
moving parts. 4. Before starting the engine, be
sure to unplug and store the
cord as it was before to keep it
away from moving engine parts.
The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Retained Accessory
Power (RAP)
These vehicle accessories can be
used for up to 10 minutes after the
engine is turned off:
.Infotainment System
.Power Windows
.Sunroof (If Equipped)
.Auxiliary Power Outlet
Power to the audio system will
continue to operate for up to
10 minutes or until the driver door is
opened.