2011 BUICK LACROSSE service

Black plate (41,1)Buick LaCrosse Owner Manual - 2011
Seats and Restraints 3-41
Additional Factors Affecting
System Operation
Safety belts help keep the
passenger in position on the
seat during vehicle maneuvers
and braking, which helps the
passenger sensing system
maintain the passenger airbag
status. See“Safety Belts” and
“Child Restraints” in the Index for
additional information about the
importance of proper restraint use.
A thick layer of additional material,
such as a blanket or cushion,
or aftermarket equipment such
as seat covers, seat heaters, and
seat massagers can affect how
well the passenger sensing system
operates. We recommend that
you not use seat covers or other
aftermarket equipment except when
approved by GM for your specific
vehicle. See Adding Equipment to
the Airbag-Equipped Vehicle on
page 3‑42 for more information
about modifications that can
affect how the system operates.
{WARNING
Stowing of articles under the
passenger seat or between the
passenger seat cushion and
seatback may interfere with the
proper operation of the passenger
sensing system.
Servicing the
Airbag-Equipped Vehicle
Airbags affect how the vehicle
should be serviced. There are
parts of the airbag system in
several places around the vehicle.
Your dealer and the service manual
have information about servicing
the vehicle and the airbag system.
To purchase a service manual,
see Service Publications Ordering
Information on page 13‑15.
{WARNING
For up to 10 seconds after the
ignition is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
proper service procedures, and
make sure the person performing
work for you is qualified to do so.

Black plate (43,1)Buick LaCrosse Owner Manual - 2011
Seats and Restraints 3-43
In addition, your dealer and the
service manual have information
about the location of the airbag
sensors, sensing and diagnostic
module and airbag wiring.
Airbag System Check
The airbag system does not need
regularly scheduled maintenance
or replacement. Make sure the
airbag readiness light is working.
SeeAirbag Readiness Light on
page 5‑14 for more information.
Notice: If an airbag covering is
damaged, opened, or broken,
the airbag may not work properly.
Do not open or break the airbag
coverings. If there are any
opened or broken airbag covers,
have the airbag covering and/or
airbag module replaced. For the
location of the airbag modules,
see What Makes an Airbag
Inflate? on page 3‑34. See your
dealer for service.
Replacing Airbag System
Parts After a Crash
{WARNING
A crash can damage the
airbag systems in the vehicle.
A damaged airbag system
may not work properly and
may not protect you and your
passenger(s) in a crash, resulting
in serious injury or even death.
To help make sure the airbag
systems are working properly
after a crash, have them
inspected and any necessary
replacements made as soon
as possible. If an airbag inflates, you will need
to replace airbag system parts.
See your dealer for service.
If the airbag readiness light stays on
after the vehicle is started or comes
on when you are driving, the airbag
system may not work properly.
Have the vehicle serviced right
away. See
Airbag Readiness Light
on page 5‑14 for more information.

Black plate (12,1)Buick LaCrosse Owner Manual - 2011
5-12 Instruments and Controls
Metric
When the ignition is on, the fuel
gauge indicates about how much
fuel is left in the tank. An arrow on the fuel gauge
indicates the side of the vehicle
the fuel door is on.
When the indicator nears empty,
the low fuel light comes on. There is
still a little fuel left, but the fuel tank
should be filled soon.
Here are four things that some
owners ask about. None of these
show a problem with the fuel gauge:
.At the service station, the fuel
pump shuts off before the gauge
reads full.
.It takes a little more or less
fuel to fill up than the gauge
indicated. For example, the
gauge indicated the tank was
half full, but it actually took a
little more or less than half the
tank's capacity to fill the tank.
.The gauge moves a little while
turning a corner or speeding up.
.The gauge takes a few seconds
to stabilize after the ignition is
turned on, and goes back to
empty when the ignition is
turned off.

Black plate (15,1)Buick LaCrosse Owner Manual - 2011
Instruments and Controls 5-15
The airbag readiness light comes
on solid and stays on for several
seconds when the vehicle is started.
Then the light goes out.
If it stays on solid after the vehicle
has been started or comes on while
driving, the airbag system may not
work properly. Have the vehicle
serviced right away.
{WARNING
If the airbag readiness light stays
on after the vehicle is started or
comes on while driving, it means
the airbag system might not be
working properly. The airbags in
the vehicle might not inflate in a
crash, or they could even inflate
without a crash. To help avoid
injury, have the vehicle serviced
right away.
Passenger Airbag Status
Indicator
The vehicle has a passenger
sensing system. SeePassenger
Sensing System on page 3‑37
for important safety information.
The instrument panel has a
passenger airbag status indicator.
When the vehicle is started, the
passenger airbag status indicator
will light the words ON and OFF for
several seconds as a system check.

Black plate (16,1)Buick LaCrosse Owner Manual - 2011
5-16 Instruments and Controls
If you are using remote start,
if equipped, to start the vehicle
from a distance, you may not see
the system check. Then, after
several more seconds, the status
indicator will light either the word
ON or OFF to let you know the
status of the right front passenger
frontal airbag.
If the word ON is lit on the
passenger airbag status indicator,
it means that the right front
passenger frontal airbag is
enabled (may inflate).
If the word OFF is lit on the airbag
status indicator, it means that the
passenger sensing system has
turned off the right front passenger
frontal airbag.If, after several seconds, both
status indicator lights remain on,
or if there are no lights at all, there
may be a problem with the lights
or the passenger sensing system.
See your dealer for service.
{WARNING
If the airbag readiness light
ever comes on and stays on,
it means that something may be
wrong with the airbag system.
To help avoid injury to yourself or
others, have the vehicle serviced
right away. See
Airbag Readiness
Light on page 5‑14 for more
information, including important
safety information.
Charging System Light
The charging system light comes
on briefly when the ignition is turned
on, but the engine is not running, as
a check to show the light is working.
The light turns off when the engine
is started. If it does not, have the
vehicle serviced by your dealer.
If the light stays on, or comes on
while driving, there could be a
problem with the electrical charging
system. Have it checked by your
dealer. Driving while this light is
on could drain the battery.
If a short distance must be driven
with the light on, be sure to turn off
all accessories, such as the radio
and air conditioner.

Black plate (17,1)Buick LaCrosse Owner Manual - 2011
Instruments and Controls 5-17
Malfunction
Indicator Lamp
A computer system called OBD II
(On-Board Diagnostics-Second
Generation) monitors operation
of the fuel, ignition, and emission
control systems. It ensures that
emissions are at acceptable levels
for the life of the vehicle, helping
to produce a cleaner environment.
This light should come on when the
ignition is on, but the engine is not
running, as a check to show it is
working. If it does not, have the
vehicle serviced by your dealer.If the malfunction indicator lamp
comes on and stays on while the
engine is running, this indicates
that there is an OBD II problem
and service is required.
Malfunctions often are indicated by
the system before any problem is
apparent. Being aware of the light
can prevent more serious damage
to the vehicle. This system assists
the service technician in correctly
diagnosing any malfunction.
Notice:
If the vehicle is
continually driven with this
light on, after a while, the
emission controls might not
work as well, the vehicle fuel
economy might not be as good,
and the engine might not run
as smoothly. This could lead to
costly repairs that might not be
covered by the vehicle warranty. Notice:
Modifications made
to the engine, transmission,
exhaust, intake, or fuel system
of the vehicle or the replacement
of the original tires with other
than those of the same Tire
Performance Criteria (TPC)
can affect the vehicle's
emission controls and can
cause this light to come on.
Modifications to these systems
could lead to costly repairs not
covered by the vehicle warranty.
This could also result in a failure
to pass a required Emission
Inspection/Maintenance test.
See Accessories and
Modifications on page 10‑3.
This light comes on during a
malfunction in one of two ways:
Light Flashing: A misfire condition
has been detected. A misfire
increases vehicle emissions and
could damage the emission control
system on the vehicle. Diagnosis
and service might be required.

Black plate (18,1)Buick LaCrosse Owner Manual - 2011
5-18 Instruments and Controls
To prevent more serious damage to
the vehicle:
.Reduce vehicle speed.
.Avoid hard accelerations.
.Avoid steep uphill grades.
.If towing a trailer, reduce the
amount of cargo being hauled
as soon as it is possible.
If the light continues to flash,
when it is safe to do so, stop the
vehicle. Find a safe place to park
the vehicle. Turn the vehicle off,
wait at least 10 seconds, and
restart the engine. If the light is
still flashing, follow the previous
steps and see your dealer for
service as soon as possible.
Light On Steady: An emission
control system malfunction has
been detected on the vehicle.
Diagnosis and service might
be required. The following may correct an
emissions system malfunction:
.Make sure the fuel cap is
fully installed. See
Filling
the Tank on page 9‑53.
The diagnostic system can
determine if the fuel cap has
been left off or improperly
installed. A loose or missing
fuel cap allows fuel to evaporate
into the atmosphere. A few
driving trips with the cap
properly installed should
turn the light off.
.Make sure the electrical
system is not wet. The system
could be wet if the vehicle was
driven through a deep puddle of
water. The condition is usually
corrected when the electrical
system dries out. A few driving
trips should turn the light off.
.Make sure to fuel the vehicle
with quality fuel. Poor fuel quality
causes the engine not to run as
efficiently as designed and can
cause: stalling after start-up,
stalling when the vehicle is
changed into gear, misfiring,
hesitation on acceleration,
or stumbling on acceleration.
These conditions might go away
once the engine is warmed up.
If one or more of these
conditions occurs, change the
fuel brand used. It will require at
least one full tank of the proper
fuel to turn the light off.
See Recommended Fuel on
page 9‑50.
If none of the above have made
the light turn off, your dealer can
check the vehicle. The dealer
has the proper test equipment
and diagnostic tools to fix any
mechanical or electrical problems
that might have developed.

Black plate (19,1)Buick LaCrosse Owner Manual - 2011
Instruments and Controls 5-19
Emissions Inspection and
Maintenance Programs
Some state/provincial and
local governments may have
programs to inspect the on-vehicle
emission control equipment.
For the inspection, the emission
system test equipment is connected
to the vehicle’s Data Link
Connector (DLC).
The DLC is under the instrument
panel to the left of the steering
wheel. See your dealer if assistance
is needed.The vehicle may not pass
inspection if:
.The malfunction indicator lamp is
on with the engine running, or if
the light does not come on when
the ignition is turned to ON/RUN
while the engine is off.
.The critical emission control
systems have not been
completely diagnosed by
the system. This can happen
if the battery has recently
been replaced or if the battery
has run down. The diagnostic
system evaluates critical
emission control systems during
normal driving. This can take
several days of routine driving.
If this has been done and the
vehicle still does not pass the
inspection, your dealer can
prepare the vehicle for
inspection.
Brake System Warning
Light
The vehicle brake system
consists of two hydraulic circuits.
If one circuit is not working, the
remaining circuit can still work to
stop the vehicle. For normal braking
performance, both circuits need to
be working.
If the warning light comes on, there
is a brake problem. Have your brake
system inspected right away.
EnglishMetric
If the vehicle has antilock brakes,
this light should come on when the
vehicle is placed in START. If it does
not, have the vehicle serviced by
your dealer.