ignition BUICK LACROSSE 2005 Service Manual

Brake System Warning Light
Your vehicle’s hydraulic brake system is divided into
two parts. If one part is not working, the other part can
still work and stop you. For good braking, though,
you need both parts working well.
If the warning light comes on and the parking brake is
not applied, there is a brake problem. Have your
brake system inspected right away.
This light should come on
briey when you turn the
ignition key to RUN.
If it does not come on then, have it xed so it will be
ready to warn you if there is a problem.When the ignition is on, the brake system warning light
will also come on when you set your parking brake.
The light will stay on if your parking brake does
not release fully. If it stays on after your parking brake is
fully released, it means you have a brake problem.
If the light comes on while you are driving, a chime will
sound and you should pull off the road and stop
carefully. You may notice that the pedal is harder to
push. Or, the pedal may go closer to the oor. It
may take longer to stop. If the light is still on, have the
vehicle towed for service. SeeTowing Your Vehicle
on page 4-34.
{CAUTION:
Your brake system may not be working
properly if the brake system warning light is on.
Driving with the brake system warning light on
can lead to an accident. If the light is still on
after you have pulled off the road and stopped
carefully, have the vehicle towed for service.
3-36

Anti-Lock Brake System
Warning Light
With the anti-lock brake
system, the light will come
on when your engine is
started and may stay on
for several seconds. That
is normal.
If the ABS warning light comes on and stays on, there
may be a problem with the anti-lock portion of the brake
system. If the brake system warning light is not on,
you still have brakes, but you do not have anti-lock
brakes. SeeBrake System Warning Light on page 3-36.
If the light stays on, turn the ignition to OFF. If the
light comes on when you are driving, stop as soon as
possible and turn the ignition off. Then start the
engine again to reset the system. If the light still stays
on, or comes on again while you are driving, your
vehicle needs service. If the regular brake system
warning light is not on, you still have brakes, but you do
not have anti-lock brakes. If the regular brake system
warning light is also on, you do not have anti-lock brakes
and there is a problem with your regular brakes. See
Brake System Warning Light on page 3-36.
Traction Control System (TCS)
Warning Light
If the TC (traction control)
warning light comes on
and stays on, there may be
a problem with the
traction control system
and, if equipped, the
StabiliTrak
®system.
The TC (traction control) warning light will come on
briey when you turn the ignition to RUN. If it does not
come on then, have it xed so it will be ready to
warn you if there is a problem.
The light will also come on if you turn the traction
control system off using the TC (traction control) on/off
button located near the shift lever.
If the TC (traction control) warning light stays on or
comes on while you are driving, pull off the road as soon
as possible and stop carefully. Try resetting the
system by turning the ignition off then back on. If the
light still stays on or comes back on again while you are
driving, your vehicle needs service. Have the traction
control system and, if equipped, the StabiliTrak
®system
inspected as soon as possible. SeeTraction Control
System (TCS) on page 4-8andStabiliTrak
®System on
page 4-9for more information.
3-37

Low Coolant Warning Light
If equipped, this light
comes on briey when you
turn your ignition on as
a bulb check only.
Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition, and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for thelife of the vehicle, helping to produce a cleaner
environment. The check engine light comes on to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
Notice:If you keep driving your vehicle with this
light on, after awhile, your emission controls
may not work as well, your fuel economy may not
be as good, and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.
Notice:Modications made to the engine,
transaxle, exhaust, intake, or fuel system of your
vehicle or the replacement of the original tires with
other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test.
3-39

This light should come on, as a check to show you it is
working, when the ignition is on and the engine is
not running. If the light does not come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
If the Light is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possibleIf the light stops ashing and remains on steady, see “If
the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see “If
the Light Is On Steady” following. If the light is still
ashing, follow the previous steps, and see your dealer
for service as soon as possible.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. SeeFilling the Tank on page 5-8. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. A loose or missing
fuel cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
3-40

Oil Pressure Light
If the vehicle has an oil
problem, this light may
stay on after the engine is
started, or come on
while you are driving.
This light indicates that oil is not going through the
engine quickly enough to keep it lubricated. The engine
could be low on oil or could have some other oil
problem. Have it xed right away.
The oil light could also come on in the following
situations:
The light will come on briey when the ignition is
turned on to show that it is working properly. If it
does not come on with the ignition on, there may be
a problem with the fuse or bulb. Have it xed
right away.
Sometimes when the engine is idling at a stop, a
chime will sound and the light may blink on and
off. This is normal.
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
3-42

Low Washer Fluid Warning Light
This light will come on
briey when the ignition is
on. If the light stays on,
a chime will sound
indicating your windshield
washer uid is low.
SeeWindshield Washer Fluid on page 5-34for more
information.
Door Ajar Light
When the ignition is on,
this light will stay on until
all doors are closed
and completely latched.
You will hear a chime if a door is unlatched after the
engine is started and the vehicle is not in PARK (P).
Trunk Ajar Light
This light will come on and
a chime will sound if the
trunk is ajar and the
vehicle is not in Park (P).
Try closing the trunk
again. Never drive with the
trunk open.
Service Vehicle Soon Light
If equipped, this light will
come on and a chime will
sound if it detects a
problem on the vehicle.
3-45

Fuel Gage
The fuel gage indicates
about how much fuel is left
in the fuel tank when the
ignition is on.
When the indicator nears empty, there is still a little fuel
left, but you should get more fuel soon.
Here are four things that some owners ask about. All
these things are normal and do not indicate that
anything is wrong with the fuel gage:
At the gas station, the pump shuts off before the
gage reads full.
It takes more, or less, fuel to ll up than the gage
reads. For example, the gage reads half full, but
it took more, or less, than half of the tank’s capacity
to ll it.
The gage pointer may move while cornering,
braking or accelerating.
The gage may not indicate empty when the ignition
is turned off.
Low Fuel Warning Light
If the vehicle’s fuel is low, a light on the fuel gage, if
equipped, will come on and a chime will sound
periodically until fuel is added to the fuel tank.
It will also come on for a few seconds when the ignition
is turned on as a check to indicate it is working. If it
does not come on then, have it xed.
For vehicles with a DIC, a LOW FUEL message will
appear. SeeDIC Warnings and Messages on page 3-53
for more information.
Check Gas Cap Light
If equipped, this light will
come on and a chime will
sound if your gas cap
is not securely fastened.
SeeMalfunction Indicator Lamp on page 3-39for more
information.
3-46

Driver Information Center (DIC)
Your vehicle may have a Driver Information
Center (DIC).
All messages will appear in the DIC display located in
the instrument panel cluster, below the speedometer.
The DIC buttons are located on the center of the
instrument panel, below the center outlets.
The DIC comes on when the ignition is on. After a short
delay, the DIC on the uplevel vehicle will display the
WELCOME DRIVER (1 or 2) if a personalized key 1 or 2
is used, and then the information that was last
displayed before the engine was turned off.
The DIC on the base level vehicle displays the odometer
and trip odometers only.
The DIC on the uplevel vehicle displays the odometer,
trip odometers, fuel economy, trip computer, vehicle
system, and compass display information. It also
displays warning messages if a system problem is
detected. In addition, the DIC on the uplevel vehicle
displays phone numbers that are called using the
OnStar
®system, if equipped. SeeOnStar®System on
page 2-34.The outside air temperature automatically appears in
the bottom right corner of the uplevel DIC display when
viewing the trip/odometer screens, fuel screens and
some of the gages screens. If the outside air
temperature is at or below 37°F (3°C), the temperature
reading will toggle between displaying the outside
temperature and the word ICE for two minutes. If there
is a problem with the system that controls the
temperature display, the letters OC (open circuit) or SC
(short circuit) will appear on the display. If this occurs,
have the vehicle serviced by your GM dealer.
The DIC on the uplevel vehicle also allows some
features to be customized or personalized. SeeDIC
Vehicle Personalization on page 3-71for more
information.
DIC Operation and Displays
The DIC has different modes which can be accessed by
pressing the DIC buttons located on the center of the
instrument panel. Depending on whether your vehicle
has the base level or uplevel DIC, the buttons and
modes available will differ.
The buttons on the base level vehicle are the
trip/odometer and English/Metric buttons.
The buttons on the uplevel vehicle are the trip/odometer,
set/reset, gages, fuel, and option buttons.
The button functions are detailed in the following pages.
3-47

A/C OFF FOR ENGINE PROTECTION
This message will display when the engine coolant
becomes hotter than the normal operating temperature.
SeeEngine Coolant Temperature Gage on page 3-38.
To avoid added strain on a hot engine, the air
conditioning compressor is automatically turned off.
When the coolant temperature returns to normal, the air
conditioning compressor will turn back on. You can
continue to drive your vehicle.
This message will come on while the ignition is in RUN.
Press any of the DIC buttons to acknowledge this
warning message and to clear it from the screen.
This message will continue to display for two seconds if
it has not been acknowledged when the engine is
turned off. It will also re-display for two seconds if the
message has been acknowledged, but the condition still
exists when the engine is turned off.
If the condition still exists, the message will re-appear
when the engine is turned on. If this message continues
to appear, have the system repaired by your GM dealer
as soon as possible to avoid damage to your engine.
BATTERY SAVER ACTIVE
This message will display when the system detects that
the battery voltage is dropping beyond a reasonable
level. The battery saver system will start reducing certain
features of the vehicle that you may be able to notice.At the point that the features are disabled, this message
is displayed. It means that the vehicle is trying to
save the charge in the battery.
Turn off all unnecessary accessories to allow the battery
to recharge.
The normal battery voltage range is 11.5 to 15.5 volts. If
you have an uplevel DIC, you can monitor the battery
voltage by pressing the gages button until BATTERY
displays.
CHANGE OIL SOON
This message will display when service is required for
the vehicle. See your GM dealer. SeeEngine Oil
on page 5-15andScheduled Maintenance on page 6-4
for more information.
The CHANGE OIL SOON message is reset by
acknowledging the message. The OIL LIFE screen
under the gages menu on the DIC must also be reset.
See “Oil Life” underDIC Operation and Displays on
page 3-47andEngine Oil Life System on page 5-18.
This message will display while the ignition is in
RUN. Press any of the DIC buttons to acknowledge this
message and to clear it from the screen.
3-54

This message will continue to display for two seconds if
it has not been acknowledged when the engine is
turned off. It will also re-display for two seconds if the
message has been acknowledged, but the condition still
exists when the engine is turned off.
If the condition still exists, the message will re-appear
when the engine is turned on.
CHARGING SYSTEM FAILURE
This message will display when there is a problem with
the generator and battery charging systems. Driving
with this problem could drain your battery. Turn off all
unnecessary accessories. Stop and turn off the
vehicle as soon as it is safe to do so. Have the electrical
system checked by your GM dealer immediately.
This message will display and a chime will sound while
the ignition is in RUN. Press any of the DIC buttons
to acknowledge this message and to clear it from
the screen.
This message will continue to display for two seconds if
it has not been acknowledged when the engine is
turned off. It will also re-display for two seconds if the
message has been acknowledged, but the condition still
exists when the engine is turned off.
If the condition still exists, the message will re-appear
when the engine is turned on.
CHECK GAS CAP
This message may be displayed if the gas cap is not
on, or is not fully tightened. Check the gas cap to ensure
that it is on properly. The diagnostic system can
determine if the fuel cap has been left off or improperly
installed. A loose or missing fuel cap will allow fuel
to evaporate into the atmosphere. A few driving trips
with the cap properly installed should turn this message
off. SeeFilling the Tank on page 5-8for more
information.
This message will display while the ignition is in RUN.
Press any of the DIC buttons to acknowledge this
message and to clear it from the screen.
This message will continue to display for two seconds if
it has not been acknowledged when the engine is
turned off. It will also re-display for two seconds if the
message has been acknowledged, but the condition still
exists when the engine is turned off.
If the condition still exists, the message will re-appear
when the engine is turned on.
3-55