brake BUICK LUCERNE 2007 Owner's Guide

Control of a Vehicle
You have three systems that make your
vehicle go where you want it to go. They are the
brakes, the steering, and the accelerator. All
three systems have to do their work at the places
where the tires meet the road.
Sometimes, as when you are driving on snow or
ice, it is easy to ask more of those control systems
than the tires and road can provide. That means
you can lose control of your vehicle. SeeTraction
Control System (TCS) on page 283.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 325.
Braking
SeeBrake System Warning Light on page 201.
Braking action involves perception time and
reaction time.
First, you have to decide to push on the brake
pedal. That is perception time. Then you have to
bring up your foot and do it. That is reaction time.
Average reaction time is about three-fourths of a
second. But that is only an average. It might be less
with one driver and as long as two or three seconds
or more with another. Age, physical condition,
alertness, coordination, and eyesight all play a part.
So do alcohol, drugs, and frustration. But even in
three-fourths of a second, a vehicle moving at
60 mph (100 km/h) travels 66 feet (20 m). That
could be a lot of distance in an emergency, so
keeping enough space between your vehicle and
others is important.
And, of course, actual stopping distances vary
greatly with the surface of the road, whether it is
pavement or gravel; the condition of the road,
whether it is wet, dry, or icy; tire tread; the
condition of the brakes; the weight of the vehicle;
and the amount of brake force applied.
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Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by
heavy braking — rather than keeping pace with
traffic. This is a mistake. The brakes may not have
time to cool between hard stops. The brakes
will wear out much faster if you do a lot of heavy
braking. If you keep pace with the traffic and
allow realistic following distances, you will
eliminate a lot of unnecessary braking. That means
better braking and longer brake life.
If your vehicle’s engine ever stops while you are
driving, brake normally but do not pump the
brakes. If you do, the pedal may get harder to
push down. If the engine stops, you will still have
some power brake assist. But you will use it
when you brake. Once the power assist is used
up, it may take longer to stop and the brake pedal
will be harder to push.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 325.Anti-Lock Brake System (ABS)
Your vehicle has the Anti-Lock Brake System
(ABS), an advanced electronic braking system
that will help prevent a braking skid.
When you start your engine and begin to drive
away, ABS will check itself. You may hear a
momentary motor or clicking noise while this test
is going on, and you may even notice that
your brake pedal moves a little. This is normal.
If there is a problem
with ABS, this warning
light will stay on.
SeeAnti-Lock Brake
System Warning
Light on page 202.
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Let us say the road is wet and you are driving
safely. Suddenly, an animal jumps out in front of
you. You slam on the brakes and continue braking.
Here is what happens with ABS:
A computer senses that wheels are slowing down.
If one of the wheels is about to stop rolling, the
computer will separately work the brakes at each
front wheel and at both rear wheels.ABS can change the brake pressure faster than
any driver could. The computer is programmed
to make the most of available tire and road
conditions. This can help you steer around the
obstacle while braking hard.
As you brake, your computer keeps receiving
updates on wheel speed and controls braking
pressure accordingly.
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Remember: ABS does not change the time you
need to get your foot up to the brake pedal or
always decrease stopping distance. If you get too
close to the vehicle in front of you, you will not have
time to apply your brakes if that vehicle suddenly
slows or stops. Always leave enough room up
ahead to stop, even though you have ABS.
Using ABS
Do not pump the brakes. Just hold the brake pedal
down rmly and let anti-lock work for you. You may
hear the anti-lock pump or motor operate, and feel
the brake pedal pulsate, but this is normal.
Braking in Emergencies
With ABS, you can steer and brake at the same
time. In many emergencies, steering can help you
more than even the very best braking.
Traction Control System (TCS)
Your vehicle has a traction control system that limits
wheel spin. This is especially useful in slippery road
conditions. The system operates only if it senses
that the front wheels are spinning too much or
beginning to lose traction. When this happens, the
system works the front brakes and reduces engine
power (by closing the throttle and managing engine
spark) to limit wheel spin.
The traction control system and StabiliTrak
®
warning light will ash when the traction control
system is limiting wheel spin. SeeTraction Control
System (TCS) Warning Light on page 202for
more information. You may feel or hear the system
working, but this is normal.
If your vehicle is in cruise control when the
traction control system begins to limit wheel spin,
the cruise control will automatically disengage.
When road conditions allow you to safely use
it again, you may re-engage the cruise control.
SeeCruise Control on page 167for more
information.
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The SERVICE TRACTION CONTROL message,
the traction control system warning light and
the StabiliTrak
®warning light will come on to let
you know if there is a problem with the traction
control system. SeeDIC Warnings and Messages
on page 221.
When this light and the SERVICE TRACTION
CONTROL message are on, the system will not
limit wheel spin. Adjust your driving accordingly.
The traction control system automatically
comes on whenever you start your vehicle.
To limit wheel spin, especially in slippery road
conditions, you should always leave the system
on. But you can turn the traction control system off
if you ever need to.
You can turn the system on or off at any time by
pressing the traction control system button located
on the console. The DIC will display TRACTION
CONTROL OFF when you press the button.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 325for more information.
StabiliTrak®System
Your vehicle may have this feature. The
StabiliTrak®system is an advanced computer
controlled system that helps the driver maintain
directional control of the vehicle in difficult driving
conditions. This is accomplished by selectively
applying any one of the vehicle’s brakes and
reducing engine power. The StabiliTrak
®system
comes on automatically whenever you start
your vehicle. The system cannot be turned off.
The STABILITRAK NOT READY message may be
displayed in the DIC and the traction control system
and StabiliTrak
®warning light on the instrument
panel cluster will be on after rst driving the vehicle
and exceeding 19 mph (30 km/h) for 30 seconds.
The StabiliTrak
®system is off until the light has
turned off. This could take up to 15 minutes.
The traction control system and StabiliTrak
®
warning light on the instrument panel cluster will
ash when the system is operating. SeeTraction
Control System (TCS) Warning Light on page 202,
StabiliTrak
®Indicator Light on page 203andDIC
Warnings and Messages on page 221for more
information. You may also feel or hear the system
working. This is normal.
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The SERVICE STABILITRAK message will be
displayed and the traction control system
and StabiliTrak
®warning light on the instrument
panel cluster will come on if there is a problem with
the system. When this light and the SERVICE
STABILITRAK message are on, the system is not
operational. Adjust your driving accordingly.
Panic Brake Assist
Your vehicle may have a panic brake assist system
that monitors the intention of the driver while
braking. If the system senses that the driver has
applied hard/fast pressure to the brake pedal, the
system will generate additional pressure, making it
easier for the driver to maintain brake application.
When this happens the brake pedal will feel easier
to push. Just hold the brake pedal down rmly and
let the system work for you. You may feel the
brakes vibrate, or you may notice some noise but
this is normal. The brakes will return to normal
operation after the brake pedal has been released.
Steering
Power Steering
If you lose power steering assist because the
engine stops or the system is not functioning,
you can steer but it will take much more effort.
Steering Tips
It is important to take curves at a reasonable
speed.
A lot of the “driver lost control” accidents mentioned
on the news happen on curves. Here is why:
Experienced driver or beginner, each of us is
subject to the same laws of physics when driving on
curves. The traction of the tires against the road
surface makes it possible for the vehicle to change
its path when you turn the front wheels. If there is
no traction, inertia will keep the vehicle going in the
same direction. If you have ever tried to steer a
vehicle on wet ice, you will understand this.
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Steering in Emergencies
There are times when steering can be more
effective than braking. For example, you come
over a hill and nd a truck stopped in your lane,
or a car suddenly pulls out from nowhere, or
a child darts out from between parked cars and
stops right in front of you. You can avoid
these problems by braking — if you can stop in
time. But sometimes you cannot; there is not room.
That is the time for evasive action — steering
around the problem.
Your vehicle can perform very well in emergencies
like these. First apply your brakes.
SeeBraking on page 280. It is better to remove as
much speed as you can from a possible collision.
Then steer around the problem, to the left or
right depending on the space available.An emergency like this requires close attention and
a quick decision. If you are holding the steering
wheel at the recommended 9 and 3 o’clock
positions, you can turn it a full 180 degrees very
quickly without removing either hand. But you
have to act fast, steer quickly, and just as quickly
straighten the wheel once you have avoided
the object.
The fact that such emergency situations are always
possible is a good reason to practice defensive
driving at all times and wear safety belts properly.
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Watch for traffic signs, pavement markings, and
lines. If you can see a sign up ahead that might
indicate a turn or an intersection, delay your
pass. A broken center line usually indicates it is
all right to pass, providing the road ahead is
clear. Never cross a solid line on your side of
the lane or a double solid line, even if the road
seems empty of approaching traffic.
Do not get too close to the vehicle you want to
pass while you are awaiting an opportunity. For
one thing, following too closely reduces your
area of vision, especially if you are following a
larger vehicle. Also, you will not have adequate
space if the vehicle ahead suddenly slows or
stops. Keep back a reasonable distance.
When it looks like a chance to pass is coming
up, start to accelerate but stay in the right lane
and do not get too close. Time your move so
you will be increasing speed as the time comes
to move into the other lane. If the way is clear to
pass, you will have a running start that more
than makes up for the distance you would lose
by dropping back. And if something happens to
cause you to cancel your pass, you need only
slow down and drop back again and wait for
another opportunity.
If other vehicles are lined up to pass a slow
vehicle, wait your turn. But take care that
someone is not trying to pass you as you pull
out to pass the slow vehicle. Remember to
glance over your shoulder and check the
blind spot.
Check your vehicle’s mirrors, glance over your
shoulder, and start your left lane change signal
before moving out of the right lane to pass.
When you are far enough ahead of the passed
vehicle to see its front in your vehicle’s inside
mirror, activate the right lane change signal and
move back into the right lane. Remember that
your vehicle’s passenger side outside mirror is
convex. The vehicle you just passed may seem
to be farther away from you than it really is.
Try not to pass more than one vehicle at a time
on two-lane roads. Reconsider before passing
the next vehicle.
Do not overtake a slowly moving vehicle too
rapidly. Even though the brake lamps are not
ashing, it may be slowing down or starting
to turn.
If you are being passed, make it easy for the
following driver to get ahead of you. Perhaps
you can ease a little to the right.
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Loss of Control
Let us review what driving experts say about what
happens when the three control systems — brakes,
steering, and acceleration — do not have enough
friction where the tires meet the road to do what the
driver has asked.
In any emergency, do not give up. Keep trying to
steer and constantly seek an escape route or
area of less danger.
Skidding
In a skid, a driver can lose control of the vehicle.
Defensive drivers avoid most skids by taking
reasonable care suited to existing conditions, and
by not overdriving those conditions. But skids
are always possible.
The three types of skids correspond to your
vehicle’s three control systems. In the braking skid,
your wheels are not rolling. In the steering or
cornering skid, too much speed or steering in a
curve causes tires to slip and lose cornering force.
And in the acceleration skid, too much throttle
causes the driving wheels to spin.A cornering skid is best handled by easing your
foot off the accelerator pedal.
Remember: Any traction control system helps
avoid only the acceleration skid. If your traction
control system is off, then an acceleration
skid is also best handled by easing your foot off
the accelerator pedal.
If your vehicle starts to slide, ease your foot off
the accelerator pedal and quickly steer the
way you want the vehicle to go. If you start
steering quickly enough, your vehicle may
straighten out. Always be ready for a second skid
if it occurs.
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Of course, traction is reduced when water, snow,
ice, gravel, or other material is on the road.
For safety, you will want to slow down and adjust
your driving to these conditions. It is important
to slow down on slippery surfaces because
stopping distance will be longer and vehicle control
more limited.
While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration, or
braking, including reducing vehicle speed by
shifting to a lower gear. Any sudden changes could
cause the tires to slide. You may not realize the
surface is slippery until your vehicle is skidding.
Learn to recognize warning clues — such as
enough water, ice, or packed snow on the road to
make a mirrored surface — and slow down when
you have any doubt.
Remember: Any Anti-Lock Brake System (ABS)
helps avoid only the braking skid.Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to
be impaired — by alcohol or drugs, with night
vision problems, or by fatigue.
Here are some tips on night driving.
Drive defensively.
Do not drink and drive.
Adjust the inside rearview mirror to reduce the
glare from headlamps behind you.
Since you cannot see as well, you may need
to slow down and keep more space between
you and other vehicles.
Slow down, especially on higher speed roads.
Your vehicle’s headlamps can light up only so
much road ahead.
In remote areas, watch for animals.
If you are tired, pull off the road in a safe
place and rest.
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