wheel BUICK LUCERNE 2010 Service Manual

ABS can change the brake pressure to each wheel, as
required, faster than any driver could. This can help the
driver steer around the obstacle while braking hard.
As the brakes are applied, the computer keeps
receiving updates on wheel speed and controls braking
pressure accordingly.
Remember: ABS does not change the time needed to
get a foot up to the brake pedal or always decrease
stopping distance. If you get too close to the vehicle in
front of you, there will not be enough time to apply the
brakes if that vehicle suddenly slows or stops. Always
leave enough room up ahead to stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold the brake pedal
down firmly and let antilock work. The antilock pump or
motor operating might be heard and the brake pedal
might be felt to pulsate, but this is normal.
Braking in Emergencies
ABS allows the driver to steer and brake at the same
time. In many emergencies, steering can help more
than even the very best braking.
Brake Assist
This vehicle has a Brake Assist feature designed to
assist the driver in stopping or decreasing vehicle
speed in emergency driving conditions. This feature
uses the stability system hydraulic brake control module
to supplement the power brake system under conditions
where the driver has quickly and forcefully applied the
brake pedal in an attempt to quickly stop or slow down
the vehicle. The stability system hydraulic brake control
module increases brake pressure at each corner of the
vehicle until the ABS activates. Minor brake pedal
pulsations or pedal movement during this time is normal
and the driver should continue to apply the brake pedal
as the driving situation dictates The Brake Assist
feature will automatically disengage when the brake
pedal is released or brake pedal pressure is quickly
decreased.
5-5

StabiliTrak®System
The vehicle may have the StabiliTrak system which
combines antilock brake, traction and stability control
systems and helps the driver maintain directional
control of the vehicle in most 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 the vehicle is started. The system cannot be
turned off.
This light will flash when
the system is operating.
The STABILITRAK NOT READY message may be
displayed in the Driver Information Center (DIC) and the
Traction Control System (TCS)/StabiliTrak warning light
on the instrument panel cluster comes on after first
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 TCS/StabiliTrak warning light on the instrument
panel cluster will flash when the system is operating.
See
Traction Control System (TCS) Warning Light
on
page 4‑38and StabiliTrak®Indicator Lighton
page 4‑39for more information. The system may be
heard or felt while it is working. This is normal.
The SERVICE STABILITRAK message is displayed and
the TCS/StabiliTrak warning light on the instrument
panel cluster comes on if there is a problem with
the system. When this light and the SERVICE
STABILITRAK message are on, the system is not
working. Adjust your driving accordingly.
Traction Control System (TCS)
The vehicle has a Traction Control System (TCS) 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.
5-6

The TCS and StabiliTrak®
light will flash when the
system is limiting
wheel spin.
The system may be heard or felt while it is working, but
this is normal. See Traction Control System (TCS)
Warning Light
on page 4‑38for more information.
If the vehicle is in cruise control when TCS begins to
limit wheel spin, the cruise control will automatically
disengage. The cruise control may be re-engaged when
road conditions allow. See Cruise Control on page 4‑9.
The SERVICE TRACTION CONTROL message in the
DIC and the TCS/StabiliTrak warning light comes on if
there is a problem with the traction control system. See
DIC Warnings and Messages on page 4‑55.
When this light and the SERVICE TRACTION
CONTROL message are on, the system will not limit
wheel spin. Adjust your driving accordingly.
To turn the system off or
on, press and release this
button located in front of
the shift lever.
TCS automatically comes on whenever the vehicle is
started. To limit wheel spin, especially in slippery road
conditions, always leave the system turned on. TCS
can be turned off if needed.
The system can be turned on or off at any time by
pressing the TCS button. The DIC will display
TRACTION CONTROL OFF when the button is
pressed, and part of the traction control system is
disabled. The vehicle will still have brake-traction
control, but will not be able to use the engine speed
management system. System noises may be heard as
a result of the brake-traction control working. If the
controller detects excessive wheel spin in this mode,
the TCS/StabiliTrak light may blink.
5-7

It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn the
system off if the vehicle is stuck in sand, mud, ice or
snow, and you want to“rock”the vehicle to attempt to
free it. See If Your Vehicle is Stuck in Sand, Mud, Ice,
or Snow on page 5‑18.
Adding non‐dealer/non‐retailer accessories can affect
the vehicle's performance. See Accessories and
Modifications
on page 6‑3for more information.
Magnetic Ride Control™
The vehicle may have Magnetic Ride Control that
automatically adjusts the ride of the vehicle. The
controller receives input from the system to determine
the proper ride. If the controller detects a problem within
the system, the Driver Information Center (DIC) displays
a SERVICE SUSPENSION SYS message. See DIC
Warnings and Messages
on page 4‑55for more
information. If this message appears, have the vehicle
serviced at your dealer.
Steering
Power Steering
If power steering assist is lost because the engine stops
or the system is not functioning, the vehicle can be
steered but it will take more effort.
Steering Tips
It is important to take curves at a reasonable speed.
Traction in a curve depends on the condition of the tires
and the road surface, the angle at which the curve is
banked, and vehicle speed. While in a curve, speed is
the one factor that can be controlled.
If there is a need to reduce speed, do it before entering
the curve, while the front wheels are straight.
Try to adjust the speed so you can drive through the
curve. Maintain a reasonable, steady speed. Wait to
accelerate until out of the curve, and then accelerate
gently into the straightaway.
5-8

Steering in Emergencies
There are times when steering can be more effective
than braking. For example, you come over a hill and
find 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. These
problems can be avoided by braking—if you can
stop in time. But sometimes you cannot stop in time
because there is no room. That is the time for evasive
action —steering around the problem.
The vehicle can perform very well in emergencies
like these. First apply the brakes. See Braking
on
page 5‑3. It is better to remove as much speed as
possible from a 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 holding the steering wheel at the
recommended 9 and 3 o'clock positions, it can be
turned 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.
5-9

Off-Road Recovery
The vehicle's right wheels can drop off the edge of a
road onto the shoulder while driving.
If the level of the shoulder is only slightly below the
pavement, recovery should be fairly easy. Ease off the
accelerator and then, if there is nothing in the way, steer
so that the vehicle straddles the edge of the pavement.
Turn the steering wheel 8 to 13 cm (3 to 5 inches),
about one-eighth turn, until the right front tire contacts
the pavement edge. Then turn the steering wheel to go
straight down the roadway.
Passing
Passing another vehicle on a two-lane road can be
dangerous. To reduce the risk of danger while passing:
.Look down the road, to the sides, and to
crossroads for situations that might affect a
successful pass. If in doubt, wait.
.Watch for traffic signs, pavement markings, and
lines that could indicate a turn or an intersection.
Never cross a solid or double‐solid line on your
side of the lane.
.Do not get too close to the vehicle you want to
pass. Doing so can reduce your visibility.
.Wait your turn to pass a slow vehicle.
.When you are being passed, ease to the right.
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.
5-10

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 the vehicle's
three control systems. In the braking skid, the 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.
Remember: Any traction control system helps avoid
only the acceleration skid. If the traction control system
is off, then an acceleration skid is best handled by
easing your foot off the accelerator pedal.
If the 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,
the vehicle may straighten out. Always be ready for a
second skid if it occurs.Of course, traction is reduced when water, snow, ice,
gravel, or other material is on the road. For safety, 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 the 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: Antilock brakes help avoid only the
braking skid.
5-11

{WARNING:
Coasting downhill in N (Neutral) or with the
ignition off is dangerous. The brakes will have to
do all the work of slowing down and they could
get so hot that they would not work well. You
would then have poor braking or even none going
down a hill. You could crash. Always have the
engine running and the vehicle in gear when
going downhill.
.Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds that
let you stay in your own lane.
.Top of hills: Be alert—something could be in your
lane (stalled car, accident).
.Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow or ice between the
tires and the road, creating less traction or grip. Wet ice
can occur at about 0°C (32°F) when freezing rain
begins to fall, resulting in even less traction. Avoid
driving on wet ice or in freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the condition. Accelerate
gently so traction is not lost. Accelerating too quickly
causes the wheels to spin and makes the surface under
the tires slick, so there is even less traction.
Try not to break the fragile traction. If you accelerate too
fast, the drive wheels will spin and polish the surface
under the tires even more.
5-15

If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
Slowly and cautiously spin the wheels to free the
vehicle when stuck in sand, mud, ice, or snow. See
Rocking Your Vehicle to Get It Out on page 5‑18.
If the vehicle has a traction system, it can often help to
free a stuck vehicle. Refer to the vehicle's traction
system in the Index. If stuck too severely for the traction
system to free the vehicle, turn the traction system off
and use the rocking method.
{WARNING:
If the vehicle's tires spin at high speed, they
can explode, and you or others could be injured.
The vehicle can overheat, causing an engine
compartment fire or other damage. Spin the
wheels as little as possible and avoid going above
55 km/h (35 mph) as shown on the speedometer.
For information about using tire chains on the vehicle,
see Tire Chains on page 6‑80.
Rocking Your Vehicle to Get It Out
Turn the steering wheel left and right to clear the area
around the front wheels. Turn off any traction or stability
system. Shift back and forth between R (Reverse) and a
forward gear, spinning the wheels as little as possible.
To prevent transmission wear, wait until the wheels stop
spinning before shifting gears. Release the accelerator
pedal while shifting, and press lightly on the accelerator
pedal when the transmission is in gear. Slowly spinning
the wheels in the forward and reverse directions causes
a rocking motion that could free the vehicle. If that does
not get the vehicle out after a few tries, it might need to
be towed out. If the vehicle does need to be towed out,
seeTowing Your Vehicle on page 5‑24.
5-18

If things like suitcases, tools, packages,
or anything else are put inside the vehicle, they
will go as fast as the vehicle goes. If you have to
stop or turn quickly, or if there is a crash, they will
keep going.
{WARNING:
Things you put inside the vehicle can strike
and injure people in a sudden stop or turn,
or in a crash.
.Put things in the cargo area of the
vehicle. In the cargo area, put them as
far forward as you can. Try to spread the
weight evenly.
.Never stack heavier things, like
suitcases, inside the vehicle so that
some of them are above the tops of the
seats.
(Continued)
WARNING: (Continued)
.Do not leave an unsecured child restraint
in the vehicle.
.When you carry something inside the
vehicle, secure it whenever you can.
.Do not leave a seat folded down unless
you need to.
Towing
Towing Your Vehicle
To avoid damage, the disabled vehicle should be towed
with all four wheels off the ground. Consult your dealer
or a professional towing service if the disabled vehicle
must be towed. SeeRoadside Assistance Program
on
page 8‑8.
To tow the vehicle behind another vehicle for
recreational purposes, such as behind a motorhome,
see “Recreational Vehicle Towing” following.
5-24