steering CADILLAC DTS PROFESSIONAL 2007 1.G Service Manual

Control of a Vehicle
The following three systems help to control your
vehicle while driving — brakes, steering, and
accelerator. At times, as when driving on snow or
ice, it is easy to ask more of those control
systems than the tires and road can provide.
Meaning, you can lose control of your vehicle. See
Traction Control System (TCS) on page 309.
Adding non-dealer/non-retailer accessories can
affect your vehicle’s performance. SeeAccessories
and Modications on page 353.
Braking
SeeBrake System Warning Light on page 229.
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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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 the 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 might 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 232and
StabiliTrak
®Indicator Light on page 232for 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 176orAdaptive
Cruise Control on page 179for more information.
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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.
Magnetic Speed Variable Assist
Steering System
This system continuously adjusts the effort you
feel when steering at all vehicle speeds. It provides
ease when parking, yet a rm, solid feel at
highway speeds.
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.
The traction you can get in a curve depends on
the condition of the tires and the road surface, the
angle at which the curve is banked, and your
speed. While you are in a curve, speed is the
one factor you can control.
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Suppose you are steering through a sharp curve.
Then you suddenly accelerate. Both control
systems — steering and acceleration — have to
do their work where the tires meet the road.
Adding the sudden acceleration can demand too
much of those places. You can lose control.
SeeTraction Control System (TCS) on page 309.
What should you do if this ever happens? Ease
up on the accelerator pedal, steer the vehicle the
way you want it to go, and slow down.
If you have StabiliTrak
®, the system may be
active. SeeStabiliTrak®System on page 311.
Speed limit signs near curves warn that you should
adjust your speed. Of course, the posted speeds
are based on good weather and road conditions.
Under less favorable conditions you will want to
go slower.If you need to reduce your speed as you approach
a curve, do it before you enter the curve, while
the front wheels are straight ahead.
Try to adjust your speed so you can “drive”
through the curve. Maintain a reasonable, steady
speed. Wait to accelerate until you are out of
the curve, and then accelerate gently into
the straightaway.
Adding non-dealer/non-retailer accessories can
affect your vehicle’s performance. SeeAccessories
and Modications on page 353.
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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 the brakes. SeeBraking
on page 306. 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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Off-Road Recovery
You may nd that your vehicle’s right wheels have
dropped off the edge of a road onto the shoulder
while you are 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 your vehicle
straddles the edge of the pavement.You can turn the steering wheel up to one-quarter
turn until the right front tire contacts the pavement
edge. Then turn the steering wheel to go
straight down the roadway.
Passing
The driver of a vehicle about to pass another on a
two-lane highway waits for just the right moment,
accelerates, moves around the vehicle ahead, then
goes back into the right lane again. A simple
maneuver?
Not necessarily! Passing another vehicle on a
two-lane highway is a potentially dangerous move,
since the passing vehicle occupies the same lane
as oncoming traffic for several seconds. A
miscalculation, an error in judgment, or a brief
surrender to frustration or anger can suddenly put
the passing driver face to face with the worst of all
traffic accidents — the head-on collision.
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Remember that an outside convex mirror
makes the vehicle you just passed seem 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 might 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.
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,
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.
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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If you have StabiliTrak®, the system may be
active. SeeStabiliTrak®System on page 311.
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, 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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The Anti-Lock Brake System (ABS) improves your
vehicle’s stability when you make a hard stop
on a slippery road. Even though you have ABS,
you will want to begin stopping sooner than
you would on dry pavement. SeeAnti-Lock Brake
System (ABS) on page 307.
Allow greater following distance on any
slippery road.
Watch for slippery spots. The road might be
ne until you hit a spot that is covered with
ice. On an otherwise clear road, ice patches
may appear in shaded areas where the
sun cannot reach, such as around clumps of
trees, behind buildings, or under bridges.
Sometimes the surface of a curve or an
overpass may remain icy when the
surrounding roads are clear. If you see a
patch of ice ahead of you, brake before you
are on it. Try not to brake while you are
actually on the ice, and avoid sudden
steering maneuvers.
If You Are Caught in a Blizzard
If you are stopped by heavy snow, you could be in
a serious situation. You should probably stay
with your vehicle unless you know for sure that you
are near help and you can hike through the
snow. Here are some things to do to summon
help and keep yourself and your passengers safe:
Turn on your hazard ashers.
Tie a red cloth to your vehicle to alert police
that you have been stopped by the snow.
Put on extra clothing or wrap a blanket
around you. If you do not have blankets
or extra clothing, make body insulators from
newspapers, burlap bags, rags, oor
mats — anything you can wrap around
yourself or tuck under your clothing to
keep warm.
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Rocking Your Vehicle to Get It Out
First, turn the steering wheel left and right.
That will clear the area around the front wheels.
You should turn the traction control system
off. SeeTraction Control System (TCS) on
page 309. Then shift back and forth between
REVERSE (R) and a forward gear, spinning the
wheels as little as possible. Release the
accelerator pedal while you shift, and press lightly
on the accelerator pedal when the transaxle is
in gear. By slowly spinning the wheels in the
forward and reverse directions, you will cause a
rocking motion that may free your vehicle. If
that does not get your vehicle out after a few tries,
it may need to be towed out. If your vehicle
does need to be towed out, seeTowing Your
Vehicle on page 340.
Loading Your Vehicle
It is very important to know how much weight your
vehicle can carry. This weight is called the vehicle
capacity weight and includes the weight of all
occupants, cargo, and all nonfactory-installed
options. Two labels on your vehicle show how much
weight it may properly carry, the Tire and Loading
Information label and the Certication label.
{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
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