63 Instruments and controls
The ESP
® indicator light is located in the
tachometer and will be illuminated when the
ESP
® regulation is occurring, i.e. when
there is insufficient traction between the
tires and the road surface to provide the grip
required for the acceleration called for. The
driver can also sense that the engine is not
responding normally to the accelerator.
Operation of the ESP
® indicates reduced
traction between the tires and the road, and
that extra care should be taken by the driver.
In normal driving, the ESP
® system will help
to improve both ride comfort and safety, but
must not be regarded as a system to enable
the driver to drive at or maintain a higher
rate of speed. The same precautions for
safe cornering and driving on slippery roads
must still be applied (see page 163).The indicator light goes on when the system
is switched off with the ESP
® button.
IMPORTANT: the system is automatically
engaged every time the engine is started
(see page 163).
The indicator light also goes on when there
is a fault in the system. In this case the light
cannot be turned off by means of the ESP
®
button. If a fault is indicated, have the
system checked by an authorized Saab
dealer.
See also Electronic Stability Program
(ESP
®) on page 163.
ESP
® system, indicator
ESP
® system, OFF-indica-
tor
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163 Starting and driving
Electronic Stability
Program (ESP
®)
The system employs both the antilock brak-
ing system (ABS) and the traction control
system (TCS). It is a system that helps the
driver to stabilize the car in unusual circum-
stances that would otherwise be more diffi-
cult to handle.
How the ESP
® system works
The system can help to prevent the car from
skidding by braking one or several wheels
independently of the driver. The engine
output is then also reduced to prevent the
driving wheels from spinning. The car has
sensors that measure wheel speed, yaw
acceleration, lateral acceleration, steering
wheel position and braking pressure. The
values provided by these sensors are used
to calculate the actual direction of the car. If
this direction does not agree with that
intended by the driver, calculated from the
steering wheel position, the ESP
® is
engaged.
The ESP
® system improves the driver’s
chances of retaining control over the car in
critical situations.
To ensure that the system works as
designed, the dimensions of all four tires
must be the same.
WARNING
When driving normally, the ESP
® system
will help to improve the stability of the car.
This does not mean that car can be driven
faster. The same care and prudence as
normally applied should be displayed on
cornering and when driving on slippery
roads.
IB1841
Increased stability with ESP
®.
The system applies the brakes to the
wheels as shown in order to reduce the
likelihood of the car skidding
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226 Car care and technical informationUniform Tire Quality GradingQuality grades can be found where applica-
ble on the tire sidewall between tread shoul-
der and maximum section width. For exam-
ple:
Treadwear 200 Traction AA
Temperature A
The following information relates to the
system developed by the United States
National Highway Traffic Safety Administra-
tion, which grades tires by treadwear, trac-
tion and temperature performance. (This
applies only to vehicles sold in the United
States.) The grades are molded on the side-
walls of most passenger car tires. The Uni-
form Tire Quality Grading system does not
apply to deep tread, winter-type snow tires,
space-saver or temporary use spare tires,
tires with nominal rim diameters of 10 to 12
inches (25 to 30 cm), or to some limited-pro-
duction tires.
While the tires available on General Motors
passenger cars and light trucks may vary
with respect to these grades, they must also
conform to federal safety requirements and
additional General Motors Tire Perfor-
mance Criteria (TPC) standards.Treadwear
The treadwear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled conditions on
a specified government test course. For
example, a tire graded 150 would wear one
and a half (1.5) times as well on the govern-
ment course as a tire graded 100. The rela-
tive performance of tires depends upon the
actual conditions of their use, however, and
may depart significantly from the norm due
to variations in driving habits, service prac-
tices and differences in road characteristics
and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades repre-
sent the tire’s ability to stop on wet pave-
ment as measured under controlled condi-
tions on specified government test surfaces
of asphalt and concrete. A tire marked C
may have poor traction performance. Warn-
ing: The traction grade assigned to this tire
is based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.Temperature – A, B, C
The temperature grades are A (the highest),
B, and C, representing the tire’s resistance
to the generation of heat and its ability to dis-
sipate heat when tested under controlled
conditions on a specified indoor laboratory
test wheel. Sustained high temperature can
cause the material of the tire to degenerate
and reduce tire life, and excessive temper-
ature can lead to sudden tire failure. The
grade C corresponds to a level of perfor-
mance which all passenger car tires must
meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades B and A
represent higher levels of performance on
the laboratory test wheel than the minimum
required by law.
Warning: The temperature grade for this tire
is established for a tire that is properly
inflated and not overloaded. Excessive
speed, underinflation, or excessive loading,
either separately or in combination, can
cause heat buildup and possible tire failure.95_U S _M 07.book Page 226 Friday, June 9, 2006 8:58 AM
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228 Car care and technical informationTire Chains
Notice:
If your vehicle does not have
225/45R17 alt. 235/45 R17 size tires, use
tire chains only where legal and only
when you must. Contact your Saab
dealer regarding suitable snow chains.
Install them on the front tires and tighten
them as tightly as possible with the ends
securely fastened. Drive slowly and
follow the chain manufacturer’s instruc-
tions. If you can hear the chains contact-
ing your vehicle, stop and retighten
them. If the contact continues, slow
down until it stops. Driving too fast or
spinning the wheels with chains on will
damage your vehicle.If a Tire Goes Flat
It’s unusual for a tire to “blow-out” while
you’re driving, especially if you maintain
your tires properly. If air goes out of a tire,
it’s much more likely to leak out slowly. But
if you should ever have a “blow-out”, here
are a few tips about what to expect and what
to do:
If a front tire fails, the flat tire will create a
drag that pulls the vehicle toward that side.
Take your foot off the accelerator pedal and
grip the steering wheel firmly. Steer to main-
tain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blow-out, particularly on a curve, acts
much like a skid and may require the same
correction you’d use in a skid. In any rear
blowout, remove your foot from the acceler-
ator pedal. Get the vehicle under control by
steering the way you want the vehicle to go.
It may be very bumpy and noisy, but you can
still steer. Gently brake to a stop – well off
the road if possible.
If a tire goes flat, the next part shows how to
use your jacking equipment to change a flat
tire safely.
WARNING
If your vehicle has 225/45 R17 alt. 235/45
R17 size tires, don’t use tire chains,
there’s not enough clearance.
Tire chains used on a vehicle without the
proper amount of clearance can cause
damage to the brakes, suspension or
other vehicle parts. The area damaged by
the tire chains could cause you to lose
control of your vehicle and you or others
may be injured in a crash.
Use another type of traction device only if
its manufacturer recommends it for use
on your vehicle and tire size combination
and road conditions. Follow that manu-
facturer’s instructions. To help avoid
damage to your vehicle, drive slowly,
readjust or remove the device if it’s con-
tacting your vehicle, and don’t spin your
wheels.
If you do find traction devices that will fit,
install them on the front tires.95_U S _M 07.book Page 228 Friday, June 9, 2006 8:58 AM
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