2009 PORSCHE 911 wheel

Operation, Safety
61
ABS Brake System
(Antilock Brake System)The ABS system represents a major contribution
to the enhancement of active safety in your vehi-
cle. This system prevents the wheels from locking
in a panic stop on almost all road surfaces.
With the ABS system in your vehicle, the
following areas are enhanced:
Steering, vehicle remains steerable under all
braking forces when ABS is engaged.
Good directional control, no swerving caused
by locking of wheels under braking conditions.
Shorter stopping distance, stopping distances
are usually reduced because controlled braking is
maximized.
Prevention of wheel lock up, no brake- induced
sliding and thus no localized tire wear from emer-
gency braking.
The crucial advantage of the ABS system over a
conventional brake system is in the area of main-
taining directional control and maneuverability of
the car in emergency situations.
Warning!
The increased control that is provided should
not induce you to take greater risks with your
safety. The limits dictated by the laws of
physics cannot be overcome, even with ABS.
The risk of accidents due to inappropriate
speed cannot be reduced, even by the ABS.
The driver bears the responsibility for all
driving maneuvers.
fAdapt your driving style to the prevailing road
and weather conditions.
fObey all traffic laws.
Other vehicles not equipped with the ABS
system may not be able to maintain control,
especially on wet or poor road surfaces and
thus may be more likely to impact you from
behind.
fTo minimize that risk, use your ABS system to
increase your ability to maneuver to avoid dan-
gerous situations and not merely to try to stop in the shortest distance possible.
Operation of the ABS systemA wheel speed sensor is mounted to each of the
four wheels. If wheel lock-up of either of the front
wheels or the rear wheels is sensed during brak-
ing, the brake pressure is adjusted automatically
until the wheel no longer slips.
If braking forces approach the wheel lock-up point
for all wheels (panic braking) the ABS system will
intervene to provide a rapid rythmic braking. The
proper operation of ABS is perceived by the driver
as a pulsating brake pedal in conjunction with au-
dible noise and perhaps some vibration.
fIf you experience these sensations while driv-
ing or a road surface with questionable trac-
tion, reduce vehicle speed appropriate for the
prevailing road conditions.
fIf full braking should be necessary, press the
brake pedal all the way down throughout the
entire braking procedure, regardless of the pul-
sating pedal. Do not ease up on pressure ap-
plied to the pedal.
The functional readiness of all the main electrical
components of the ABS is checked by an
electronic monitoring system both before and
while you drive.

Operation, Safety
63
Porsche Traction Management
(PTM)With PTM, the engine power is variably distributed
to the front and rear wheels.
Power distribution between the front and rear ax-
les is performed by a map-conrolled multiple-disc
clutch.
Distribution of the engine power also depends on
the difference in wheel speed between the two ax-
les.
The multiple-disc clutch always delivers sufficient
drive power to the front wheels to ensure optimum
propulsion even on an unfavorable road surface.
In combination with the Porsche Stability Manage-
ment (PSM), the PTM ensures optimum handling
and high driving stability.
Warning!
The increased control that is provided should
not induce you to take greater risks with your
safety. The limits dictated by the laws of phy-
sics cannot be overcome, even with PTM.
The risk of accidents due to inappropriate
speed cannot be reduced, even by PTM.
The driver bears the responsibility for all dri-
ving maneuvers.
fAdapt your driving style to the prevailing road
and weather conditions.
fObey all traffic laws.
Dynamometer testing procedure Some U.S. states and Canadian provinces con-
duct emissions inspection/maintenance testing in-
volving the use of two-wheel dynamometer.
A two-wheeled dynamometer is a treadmill type
device upon which a single axle of the car, the dri-
ving axle of the vehicle, rotates to simulate vehicle
operation on the road while the vehicle remains
stationary.
Your vehicle has a full-time four-wheel drive system
which cannot be disabled. Severe damage to the
powertrain can result if tested on a two-wheel dy-
namometer.
Warning!
Risk of severe powertrain damage and a pos-
sible unexpected movement of the vehicle.
fDo not test your vehicle on a two-wheel dyna-
mometer.
fAdvise the emission station of this warning be-fore testing the vehicle.
Brake testsBrake tests must be performed only on plate-type
test stands or roller test stands.
The ignition must be off.
The following limit values must not be exceeded
on roller test stands:
– Testing speed 5 mph (8 km/h)
– Test duration 20 seconds Handbrake tests Handbrake tests on the roller test stand must only
be carried out with the ignition switched off. Balancing wheels on the vehicle During finish balancing of the wheels, the vehicle
must be hoisted and all the wheels able to rotate
freely. Towing fPlease see the chapter “TOWING” on
Page 280.Wheels/TiresThe PTM control unit is adapted to the approved
tire sizes. The use of non-approved tire sizes may
lead to deviations in wheel speeds and it may influ-
ence handling or result in the PTM switching off.

66
Operation, Safety
Porsche Stability Management
(PSM)PSM is an active control system for stabilization of
the vehicle approaching the performance limits of
driving maneuvers.
Warning!
Risk of an accident, resulting in serious per-
sonal injury or death.
The increased control that is provided should
not induce you to take greater risks with your
safety. The limits dictated by the laws of
physics cannot be overcome, even with PSM.
The risk of accidents due to inappropriate
speed cannot be reduced, even by PSM.
The driver bears the responsibility for all
driving maneuvers.
fAdapt your driving style to the prevailing road
and weather conditions.
fObey all traffic laws.
Sensors at the wheels, brakes, steering system
and engine continuously measure:
–Speed
– Direction of travel (steering angle)
– Lateral acceleration
– Rate of turn about the vertical axis
– Longitudinal accelerationPSM uses these values to determine the direction
of travel indicated by the driver.
PSM intervenes and helps to correct the course if
the actual direction of motion deviates from the
chosen course (steering-wheel position):
It brakes individual wheels as needed. In addition,
the engine power may be manipulated in order to
stabilize the vehicle.
The events below inform the driver of PSM control
operations and warn him/her to adapt his/her
driving style to the road conditions:
– The multifunctional information light on the
instrument panel flashes.
– Hydraulic noises can be heard.
– The vehicle decelerates and steering-wheel
forces are altered as the PSM controls the
brakes.
– Reduced engine power.
– The brake pedal pulsates and its position is
changed during braking.
In order to achieve full vehicle deceleration,
foot pressure must be increased after the
brake pedal has begun vibrating.
Examples of PSM control operations– If the front wheels of the vehicle drift on a
bend, the rear wheel on the inside of the bend
is braked and the engine power is reduced if
necessary.
– If the rear of the vehicle swings out on a bend,
the front wheel on the outside of the bend is
braked.Additional braking functions– Pre-filling the brake system:
The brake system is prepared for possible
subsequent emergency braking if the acceler-
ator pedal is released suddenly and quickly.
The brake system is prefilled and the brake
pads are already applied gently to the brake
discs.
– Brake booster:
In the event of an emergency braking operation
where the pedal force is insufficient, a brake
booster provides the braking pressure neces-
sary for maximum deceleration at all 4 wheels.Advantages of PSM– Best possible traction and lane-holding ability
in all driving situations – even on road surfaces
with varying friction.

Operation, Safety
67
– The system compensates for undesired lateral
vehicle reactions when the driver releases the
accelerator pedal or brakes when cornering.
This compensation functions up to the
maximum lateral acceleration.
– PSM actively stabilizes the vehicle as required
during dynamic driving maneuvers (e.g. rapid
steering movements, during lane changes or
on alternating bends).
– Improved braking stability on bends and on
different or varying road surfaces.
– It improves braking function and shortens
stopping distance in the event of emergency
braking.Readiness for operationPSM is switched on automatically every time you
start the engine.
PSM should always be switched on during
“normal” driving.
However, it may be advantageous to switch off
PSM temporarily in exceptional situations, for
example:
– On a loose surface or in deep snow,
– When “rocking” the vehicle free and
– When using snow chains.
Switching off PSMfPress PSM OFF button.
PSM is switched off after a short delay.
The light-emitting diode in the button is lit up.
When the PSM is switched off, the PSM multi-
functional light on the instrument panel is lit
and a message is shown on the on-board
computer.
An acoustic signal also sounds.
Note
When PSM is switched off, the additional braking
functions are deactivated. Automatic reactivation
in emergency situations is linked to the PSM
control.The following functions stabilize the vehicle in
emergency situations, even with PSM switched
off:
– When PSM is off, the vehicle is stabilized as
soon as one of the two front wheels enters the
ABS control range.
– When PSM is off and Sport mode is on, the
vehicle is stabilized as soon as both front
wheels enter the ABS control range.
One-sided spinning of the wheels is prevented,
even with PSM switched off.
Switching PSM back onfPress PSM OFF button.
PSM is switched on after a short delay.
The light-emitting diode in the button and the
PSM multifunctional light on the instrument
panel go out.
The on-board computer shows a message.

68
Operation, Safety
Sport modeA sportier car set-up is obtained when Sport or
Sport Plus mode is switched on.
PSM interventions are later than in Normal mode;
the vehicle can be maneuverd with greater agility
at its performance limits, without dispensing with
the assistance of PSM in emergency situations.
This helps to achieve optimal lap times, particu-
larly on race circuits and a dry road surface.
– The multifunctional light on the instrument
panel lights up for a lamp check when the
ignition is switched on.
– The light indicates a control operation by
flashing, including when PSM is switched off
(brake control in the event of one-sided wheel
spin).
– In conjunction with a message on the on-board
computer, the light indicates that PSM is
switched off.
An acoustic signal also sounds.
– The light indicates a fault in conjunction with a
message on the on-board computer.
PSM is out of order.fPlease have the fault remedied at an author-
ized Porsche dealer.
fPlease see the chapter “PUTTING VEHICLE
INTO OPERATION” on Page 263.
TowingfPlease see the chapter “TOWING” on
Page 280.Checks on test standsBrake tests
Brake tests must be performed only on plate-type
test stands or roller test stands.
The ignition must be switched off.
The following limit values must not be exceeded
on roller test stands:
– Testing speed 5 mph (8 km/h)
– Test duration 20 seconds
Handbrake tests
Handbrake tests on the roller test stand must be
performed only with the ignition switched off.
PSM multifunctional light

Operation, Safety
69
PASM makes two running-gear setups available to
the driver: “Normal” and “Sport”.
The selection is made via a button on the center
console.
In Normal mode the running gear is in a comfort-
able setup.
Sport mode offers very sporty shock absorber
tuning.
The variable suspension system selects the appro-
priate damping level for each wheel according to
the situation and driving conditions.
Example:
If the vehicle is driven in a very sporty manner in
Normal mode, PASM automatically adapts the
shock-absorber behavior to the driving situation
accordingly.
Switching on PASM Sport modefPress PASM button in the center console.
When PASM Sport mode is switched on, the
light-emitting diode in the button is lit up and a
message is shown on the on-board computer.Switching off PASM Sport modefPress PASM button in the center console.
The light-emitting diode in the button goes out
and the on-board computer displays a
message.
After the ignition is switched off, PASM is
automatically reset to Normal mode.
Retractable Rear SpoilerThe rear spoiler improves driving stability,
especially at higher speeds.
Warning!
Risk of accident. If the rear spoiler cannot be
extended, driving stability will be adversely
affected by increased rear axle lift, which
could lead to loss of control.
fAdapt your driving style and speed to the
changed driving behavior.
fHave the fault remedied at an authorized
Porsche dealer.
Risk of injury during manual retraction or
extension of the rear spoiler with the vehicle
stationary.
fMake sure that no persons or objects are
within the range of movement of the rear
spoiler.
Risk of damage from pushing the vehicle by
the spoiler.
fDo not push the vehicle at the spoiler.
Porsche Active Suspension
Management (PASM)

Operation, Safety
75
Switch position 2Start engine
fTurn ignition key to ignition lock position 2.
fPlease see the chapter “STARTING PROCEDU-
RES” on Page 77.Switch position 3Ignition off
fTurn ignition key to ignition lock position 3.
Note on operation
The vehicle battery discharges if the ignition key is
left inserted.
If the vehicle battery is dead, the key can only be
pulled out of the ignition lock if the emergency
operation is performed:
fPlease see the chapter “EMERGENCY OPERA-
TION – PULLING OUT THE IGNITION KEY” on
Page 76.
Locking the steering columnAutomatic locking
The steering column is automatically locked when
the ignition key is withdrawn from the ignition lock.
Warning!
Risk of an accident, resulting in serious per-
sonal injury or death.
The steering wheel will lock and will cause
loss of steering.
fNever remove key from the ignition lock or turn
the key off while the vehicle is moving.
fAlways withdraw the ignition key when leaving the vehicle.Automatic unlocking
The steering column is unlocked when the vehicle
is unlocked with the radio remote control.
Note
fTo avoid discharging the battery, always re-
move the ignition key from the ignition lock.
Please see the chapter “BATTERY” on
Page 261.
Gong If you leave the key in the ignition/steering lock, a
gong will sound when the driver’s door is opened.
This is a reminder to remove the key.

78
Operation, Safety
Stopping Engine fTurn key back to position 3.
fDo not stop engine immediately after hard or
extended driving.
Keep engine running at increased idle for
about two minutes to prevent excessive heat
build-up before turning off engine.
fTo avoid discharging the battery, always re-
move the ignition key from the ignition lock.
fWhen leaving the car, always remove the igni-
tion key and apply the handbrake. Engage 1st
gear or reverse gear on vehicles with manual
transmission or move the selector lever to po-
sition P on vehicles with PDK transmission.
fEngage the steering lock by moving the steer-
ing wheel to the left or right.
Turn the steering wheel to the locking position
before you switch off the engine so that you
don’t have to exert yourself when locking or
unlocking the steering.
Warning!
Danger of injury. Hot engine compartment
components can burn skin on contact.
fBefore working on any part in the engine com-
partment, turn the engine off and let it cool down sufficiently.
Engine-compartment blower,
radiator fan The radiator and radiator fans are in the front of
the car.
The engine-compartment blower is mounted on
the engine compartment lid.
Warning!
Risk of injury.
After the engine is switched off, the engine-
compartment temperature is monitored for
approx. 30 minutes.
During this period, and depending on tem-
perature, the engine-compartment blower
may continue to run or start to run.
fCarry out work in these areas only with the en-
gine off, the ignition off, and exercise extreme
caution.
Risk of injury. The radiator fans in the front
end of the car may be operating or
unexpectedly start operating when the
engine is switched on.
fCarry out work in these areas only with the en-gine switched off.
Automatic garage door The ignition system in your Porsche may interfere
with your electronically operated garage door.
fTo check this, drive your Porsche close to the
garage door. Make sure not to interfere with
the operating range of the door.
fRun the engine at different speeds.
fIf the garage door opens or closes without you
operating the garage door unit in your car,
contact the dealer who installed the automatic
garage door to have the frequency and/or
coding of the garage door signal changed or
modified.