2005 PORSCHE 911 CARRERA engine

Controls, Instruments
51
fDo not add any additional coverings or stickers
to the steering wheel or in the area of the pas-
senger airbag, side airbags and head airbags.
Doing so may adversely affect the functioning
of the airbag system or cause harm to the oc-
cupants if the airbag system should deploy.
fDo not undertake any wiring for electrical ac-
cessory equipment in the vicinity of the airbag
wiring harnesses. Doing so may disable the
airbag system or cause inflation.
fIf the warning light comes on, the airbag sys-
tem should be repaired immediately by your
authorized Porsche dealer.
Note
Airbag components (e.g. steering wheel, door
trim, seats) may be disassembled only by an au-
thorized Porsche dealer.
When disposing of a used airbag unit, our safety
instructions must be followed. These instructions
can be obtained at any authorized Porsche dealer. Faults are indicated by a warning light in the instru-
ment panel and a message on the on-board com-
puter.
fIn the following cases you should immedi-
ately consult an authorized Porsche deal-
er in order to assure the airbag system is
functioning properly:
– If the warning light does not light up when the
ignition is switched on or
– If the warning light does not go out once the
engine is running or
– If the warning light appears while driving.
fPlease observe the chapter “WARNINGS ON
THE INSTRUMENT PANEL AND THE ON-
BOARD COMPUTER” on Page 105.
Warning light “PASSENGER AIRBAG OFF”fPlease observe the chapter “KEY-OPERATED
AIRBAG DEACTIVATION DEVICE” on Page 49.
Airbag maintenanceIn order to ensure long-term functioning, the air-
bag system must be inspected by an authorized
Porsche dealer at the intervals recommended in
your Maintenance booklet.
Important information
If you sell your Porsche, notify the purchaser that
the vehicle is equipped with airbags, and refer
them to the chapter, “Airbag Systems”, in the own-
er’s manual (safety and disposal rules).
Further information on the airbag system can be
found on labels on the sun visors, as well as on all
airbag components.
fFor special recommendations on the use of
child restraints:
Please observe the chapter “CHILD RES-
TRAINT SYSTEMS” on Page 46.
Warning light and warning
message

56
Controls, Instruments
Retractable Rear SpoilerThe rear spoiler reduces rear axle lift, particularly
at high 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 behaviour.
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.
Automatic modeThe limits for automatic extension and retraction
of the spoiler depend on various circumstances
(e.g. driving speed, engine compartment temper-
ature).
Engine compartment temperature
under 122°F/55°C
Spoiler extends at 75 mph/120 km/h and
retracts at 37 mph/60 km/h.
Engine compartment temperature
over 140°F/60°C
Spoiler extends at 50 mph/80 km/h and retracts
at 19 mph/30 km/h.
If automatic control fails, a warning message is
displayed by the on-board computer.

Controls, Instruments
61
Brake booster The brake booster assists braking only when
the engine is running.
When the car is moving while the engine is not run-
ning, or if the brake booster is defective, more
pressure on the brake pedal is required to bring
the car to a stop.
Moisture or road salt on brakes affects braking.
When the vehicle is driven on salted roads for ex-
tended periods, the brakes should be washed
down thoroughly about every 2 weeks. An auto-
matic carwash facility cannot do this job properly.
Brakes will dry after a few cautious brake applica-
tions.
Warning!
Driving through water may reduce the trac-
tion.
Moisture on brakes from road water, car
wash, or coating of road salt may affect
braking efficiency.
fCautiously apply brakes to test brakes after being exposed.
Brake wear Your car has excellent brakes, but they are still
subject to wear. The rate at which they wear de-
pends on how the brakes are used.
fHave the brake system inspected at the
intervals recommended in your Maintenance
Booklet.
If the warning lights in the instrument panel and on-
board computer stay on when the engine is run-
ning or come on while driving, the brake pads are
worn, excessively.
fDo not continue to operate the vehicle.
Have your authorized Porsche dealer inspect
or replace the brake pads.
Brake pads Wear on the brake pads and brake discs depends
to a great extent on the driving style and the con-
ditions of use and therefore cannot be expressed
in actual miles on the road.
The high-performance brake system is designed
for optimal braking effect at all speeds and tem-
peratures.
Certain speeds, braking forces and ambient
conditions (such as temperature and humidity)
therefore might cause “brake noises”.
New brake pads or linings
New brake pads and brake discs have to be “bro-
ken in”, and therefore only attain optimal friction
when the car has covered several hundred miles
or km.
The slightly reduced braking ability must be com-
pensated for by pressing the brake pedal harder.
This also applies whenever the brake pads and
brake discs are replaced.
Warning light USA
Warning light Canada

Controls, Instruments
63
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. The brake pressure
is regulated for each front wheel individually and
for both of the rear wheels together.
On a road surface which is slippery on only one
side, the rear wheel which is braking on the slip-
pery surface determines the brake pressure which
will be applied equally to both rear wheels. This en-
sures that directional stability is maintained. How-
ever, 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 audible 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.
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. When the ignition is switched on the ABS warning
light will light up while the system is electronically
interrogated and goes out when the engine is
started if the check is not yet complete.
If the ABS warning lamp fails to go out, this indi-
cates that ABS has been deactivated due to a
fault. If the warning lights in the instrument panel
and on-board computer light up while you are driv-
ing, this indicates that a fault has occurred. In both
cases, normal braking, as in vehicles without ABS,
is still retained.
The ABS system should, however, be examined at
an authorized Porsche dealer immediately to pre-
vent the occurrence of further faults.
fIf the ABS system becomes inoperative, take
your vehicle to your authorized Porsche dealer
immediately.
Warning!
The control unit of the ABS brake system is
set for standard tire size. If non-standard
tires are installed, the control unit may mis-
interpret the speed of the vehicle, because of
the variant data it receives from the sensors
on the axles.
fUse only tire makes and types tested by Porsche.
Warning light USA
Warning light Canada

64
Controls, Instruments
Sport ModeA sportier car set-up is obtained when Sport mode
is switched on. Interventions by the Porsche
control systems are intentionally shifted towards
greater agility and driving performance.
– PASM (Porsche Active Suspension Manage-
ment) is automatically changed to Sport mode,
resulting in a stiffer suspension setup.
– The Tiptronic S switches to a sporty gear-
changing map and shortens the gear shifting
periods. Gear changes take place faster.
– PSM (Porsche Stability Management) control is
sporty. PSM interventions take place later than
in Normal mode. The driver can maneuver the
vehicle with greater agility at its performance
limits, without having to dispense with the
assistance of PSM in emergency situations.
– The electronic accelerator pedal reacts
sooner, and the engine is more responsive to
throttle inputs. When Sport mode is switched
on, this function is activated only after the
driver has floored the accelerator pedal or
released it briefly.
– The rpm limiter characteristic is “harder”, i.e.
the engine is immediately throttled when the
performance limits are reached (only in manual
selection mode for vehicles with Tiptronic S).
fPlease observe the appropriate chapters of
this Manual.
Switching Sport mode on and offfPress SPORT button in the center console.
When Sport mode is switched on, the light-
emitting diode in the SPORT button is lit.When Sport mode is switched on, the logo SPORT
appears next to the digital speedometer.
Switching Sport mode on and off simultaneously
activates and deactivates the Sport mode of the
PA S M .
If the Sport mode of the PASM was activated with
the PASM button, it will remain on.
After the ignition is switched off, Sport mode is
automatically reset to Normal mode.

Controls, Instruments
65
Porsche Stability Management
(PSM)PSM is an active control system for stabilization of
the vehicle during extreme driving manoeuvres.
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 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. Advantages of PSM – Superior traction and lane-holding ability in all
driving situations – even on road surfaces with
varying friction.
– PSM actively stabilizes the vehicle during dy-
namic driving maneuvers (e.g. rapid steering
movements, during lane changes or on alter-
nating curves).
– Improved braking stability in curves and on dif-
ferent or varying road surfaces.
Readiness for operationPSM is switched on automatically every time you
start the engine.FunctionSensors at the wheels, brakes, steering system
and engine continuously measure:
–Speed
–Steering angle
– Lateral acceleration
– Rate of turn about the vertical axis
– Brake pressure
PSM uses these values to determine the direction
of travel desired by the driver.
PSM intervenes and corrects the course if the
actual direction of motion deviates from the
desired 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 to adapt his driving style
to the road conditions:
– The multi-functional information light on the
instrument panel lights up.
– 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 begin-
ning the brake pedal pulsing.
f f f

66
Controls, Instruments 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.
The 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
Switching off PSMfPress PSM OFF button.
PSM is switched off after a short delay.
The light-emitting diode in the button is illumi-
nated.
When the PSM is switched off, the multifunc-
tional PSM light on the instrument panel is lit
and a message is shown by the on-board
computer.
An acoustic signal also sounds.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
multifunctional PSM light go out.
The on-board computer shows a message.

68
Controls, Instruments The previously selected PASM mode is always ac-
tivated after the engine is started.
There is no automatic return to normal mode after
the ignition is switched off.
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 sporty and
comfortable setup.
Sport mode offers a markedly sporty shock
absorber tuning (e.g. for driving on the race
circuit).
The variable suspension system selects the appro-
priate damping level for each wheel according to
the situation and conditions of driving.
Example:
If the vehicle is driven in a markedly sporty manner
in Normal mode, PASM automatically adapts the
shock-absorber behavior to the driving situation in
this case as well.
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 illuminated
and a message is shown by 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.
Porsche Active Suspension
Management (PASM)