brake sensor PORSCHE CAYNNE 2008 1.G Information Manual

Drive
The convenience of an automatic.
The excitement of a sequential gearbox.
Six-speed Tiptronic S.
Each gearshift point is automatically
selected based on current road
conditions and driving style.
Within a short space of time,
you’ll develop a feel for the
system and begin to influence
gearshifts using the throttle alone.
The benefits of Tiptronic S are most
apparent in high-performance driving.
The immediacy of response, with
practically no interruption in drive,
is comparable with that of a manual
gearbox.
Tiptronic S automatically selects
the optimum gearshift pattern,
even in low-range mode. The
low-range gearing is available at
speeds of up to 15 km / h (9 mph).
You can also return to high-range
mode at up to 30 km / h (19 mph).
For complete manual control,
simply slot into manual and use
the gearshift controls on the
steering wheel. If you prefer, you
can use the gear selector lever
on the centre console. Even in
automatic mode, you can change
gear manually via the rocker
controls on the steering wheel.
If there is no further manual
input for a period of 8 seconds,
the system reverts to automatic
mode.
One of the special features in
Tiptronic S is standby control.
When the car is stationary in an
active gear position and with the
foot brake applied, the input
clutch automatically disconnects
the engine from the driveline,
thereby reducing fuel consumption.
Other useful functions include
a warm-up programme which
temporarily suppresses upshifts
in order to accelerate warm-up
in the catalysts and thus reduce
emissions. If rapid throttle inputs
are detected, the system automat-
ically selects the ‘Sport’ gearshift
pattern, i.e., there is no need to
use a ‘kickdown’ function. When
the throttle is released quickly, e.g.,
on entering a corner, unwanted
downshifts are prevented.
Mid-corner gearshifts are also
suppressed, enhancing stability
and safety.Under heavy braking, Tiptronic S
shifts down to maximise engine
braking. An incline sensor enables
better uphill acceleration and
better engine braking on descent.
Another special feature, Porsche
Hill Holder, permits easy hill starts
without the need to use the brakes.
The gearbox cooling system is
specifically designed to match
the performance, transport,
towing and off-road capabilities
of all Cayenne models.
Tiptronic S is standard equipment
on the Cayenne Turbo and optional
on the other three models. The
six forward ratios transmit power
with smoothness, efficiency and
precision – whatever your choice
of terrain.
In automatic mode, the gearshift
maps range from maximum
economy to maximum performance.
Tiptronic S gearshift control on steering wheel
Tiptronic S gear selector
· 65 · · 64 ·

Chassis
Active damping adjustment for optimum performance and comfort.
Porsche Active Suspension Management (PASM).
Both systems are optional on
the Cayenne and Cayenne S. The
Cayenne GTS has an exclusive
combination of PASM and high-
performance steel-sprung suspen-
sion (ride height lowered by 24 mm).
During performance driving or
heavy off-road use, there is a
greater tendency for the body
to roll. PASM prevents this from
happening, thereby improving
stability and occupant comfort.
PASM has three setup modes:
‘Comfort’, ‘Normal’ and ‘Sport’.
In all three cases, the system
uses a series of sensors to
monitor the movement of the
body, e.g., under acceleration and
braking or on poor road surfaces.
It also gathers data on lateral
acceleration, steering angle, brake
pressure and engine torque. The
PASM control unit then evaluates
this information and modifies the
damping forces in accordance
with the selected mode.
PASM remains active at
all times, adapting to the
changing conditions.
If the road surface deteriorates
while travelling in ‘Sport’ mode,
for instance, the system
immediately changes to a softer
rating, thereby improving road
contact. When the road surface
improves, PASM automatically
reverts to the original, harder
rating. This not only increases
stability and safety, it also
enhances comfort.
PASM is an electronic damping
control system. It offers continuous
adjustment of individual damping
forces based on current road
conditions and driving style. PASM
is standard on the Cayenne Turbo
in conjunction with air suspension.
· 77 · · 76 ·PASM control with ‘Comfort’, ’Normal’ and ‘Sport’ options

by a tandem booster and large
brake master cylinder. The foot-
operated parking brake uses a
duo-servo system mounted on
each of the rear discs.
Porsche Stability Management
(PSM) features two additional
brake functions: electronic brake
Porsche braking systems are
renowned worldwide as the
benchmark in performance and
stability. The Cayenne models
continue this tradition, offering
excellent deceleration – even
when fully laden with five adult
Porsche has always been synonymous with acceleration.
That’s only half the story.
Braking system.
All Cayenne models have internally
vented discs all round. This simple
yet highly effective design ensures
consistent brake performance.
The front disc dimensions
(diameter/thickness) are 330 mm /
32 mm on the Cayenne, 350 mm /
34 mm on the Cayenne S and
Cayenne GTS, and 380 mm /
38 mm on the Cayenne Turbo.
All models have six-piston monobloc
aluminium brake calipers at the
front and four-piston equivalents
at the rear. The Cayenne Turbo
has a new and more powerful
braking system to offset its higher
performance. The fixed calipers on
the Cayenne Turbo are noticeably
larger and have a striking red
paint finish. The calipers on the
Cayenne GTS are also red, while
the Cayenne S has silver and the
Cayenne black. Braking is assisted
Safety
occupants, a full complement of
luggage and a braked trailer load
of up to 3,500 kg (Cayenne GTS
with steel-sprung suspension:
3,080 kg).
prefill prior to an emergency stop
and all-wheel brake assist. See
page 98 for more information
on PSM.
All brake pads are fitted with
individual wear sensors. When new
pads are required, a warning light
is illuminated in the instrumentcluster. The brake lines serving
each of the rear calipers feature
special off-road protection
against rocks and other debris.
· 95 · · 94 · Cayenne: standard front brake
with 330-mm discCayenne S: standard front brake
with 350-mm disc
Cayenne GTS: standard front brake
with 350-mm discCayenne Turbo: new standard front brake
with 380-mm disc

Oversteer with PSM
Understeer without PSM
Car steers
off line Car steers
off line PSM corrects
line and
stabilises car
PSM corrects
line and
stabilises car
Understeer with PSM Oversteer without PSM
All Cayenne models are
equipped with Porsche Stability
Management (PSM) as standard.
This electronic control system
uses a range of functions –
including anti-lock braking (ABS) –
to help stabilise the vehicle
(and trailer, if fitted) in hazardous
road scenarios. Throughout each
journey, PSM uses a range of
sensors to monitor the direction,
speed, yaw velocity (speed of
rotation around the vertical axis)
and lateral acceleration of the
car. The system then calculates
the actual direction of travel. If
the car begins to oversteer or
understeer, PSM applies selective
braking on individual wheels to
restore stability. If necessary,
PSM can also intervene in the
engine management system to
temporarily modify the amount
of drive to the wheels.PSM has two additional functions
that help reduce braking distances.
If the throttle pedal is released
suddenly, PSM automatically
readies the braking system. The
pressure in the brake lines is
marginally increased, bringing
each of the pads into light contact
with the corresponding disc. If the
driver goes on to apply the brakes,
the calipers respond more quickly.
In an emergency stop – i.e., when
the pressure on the brake pedal
exceeds a certain threshold –
the brake assist function uses
the PSM hydraulics to apply
maximum braking force at all
four wheels.
PSM makes a significant contribu-
tion to car and trailer safety –
within the laws of physics. It
compensates for load transfer
caused by throttle and brake
inputs up to the maximum degree
of lateral acceleration. It also
enhances the car’s driving dynam-
ics and directional stability when
accelerating on variable road
surfaces. PSM can also intervene
through the locking centre and
axle differentials as part of
Porsche Traction Management
(PTM).
Other features include a
special control strategy in
the PSM-integrated ABS for braking on loose surfaces such
as gravel or snow. By briefly
locking the wheels, a wedge is
formed ahead of each tyre which
provides additional purchase
to help slow the car.
For a more active driving experi-
ence, PSM can also be disabled.
For safety reasons, it remains
active in the background, ready
to intervene in critical scenarios.
Expecting the best means preparing for the worst.
Porsche Stability Management (PSM).
Safety
· 99 · · 98 ·

Wiper system and rain sensor.
The front wiper system has two
fixed speeds and an automatic
rain sensor function. Washer fluid
is delivered via two heated jets,
ensuring uniform coverage of the
entire windscreen area.
The rear wiper system is also
designed for maximum visibility
in all conditions. The rear washerjet is located on the roof spoiler,
close to the third brake light.
ParkAssist.
This optional parking aid
(standard on Cayenne Turbo)
uses an acoustic signal and
visual distance displays to warn
of obstacles at the front or rear.
A total of 12 sensors are neatly
concealed in the front and rear
aprons.
The front and rear LED displays
are located on the dashboard
and rear rooflining, respectively.
An intermittent warning tone
increases in rapidity as the
obstacle is approached.
Reversing camera.
The optional reversing camera
provides high-resolution, high-
contrast colour pictures. The
system is particularly useful
during parking manoeuvres or
when preparing to fit a trailer.
After use, the camera is automat-
ically retracted to protect the lens.
Rain sensorReversing camera retracted
Reversing camera display in new PCM
Combining comfort with safety.
Comfort
Reversing camera extended
· 125 · · 124 ·