2005 PORSCHE CAYENNE S Pressure

66
Controls, Safety, Instruments
Brake system functionYour Porsche is equipped with a power assisted
hydraulic dual circuit brake system with disc
brakes at the front and rear.
Both circuits function independently. One brake
circuit operates the front left and rear right wheel
and the other operates the front right and rear left
wheel.
If one brake circuit has failed, the other will still op-
erate. However, you will notice an increased pedal
travel when you apply the brakes.Failure of one
brake circuit will cause the stopping distance to in-
crease.
Warning!
Risk of an accident. In the unlikely event of
hydraulic failure of one brake circuit:
fPush the brake pedal down firmly and hold it in
that position. A mechanical linkage activates
the second circuit, and you will be able to bring
the vehicle to a stop.
fAfter bringing your vehicle to a complete stop,
avoid driving the vehicle and instead have it
towed to the nearest authorized Porsche deal-er for repair.The warning light in the instrument panel lights up.
A message will be displayed on the multi-purpose
display of the instrument panel if the brake fluid
level is too low, or (if the brake pedal travel has in-
creased) one of the two brake circuits has failed.
A greater braking pressure will be required, stop-
ping distances will be longer and the braking be-
havior will change, particularly in curves.
With correctly adjusted brakes and a correctly
working brake system, the pedal travel to the
point of brake application should be 1-3/16 in. to
1-9/16 in. (30 to 40 mm). Whenever the brake
pedal travel exceeds this value, have the brake
system checked.
Brake warning light USA
Brake warning light
Canada

Controls, Safety, Instruments
67
Brake pedal
Warning!
Risk of an accident.
Any obstruction of the brake pedal could in-
crease the stopping distance.
fAlways check the movement of the brake pedal
before driving and make sure that it is not ob-
structed by a floor mat or any other object.
fSecure the floor mat to prevent it from sliding
into positions that could interfere with the safe
operation of your vehicle.
Your Porsche dealer will be glad to offer you
floor mats of the correct size including a secur-ing possibility.
Note
In case one of the two brake circuits fails, in-
creased pedal travel is required to bring your vehi-
cle to a full stop.
Warning!
To avoid overheating and premature wear of
the brakes:
fBefore descending a steep grade, reduce
speed and shift the transmission into a lower
driving position to control speed.
fDo not “ride the brakes“ by resting your foot on
the pedal when not intending to apply brake
pressure.
fDo not hold the pedal down too long or too of-
ten. This could cause the brakes to get hot and not function properly.
Brake boosterThe 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, road salt or grit on brakes affects brak-
ing. When the vehicle is driven on salted or gritted
roads for extended periods, the brakes should be
washed down thoroughly about every 2 weeks. An
automatic carwash facility cannot do this job prop-
erly. Brakes will dry after a few cautious brake ap-
plications.
Warning!
Driving through water may reduce the trac-
tion. Moisture on brakes from road water, car
wash, or a coating of road salt or grit may af-
fect braking efficiency.
fCautiously apply brakes to test brakes after being exposed.

Controls, Safety, Instruments
69
Warning!
fDo not obstruct the pedal travel with floor mats
or other objects.
The brake booster is ready for operation only
while the engine is running.
If the engine is switched off or there is a defect in
the brake booster, much greater force has to be
applied to the pedal when braking.
fPlease observe the chapter “TOWING” on
Page 350.
In heavy rain, while driving through water or after
leaving a car wash, the braking action may be de-
layed and increased pressure may be required.
fFor this reason, keep further back from the ve-
hicle in front and “dry” the brakes by applying
them at intervals. Make sure that following traf-
fic is not affected.
After a long drive over salted or gritted roads, a
coating may form on the brake discs and pads
that significantly reduces friction and thus braking
action.
fTherefore, clean the brake discs and pads ap-
prox. every 2 weeks with a strong jet of water.
The cleaning effect of automatic car washes is
insufficient.
To prevent corrosion of the brake discs, “brake
them dry” before parking the car.fEven though the brake discs consist of alloyed
grey cast iron, they will unavoidably start to
corrode if your car is parked for an extended
period. The brakes will tend to “rub” as a re-
sult.
The nature, extent and effects of corrosion de-
pend on the amount of time the vehicle was
parked, whether road salt or grit was spread
and whether grease-dissolving agents were
used in car washes.
If the braking comfort is noticeably impaired,
we recommend having the brake system
checked by experts at an authorized Porsche
dealer.
fTo relieve the braking system on downhill
stretches, change down to a lower gear in
good time to obtain engine braking.
If engine braking is insufficient on steep
stretches, operate the footbrake at intervals.
Continuous braking overheats the brakes and
reduces the braking effect.
fPlease observe the chapter “BRAKE-FLUID LE-
VEL” on Page 251.

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Controls, Safety, Instruments
Instrument Panel USA ModelsWarning and indicator lights on the
tachometer
Indicator lights in central instrument
panelWarning and indicator lights on the
speedometer
A Oil temperature gauge
BTachometer
CClock
D Clock reset button
E Cooling system temperature gauge
F Multi-purpose display
G Fuel gauge
H Reset button for trip counter display
I Speedometer
J Mileage displays
KVoltmeter Emission Control warning light
(Check Engine)
Airbag warning light
Safety belt warning light
PSM warning light
ABS warning light
Cruise control readiness
Disengageable anti-roll bars
Indicator light
Turn signal light, left
Indicator light
Turn signal light, right
Indicator light
Trailer turn signal
Indicator light
Rear fog light indicator light
Tire pressure warning light
Differential locking indicator light
Brake warning light
Fog light indicator light
General warning
Observe warning message on the multi-
purpose display!
High beam indicator light

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Controls, Safety, Instruments
Instrument Panel Canada ModelsWarning and indicator lights on the
tachometer
Indicator lights in central instrument
panelWarning and indicator lights on the
speedometer
A Oil temperature gauge
BTachometer
CClock
D Clock reset button
E Cooling system temperature gauge
F Multi-purpose display
G Fuel gauge
H Reset button for trip counter display
I Speedometer
J Mileage displays
KVoltmeter Emission Control warning light
(Check Engine)
Airbag warning light
Safety belt warning light
PSM warning light
ABS warning light
Cruise control readiness
Disengageable anti-roll bars
Indicator light
Turn signal light, left
Indicator light
Turn signal light, right
Indicator light
Trailer turn signal
Indicator light
Rear fog light indicator light
Tire pressure warning light
Differential locking indicator light
Brake warning light
Fog light indicator light
General warning
Observe warning message on the multi-
purpose display!
High beam indicator light

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Controls, Safety, Instruments
Multi-Purpose Display
Warning!
There is a danger of accident if you set or
operate the on-board computer, radio, navi-
gation system, telephone or other equipment
when driving.
This could distract you from the traffic and
cause you to lose control of the vehicle.
fOperate the components while driving only if
the traffic situation allows you to do so safely.
fCarry out any complicated operating or setting procedures only with the vehicle stationary.
It is not possible to describe all details of the
functions in this Owner's Manual.
The examples clearly demonstrate the functional
principle and clarify the menu structure.
As a rule, you can use the menu items:
MAIN MENU > SETTINGS > FACTORY SETTINGS
to return to the basic factory settings.
fPlease observe the chapter “FACTORY SET-
TINGS” on Page 107.
Readiness for operation– Ignition is on.Operation, controlsThe multi-purpose display is operated with the
rocker switch at the end of the wiper stalk and the
RESET switch at the bottom of the wiper stalk.
To move up in the menu
fPress rocker switch up.
To move down in the menu
fPress rocker switch down.To call selected menu line
fPress RESET switch.
To scroll in the menu
Arrows at the top and bottom of the menu indicate
additional entries.
fPress rocker switch up or down.
In the COMFORT menu, the menu scrolls
automatically as you approach the end of the list.
Note on operation
Depending on the equipment of your vehicle,
some information or functions may not be avail-
able on the multi-purpose display (e.g. navigation,
audio system, compass or tire pressure).

Controls, Safety, Instruments
81
Basic ScreensThe following basic screens are available once the
ignition has been switched on:
– Main menu
– Range on remaining fuel
–Average speed
– Navigation
– Tire pressure
–Compass
Note on operation
Depending on the equipment of your vehicle,
some information or functions may not be avail-
able on the multi-purpose display (e.g. navigation,
compass, audio system or tire pressure).
Information in the basic screenThe selected basic screen shows the following:
–Top display A:
Audio information (e.g. station, frequency, CD)
–Centre display B:
Information about range on remaining fuel,
average speed, compass, navigation, tyre
pressure, or access to main menu
–Bottom display C:
Outside temperature indicator
(except for compass, navigation, and tyre
pressure)
Changing basic screensfOperate the rocker switch.Resetting basic screensThe values can be reset to zero in the basic
screens for average speed.
fPress RESET switch for longer than 1 second.
The value is cleared.

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Controls, Safety, Instruments
General informationRange on remaining fuel
The range on remaining fuel is continuously
recomputed while driving based on fuel level,
current consumption and average consumption.
Average speed
The displayed values are based on the distance
travelled since the last reset to “zero”.
Note on operation
Switching the ignition off does not reset the
measurements. Values can thus be collected over
long periods. Disconnecting the vehicle battery
clears the memories.
Further on-board computer functions can be dis-
played in the PCM.
Please follow the separate operating instructions
for PCM.
Main MenufOperate the rocker switch until the basic
screen MAIN MENU is displayed.
fPress RESET switch.The submenus are listed:
– MPH limit
– Vehicle info
– Tire pressure
– Settings
Note
It is possible to leave the main menu via the BACK
command at any time by confirming the RESET
switch.