2005 PORSCHE CAYENNE S Pressure

Shifting Gear, Traction Systems
205
D - Automatic selection mode (in the road
driving program)The functions of selector lever positions Dand M
differ in the on-road program, High Range, and in
the off-road program, Low Range.
fUse selector lever position D for “normal” driv-
ing.
The gears are shifted automatically according
to the accelerator position and speed.
Depending on the way the vehicle is driven and on
the resistance (e.g. uphill), the gear-changing
points are shifted towards higher or lower engine-
speed ranges. Movement of the accelerator,
driving speed, longitudinal and lateral acceleration
and the road profile all have an influence on the
gear-changing characteristic.
When PSM is switched off, transmission gear
changes are done at higher engine speeds.
Unwanted upward shifts, e.g. before bends, are
prevented by swiftly releasing the accelerator ped-
al.
Depending on lateral acceleration, upward chang-
es on bends are not made until the engine-speed
limit is reached.
During braking, and depending on the amount of
deceleration, the Tiptronic changes down earlier.
For subsequent cornering, the right gear is en-
gaged when pressure is applied to the brakes be-
fore the bend.The bend is taken in the right gear, and when you
accelerate out of the bend you do not have to
change down.
Moving off
In 2nd gear, the vehicle moves off with the throttle
only slightly open. Move off in 1st gear with the
throttle open wider or when the engine is cold.
When PSM is switched off, the car generally
moves off in 1st gear.
Shifting gear on the steering wheel
By shifting gear with the rocker switches on the
steering wheel, you can temporarily change from
automatic selection mode D to manual selection
mode M.
Advantages
– Shifting down before bends and on entering
built-up areas.
– Shifting down on downward slopes (engine
braking).
– Shifting down for brief spurts of acceleration.
– Selecting 1st or 2nd gear for moving off.
The manual selection mode remains engaged:
– For cornering (depending on the lateral accel-
eration) and overrunning,
– When the vehicle is stationary (e.g. at a junc-
tion).The system leaves manual selection mode:
– automatically after around 8 seconds
(unless car is cornering, overrunning or
stationary),
– if you depress the accelerator to kickdown.
Temporary change-down
Precondition
– Speed is higher than approx. 33 mph
(54 km/h).
fDepress accelerator quickly.
The Tiptronic changes temporarily to the sport-
iest gear-changing map, i.e. to the highest pos-
sible gear-changing points. Correspondingly,
the transmission shifts down immediately by
one, two or three gears.
Ending the function
fRelease the accelerator markedly (by approx.
25%).
f f f

Shifting Gear, Traction Systems
217
Power-Transmission and Running-Gear Control SystemsA complex interconnection of all control systems acting in power transmission and in the running gear has been realised in your Porsche.
All control systems have been linked with the aim of combining the best possible driving performance with maximum safety.
The following systems are involved:
System/designation Scope
PTM
Porsche Traction Management– Full-time all-wheel drive
– Electronically controlled center differential lock
– Automatic brake differential (ABD)
– Traction control system (TCS)
– Reduction gear/Low Range
PTM Plus
Porsche Traction ManagementIn addition to the PTM features, PTM Plus also includes:
– Electronically controlled rear differential lock
– Hydraulically disengageable anti-roll bars
PSM
Porsche Stability Management– Stability management system
– Anti-lock brake system (ABS)
– Traction control system (TCS)
– Automatic brake differential (ABD)
– Engine drag torque control (MSR)
Air suspension
with level control and height adjustment– Fully load bearing air spring struts with integral shock absorbers
– Air supply system with pressure accumulator
PAS M
Porsche Active Suspension Management– Shock absorber system with adaptive, continuous shock absorber control

Shifting Gear, Traction Systems
221
The events below inform the driver of PSM control
operations and warn him to adapt his driving style
to the road conditions:
– The information light in 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.
However, it is possible at any time to achieve
full vehicle deceleration by increasing the foot
pressure slightly.
Examples of PSM control operations
–Vehicle understeers:
If the front wheels of the vehicle drift on a
bend, engine power is reduced and the rear
wheel on the inside of the bend is braked if
necessary.
–Vehicle oversteers:
If the rear of the vehicle swings out on a bend,
the front wheel on the outside of the bend is
braked.Combined use of PSM and PTM/PTM Plus
In order to ensure optimal stabilisation of the
vehicle, the center differential lock (PTM) and
possibly the rear differential lock (PTM Plus) are
also opened when PSM interventions occur.
Tip on driving
When PSM is switched off, wheel-specific brake
interventions and the traction control system
(TCS) are also inactive.
The automatic brake differential (ABD) remains on.Off-road PSM
(PSM in Low Range program)
When Low Range is active, an off-road PSM
specially matched to off-road driving is activated
to enhance traction.
At a speed below 22 mph (35 km/h), the terrain
PSM intervenes later if the vehicle should under-
steer and thereby improves steerability in Low
Range.
If the brakes are highly stressed, the automatic
brake differential (ABD) switches itself off to
protect the brakes. It remains deactivated until the
brake system has cooled sufficiently.
Engine drag torque control
In conditions of excessive slip, the engine drag
torque control system prevents all driven wheels
from locking up when the car is overrunning. This
is also the case for downshifts on a slippery road.

228
Shifting Gear, Traction Systems
Driving systems for off-road drivingSpecially adapted driving programs or power-
transmission and running-gear control systems
are available for off-road driving:
– Off-road program Low Range
–Off-road PSM
–Off-road ABS
– Center differential lock
– Rear differential lock
fPlease observe the chapter “POWER-TRANS-
MISSION AND RUNNING-GEAR CONTROL SYS-
TEMS” on Page 217.
Before driving offTires
fCheck tread depth and tire pressure.
fCheck for damage and remove any foreign ob-
jects (e.g. stones) from the tread.
fReplace missing valve caps.
Rims
fReplace dented or damaged rims before
driving off road.
After driving off roadOff-road driving places a greater burden on the ve-
hicle than does normal driving on roads.
We recommend inspecting the vehicle after off-
road driving. Potential damage poses an accident
risk and impairs driving comfort. Damage on the
car is recognised in good time if the car is
checked.
Warning!
Car damage poses an accident risk for the
vehicle occupants and other road users.
fIn cases of doubt, have your vehicle checked
by your authorized Porsche dealer.
fExamine tires for signs of damage such as
cuts, tears, bulges or foreign objects stuck in
the tread. Replace a damaged tire if neces-
sary.
fHave any damage to your vehicle repaired by an authorized Porsche dealer without delay.

Maintenance, Car Care
243
Radiator fansThe radiator and radiator fans are in the front of
the car.
Warning!
Danger of injury. The fans can start running
as a function of temperature, even with the
engine switched off.
fExercise extreme caution when working in the area of the radiator fans.
Engine OilEngine oil consumption
It is normal for your engine to consume oil.
The rate of oil consumption depends on the quality
and viscosity of oil, the speed at which the engine
is operated, the climate, road conditions as well
as the amount of dilution and oxidation of the lubri-
cant.
If the vehicle is used for repeated short trips, and
consumes a normal amount of oil, the engine oil
measurement may not show any drop in the oil lev-
el at all, even after 600 miles (1000 km) or more.
This is because the oil is gradually becoming dilut-
ed with fuel or moisture, making it appear that the
oil level has not changed.
The diluting ingredients evaporate out when the
vehicle is driven at high speeds, as on an express-
way, making it then appear that oil is excessively
consumed after driving at high speeds.
If the conditions you drive your vehicle in are
dusty, humid, or hot, the frequency of the oil
change intervals should be greater.If the vehicle is driven at a high rate of speed, cli-
matic conditions are warm, and the load is high,
the oil should be checked more frequently, as driv-
ing conditions will determine the rate of oil con-
sumption.
– The engine in your vehicle depends on oil to lu-
bricate and cool all of its moving parts. There-
fore, the engine oil should be checked regular-
ly and kept at the required level.
– Make it a habit to have the engine oil level
checked with every fuel filling.
– The oil pressure warning light is not an oil level
indicator.
The oil pressure warning light indicates serious
engine damage may be occuring when lit, if en-
gine rpm is above idle speed.

Maintenance, Car Care
249
Coolant LevelfPlease observe the chapter “EXERCISE
EXTREME CAUTION WHEN WORKING ON YOUR
VEHICLE” on Page 242.
The coolant provides year-round protection from
corrosion and freezing down to -31°F (-35°C)
(Nordic countries -40°F (-40°C)).
fUse only anti-freeze authorized by Porsche.
fCheck the coolant level regularly.Checking coolant level/adding coolantThe expansion tank for the coolant is located un-
der the engine-compartment cover in the engine
compartment.
When the engine is cold and the car is level, the
coolant level must lie between the minimum and
maximum marks.Checking when engine is cold
1. Remove cover.2. Open cap of the expansion tank carefully and
allow any overpressure to escape.
Then unscrew cap completely.
3. Read the coolant level.
4. Top up with coolant if necessary.
Do not exceed the max. mark.
Only add a mixture of anti-freeze and water in
equal parts.
Antifreeze in coolant:
50% provides anti-freeze protection down to
-31°F (-35°C).
5. Screw the cap closed firmly and put on the
cover.
f f f

250
Maintenance, Car Care Checking the coolant level when a warning
messages is shown on the multi-purpose
display of the instrument panel
Warning!
Danger of serious personal injury from scald-
ing. Coolant is hazardous to your health, and
may be fatal if swallowed.
fDo not open the cap of the expansion tank
while the engine is hot.
fAllow the engine to cool down before opening
the cap and protect your hands, arms and face
from any possible escape of hot coolant.
fKeep coolant out of children's reach.
fAlso, keep coolant away from your pets.They
can be attracted to it should there be a spill, or
to used coolant left in an open container. Cool-ant can be deadly to pets if consumed.1. Remove cover.
2. If the engine is hot, cover the the expansion
tank cap with a cloth.
Open cap carefully and allow any overpressure
to escape.
Then unscrew cap completely.
3. Read the coolant level.
Top up with coolant if necessary.
Only add a mixture of anti-freeze and water in
equal parts.
Antifreeze in coolant:
50% provides anti-freeze protection down to
-31°F (-35°C).
Do not exceed the max. mark.
Note on operation
fIf the coolant level exceeds the max. mark
when the engine is hot, check the coolant level
again when the engine is cold.
4. Screw the cap closed firmly and put on the
cover.
5. Have the cooling system checked by an autho-
rized Porsche dealer.Maintenance note
If in an emergency pure water has been added, the
mixture ratio must be corrected at an authorized
Porsche dealer.
Marked loss of coolant indicates leakage in the
cooling system.
The cause should be remedied at an authoized
Porsche dealer immediately.

258
Maintenance, Car Care
Fuel EconomyFuel economy will vary depending on where,
when and how you drive, optional equipment
installed, and the general condition of your
car.
A car tuned to specifications and correctly
maintained, will help you to achieve optimal
fuel economy.
fHave your vehicle tuned to specifications. Air
cleaner should be dirt free to allow proper en-
gine “breathing“.
Battery should be fully charged.
Wheels should be properly aligned.
Tires should be inflated at correct pressure.
fAlways monitor your fuel consumption.
fDrive smoothly, avoid abrupt changes in speed
as much as possible.
fAvoid jack rabbit starts and sudden stops.
fDo not drive longer than necessary in the lower
gears. Shifting into a higher gear early without
lugging the engine will help save fuel.
fProlonged “warm up“ idling wastes gas. Start
the vehicle just before you are ready to drive.
Accelerate slowly and smoothly.fSwitch off the engine if stationary for longer
periods.
fAny additional weight carried in the vehicle re-
duces fuel economy. Always keep cargo to a
minimum and remove all unnecessary items.
fOrganize your trips to take in several errands
in one trip.
fAll electrical accessories contribute to in-
creased fuel consumption.
fOnly switch on the air conditioning when neces-
sary.
fDo not drive with the Roof Transport System
mounted unless you need it.
The EPA estimated m.p.g. is to be used for
comparison purposes, actual mileage may
be different from the estimated m.p.g., de-
pending on your driving speed, weather con-
ditions and trip length. Your actual highway
mileage will probably be less than the esti-
mated m.p.g.
fPlease observe all local and national speed lim-
its.
Operating Your Porsche in other
CountriesGovernment regulations in the United States and
Canada require that automobiles meet specific
emission regulations and safety standards. There-
fore, cars built for the U.S. and Canada differ from
vehicles sold in other countries.
If you plan to take your Porsche outside the conti-
nental limits of the United States or Canada, there
is the possibility that
– unleaded fuel may not be available;
– unleaded fuel may have a considerably lower
octane rating. Excessive engine knock and se-
rious damage to both engine and catalytic con-
verters could result;
– service may be inadequate due to lack of prop-
er service facilities, tools or diagnostic equip-
ment;
– replacement parts may not be available or very
difficult to get.
Porsche cannot be responsible for the me-
chanical damage that could result because
of inadequate fuel, service or parts availabil-
ity.
If you purchased your Porsche abroad and want to
bring it back home, be sure to find out about ship-
ping and forwarding requirements, as well as cur-
rent import and customs regulations.