2005 PORSCHE CAYENNE S torque

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

220
Shifting Gear, Traction Systems
Porsche Stability Management (PSM)PSM is an active control system for stabilisation of
the vehicle during extreme driving maneuvres. It
operates together with the Porsche Traction
Management (PTM) system.
PSM makes use of both the ABD and TCS sys-
tems, as well as the known functions of the anti-
lock brake system (ABS) and engine drag torque
control system (MSR).
Safety notes!
In spite of the advantages of PSM, it is still the driv-
er’s responsibility to adapt his driving style and
maneuvres in line with road and weather condi-
tions, as well as the traffic situation.
The increased safety that is provided should not in-
duce you to take greater risks with your safety.
The limits set by the physics of driving cannot be
overcome, even with PSM.
Risks of accident due to inappropriate speed
cannot be reduced by PSM.Advantages of PSM
– Best possible traction and lane-holding ability
in all driving situations – even on road surfaces
with varying friction.
– The system compensates for undesired vehi-
cle reactions (Ferraria effect) when the driver
releases the accelerator pedal or brakes on
bends. This compensation functions up to the
maximum lateral acceleration.
– PSM actively stabilises the vehicle in the event
of under and oversteering during dynamic
driving maneuvres (e.g. rapid steering move-
ments, during lane changes or on alternating
bends).
– Improved braking stability on bends and on dif-
ferent or varying road surfaces.Readiness for operation
PSM is switched on automatically every time you
start the engine.
Function
Sensors at the wheels, brakes, steering system
and engine continuously measure:
–Driving speed
– Direction of travel
– Lateral acceleration
– Longitudinal acceleration
– Rate of turn about the vertical axis
PSM uses these values to determine the direction
of travel desired by the driver.
PSM intervenes and corrects the course if the ac-
tual direction of motion deviates from the desired
course (steering-wheel position):
It brakes individual wheels as needed. If neces-
sary, PSM additionally influences the engine power
or the gear-changing characteristic of the Tiptron-
ic in order to stabilise the vehicle.

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.

254
Maintenance, Car Care
Air CleanerfPlease observe the chapter “EXERCISE
EXTREME CAUTION WHEN WORKING ON YOUR
VEHICLE” on Page 242.
Regular replacement of the filter element is part of
servicing.
fIn dusty conditions, clean the filter element
more frequently and replace if necessary.Particle FilterThe fresh air passing through the particle filter into
the passenger compartment is virtually free of
dust and pollen.
fIf the outside air is polluted by exhaust fumes,
press the circulating-air button.
A dirty filter can be the cause of reduced air
throughput.
fHave filter replaced by your authorized
Porsche dealer.
Regular replacement of the filter is part of servic-
ing.
Automatic Transmission Fluid The torque converter and the transmission are lu-
bricated with Automatic Transmission Fluid (ATF).
fPlease observe the chapter “CAPACITIES” on
Page 362.
Do not tow the car or run the engine without ATF
in the transmission. The automatic transmission
may be damaged by even a tiny speck of dirt, only
a clean funnel or spout must be used when adding
AT F.
The ATF and transmission oil has to be checked
and changed at the intervals listed in your Mainte-
nance Schedule.
We recommend that you have the ATF and trans-
mission oil changed at your Porsche dealer, who
has the required lubricants and the necessary fill-
ing equipment.
If you suspect an oil leak in the transmission, have
your authorized Porsche dealer check it out imme-
diately.
Manual Transmission OilThe transmission oil has to be checked and
changed at the intervals listed in your Maintenance
Schedule.
fPlease observe the chapter “CAPACITIES” on
Page 362.
We recommend that you have the transmission oil
changed at your Porsche dealer, who has the re-
quired lubricants and the necessary filling equip-
ment.
If you suspect an oil leak in the transmission, have
your authorized Porsche dealer check it out imme-
diately.

286
Practical Tips, Minor Repairs
Removing and storing tiresfAfter changing, adjust tire pressure and torque
wheel bolts diagonally.
Please observe the chapter “CHANGING
WHEELS” on Page 294.
Tires must always remain on the same side of
the vehicle.
When wheels are removed, the direction of rota-
tion and position of each wheel should be marked.
Example
FR (front right), FL, RR and RL.
Wheels must always be fitted in accordance with
their marking.
The perception that tire durability and perfor-
mance are not affected by storage and age is
unfounded.
Chemical additives, which make the rubber elas-
tic, lose their effectiveness over the course of
time and the rubber becomes brittle and cracks.
Therefore, the tires, especially the spare tire,
should be inspected from time to time.Note
Under no circumstances should tires older than
6 years be used on your Porsche.
The age of the tire can be obtained from the “DOT“
code number. If, for example, the last three num-
bers read 1204, then the tire was produced in the
12th week of 2004.
fStore tires in a cool and dry place.
fRotate periodically to avoid flat spots.
Snow tiresThe installation of Porsche approved winter tires is
recommended.
Use Porsche approved winter tires for grip on
snow and ice. For optimum performance, stud-
ding can be considered.
Check with your local Motor Vehicle Bureau for
possible restrictions.
Danger!
Risk of loss of control and damage to the
vehicle as well as serious personal injury or
death.
The standard tires profile and rubber mixture
are optimized for wet and dry driving condi-
tions, and may not prove favorable for snow
conditions.
fInstall winter tires before driving in such condi-tions.
Before mounting winter tires, consult with your
Porsche dealer. He has the technical information
necessary to advise you on wheel and tire compat-
ibility.
S n o w t i re s s h o u l d h a v e t h e s a m e l o a d c a p a c i t y a s
original equipment tires and should be mounted on
all four wheels.
Winter tires with studs should be run at moderate
speeds when new in order to give the studs time
to settle.

Practical Tips, Minor Repairs
293
CompressorOn vehicles without level-control systems, there is
an additional compressor with pressure tester
under the loadspace floor.
On vehicles with level control, you can use the
compressor of the level-control system to fill the
tires.
The filler hose required for this purpose can be
found under the left rear seat.
fPlease observe the chapter “FOLDING REAR
SEATS FORWARD” on Page 37.
fPlease observe the chapter “INFLATING TIRES
ON VEHICLES WITHOUT AIR SUSPENSION” on
Page 303.
Wheel BoltsfAlways clean the wheel bolts before installing.
Maintenance note
fWheel bolts must not be greased.
fReplace damaged wheel bolts.
Only use the original Porsche wheel bolts spe-
cially designed for this vehicle type.Tightening torque
Tightening torque of the wheel bolts 118 ftlb.
(160 Nm).
Security wheel boltsThe adapter (wrench socket) for the security
wheel bolts is located in the tool box.
To loosen or tighten the wheel bolt with anti-theft
protection, the adapter must be used between the
wheel bolt and the wheel bolt wrench.
fWhen positioning the wrench socket, ensure
that it engages fully in the teeth of the wheel
bolt.
Note on operation
If the wheels have to be removed at the workshop,
please do not forget to hand over the socket for
the security wheel bolts along with the car key.

Practical Tips, Minor Repairs
301
Wheel change1. Remove the top wheel bolt with the wheel bolt
wrench from the tool kit.
Screwing in assembly aid 2. Remove assembly aid from the tool kit and
screw in instead of the wheel bolt.
3. Remove the remaining wheel bolts.
Please observe the chapter “WHEEL BOLTS”
on Page 293.
4. Change wheel.5. Insert wheel bolts and tighten by hand.
Remove assembly aid and screw in remaining
wheel bolt.
Initially tighten bolts in diagonally opposite
sequence so that the wheel is centered.
6. Inflate the tire.
Please observe the chapter “TIRE PRES-
SURES, COLD” on Page 361.
In vehicles with tire pressure monitoring sys-
tem:
Please observe the chapter “TIRE PRESSURE
MENU” on Page 89.
7. Lower car and remove jack.
8. Tighten wheel bolts in diagonally opposite
sequence.
Maintenance note
fImmediately after changing a wheel, use
a torque wrench to check the prescribed
tightening torque of the wheel bolts
(118 ftlb./160 Nm).

Practical Tips, Minor Repairs
323
Removing and installing battery
Danger!
Danger of explosion and injury and risk of
short circuit and damage to the alternator
and electronic control units.
fHave the battery removed and installed only by
a qualified professional.
fDo not disconnect battery while the engine is
running.
fDisconnect and connect the battery only with
the greatest care. Danger of short circuit and
explosion.
fDo not tilt the battery when removing it.Risk of caustic burns from escaping acid.
The battery is located in the battery box under the
left front seat.
If the battery is completely discharged, the vehicle
must be provided with external power at the jump-
lead starting points so that you can move the seat.
fPlease observe the chapter “EMERGENCY
STARTING WITH JUMPER CABLES” on
Page 331.Maintenance note
The seat mounting bolts must be replaced each
time they are loosened.
The bolts are micro-encapuslated and keep dust
and water out.
If this is not observed, it might not be possible to
attain the prescribed tightening torque of 37 ftlb
(50 Nm).
Removing battery
1. Switch off all electrical loads and withdraw the
ignition key.
2. Move the left front seat all the way back and
up.
Move the backrest fully upright.
3. Unclip front seat trim A.
f f f