engine PORSCHE CAYNNE TURBO 2006 1.G Repair Manual

Shifting Gear, Traction Systems
233
ABS
(Anti-lock Brake System)
Warning!
In spite of the advantages of ABS, 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 ABS.
Risks of accident due to inappropriate speed can-
not be reduced by ABS.
ABS ensures
–Full steering control
The vehicle remains steerable
–Good driving stability
No skidding due to locked wheels
–Optimum braking distance
Shorter stopping distances in most cases
–Lock prevention
No flat spots on the tiresFunction
The decisive advantage of ABS is in the driving
stability and maneuvrability of the vehicle in
hazardous situations, even during heavy braking
while cornering.
ABS prevents locking of the wheels during full
braking, on almost all road surfaces, until shortly
before the vehicle stops.
The ABS begins to control the braking process as
soon as a wheel shows a tendency to lock.
This controlled braking process is comparable to
extremely rapid cadence braking.
The pulsating brake pedal and a “rattling noise”
warn the driver to adapt his driving speed to the
road conditions.Warning light
If the ABS warning lights light up in the instrument
panel and on the multi-purpose display of the in-
strument panel while the engine is running, the
ABS has switched off because of a fault.
In this event, the braking system will operate with-
out lock prevention,as in cars without ABS.
fAdapt your driving style to the changed brak-
ing behavior.
fThe ABS must be checked immediately at an
authorized Porsche dealer. This is necessary
in order to prevent the occurrence of further
faults whose effects cannot be defined.
The ABS control unit is adjusted for the approved
tire dimensions.
The use of tires with non-approved dimensions can
lead to different wheel speeds, causing the ABS to
switch off.
f f f

234
Shifting Gear, Traction Systems Off-road ABS
(ABS in Low Range program)
When Low Range is active, an ABS specially
matched to off-road driving is activated automati-
cally.
At speeds below 30 mph (50 km/h), the front
wheels can lock up in cycles during braking to
shorten the braking distance when the vehicle is
driven off-road (the wheels dig in to the surface).
If the driver needs to steer, this off-road driving
program is automatically switched off briefly to
maintain steerability.
HillholderIn selector lever positions D and M, the Hillholder
function makes it easier to move off from a stand-
still on an upward slope when the engine is
running. The driver does not have to apply the
brake.
The hillholder thus makes moving off on slopes
easier.
Danger!
Risk of accident.
The vehicle can roll backwards if the Hillhold-
er is switched off.
fAlways apply the footbrake on slopes.
Hillholder is not active:
– In selector lever positions N and R
– In the reduced driving program and
– If not all of the wheels are touching the ground
(on difficult terrain, for example).
Warning!
In spite of the advantages of the hillholder func-
tion, it is still the driver’s responsibility to adapt his
driving style and maneuvers in line with situational
conditions.
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 the hillholder function.
Driving at the limits should be avoided, e.g., on icy
slopes or on slippery surfaces. In this and similar
cases, the support of the hillholder function is not
ensured.

Shifting Gear, Traction Systems
235
Engine Braking Support
(Assistance when heading downhill)The Porsche Down-Hill Assistant is an assistance
system which helps the driver at slower downhill
driving up to approx. 12 mph (20 km/h), e.g., on
steep slopes or on wintry mountain roads.
As long as the accelerator pedal is not used when
traveling downhill, the Porsche Down-Hill Assistant
is active and brakes the vehicle.
The braking ability of the Engine Braking Support
is affected by slippery surfaces (e.g., on icy or
loose surfaces), like all brakes.
If road grip is lost on one or more wheels, the
system brakes the wheels which have good road
contact.
Warning!
Risk of accident. Reduced braking ability on
a slippery surface.
fAlways adjust your driving style to the driving situationConditions:
– The gas pedal must not be used when
travelling downhill.
– The speed must not
exceed 12 mph (20 km/h).
– The selector lever position D, M or R must be
engaged.
Tip on driving
The Porsche Down-Hill Assistant is active when
driving downhill either forwards or backwards.
Checks on test standsPower measurement
Power measurements on roller test stands are not
approved by Porsche.
Brake tests
Brake tests must be carried out only in High Range
and on plate-type test stands or roller test stands.
The following limit values must not be exceeded
on roller test stands:
– Testing speed 4.7 mph (7.5 km/h)
– Test duration 20 seconds
Parking brake test
Parking brake tests on the brake tester must be
performed only with the ignition switched off and
the selector lever in position N.Balancing wheels on the vehicle
During finish balancing of the wheels, the entire ve-
hicle must be lifted and the wheels must be free to
turn.
Dynamometer testing procedure Some U.S. states and Canadian provinces con-
duct emissions inspection/maintenance testing in-
volving the use of two-wheel dynamometer.
A two-wheeled dynamometer is a treadmill type
device upon which a single axle of the car, the driv-
ing axle of the vehicle, rotates to simulate vehicle
operation on the road while the vehicle remains
stationary.
Your Porsche Cayenne has a full-time four-wheel
drive system which cannot be disabled. Severe
d a m a g e t o t h e p o w e r t r a i n c a n re s u l t i f t e s t e d o n a
two-wheel dynamometer.
Warning!
To avoid severe powertrain damage and a
possible unexpected movement of the vehi-
cle.
fYour Porsche Cayenne vehicle must never be
tested on a two-wheel dynamometer.
fAdvise the emission station of this warning be-fore testing the vehicle.

236
Shifting Gear, Traction Systems
Off-Road DrivingfPlease read this chapter carefully before driv-
ing off road with your Porsche.
The information provided will familiarise you with
the special advantages of your vehicle, allowing
you to arrive at your destination safely every time.
We recommend practicing on less rugged terrain.
Vehicles with SportDesign package
Caution!
Risk of damage. On vehicles with
SportDesign package, front, rear, and side
member trim are painted and pulled down
lower. Off-road driving can seriously damage
these trim parts.
fWhen driving off-road, make sure these parts
are not damaged.
fMake sure there is sufficient clearance
between obstacles and the underside of the
vehicle.
fAvoid driving through water.
fDo not use side member trim as a running board.Maintenance note
Please bear in mind that off-road driving subjects
all vehicle components to considerably more wear
than normal use, making professional inspection
and maintenance after each use a vital precondi-
tion for functioning and safety.
Grains of sand, dirt particles and other abrasive
materials entering the brakes can cause exces-
sive wear or unpredictable braking action.
Rules for off-road drivingfEnsure vehicle is equipped with approved all-
terrain tires.
fPlease observe the chapter “GROUND CLEA-
RANCE” on Page 375.
fActivate Low Range.
fStow or fasten luggage and loads securely.
Please observe the chapter “LOADING INFOR-
MATION” on Page 207.
fIf unknown terrain is obscured from view, ex-
amine it on foot first and traverse it with ex-
treme caution.
This way, obstacles are easier to recognise
and damage to the vehicle is avoided.fAlways drive with the engine running.
Steering assistance is provided only with the
engine running.
fDrive slowly and uniformly.
fAlways make sure that the wheels touch the
ground.
fBefore driving through water, check the water
depth, the condition of the surface beneath it
and the speed of the water.
fLook out for obstacles such as boulders,
holes, tree stumps or ruts.
fAlways keep the sliding/lifting roof or
Panorama roof system and the side windows
closed while driving.
fDo not depart from marked routes or paths.
fRespect nature.
Always obey off-limits signs.

238
Shifting Gear, Traction Systems
Uphill driving
Danger!
Danger of serious personal injury or death
and risk of damage if the vehicle should
overturn.
fDo not turn around when driving uphill.
fIf it is not possible to climb a gradient, the car
must be backed down in reverse gear.
fDo not drive over embankments or slopes at
steep diagonal angles.
fIf the vehicle starts to tilt, immediately steer in
the direction of the tilt (line of slope).
fWhen driving uphill, never let the vehicle roll
backward when in idle or not in gear.
Exclusive use of the footbrake is too risky in such situations.Note on operation
fActivate Low Range before taking extreme up-
ward or downward gradients.
Tips on driving
fDo not perform manual gear changes when
driving, and try to avoid stopping.
fAvoid high engine speeds (max. 2,500 rpm).
Traction on uphill slopesNote on operation
fActivate Low Range and engage differential
locks if necessary.
Tips on driving
fWhen driving uphill, go easy on the accelerator
and make sure that wheels have sufficient trac-
tion (don't spin).
fAvoid high engine speeds (max. 2,500 rpm).
fDrive slowly.

Shifting Gear, Traction Systems
239
Driving downhill
Danger!
There is a danger of serious personal injury
or death and risk of damage if the vehicle
should overturn.
fDo not drive over embankments or slopes at
steep diagonal angles.
fDrive downhill slowly, with the wheels pointing
straight ahead.
fIf the vehicle starts to tilt, immediately steer in
the direction of the tilt (line of slope).
fWhen driving downhill, never let the vehicle roll
when in idle.
fUse engine braking effect.
If the engine braking effect is not adequate, gently apply the foot brake.Note on operation
fActivate Low Range. The off-road ABS is
switched on automatically.
Tips on driving
The same general principle as for uphill driving ap-
plies to downhill driving.
fDo not perform manual gear changes when
driving, and try to avoid stopping.
fAvoid high engine speeds (max. 2,500 rpm).
A special circuit in the off-road ABS permits con-
trolled brief lock-up of the front wheels so that they
can dig into the loose surface more effectively.
Locked wheels slip and can no longer be steered.
fWhen driving down steep hills on unpaved sur-
faces, brake carefully so that vehicle does not
start to slide.

240
Shifting Gear, Traction Systems
Water crossingfPlease observe the chapter “GROUND CLEA-
RANCE” on Page 375.
Danger!
Danger of drowning if water enters the vehi-
cle. Risk of damage to the engine and acces-
sories if water penetrates.
fBefore driving through water, check the water
depth A, water speed and the condition of the
surface beneath it.
The water must not be deeper than 20 in.
(50 cm). The water must not be deeper than
22 in. (55.5 cm) for vehicles with level control
and height adjustment.
fCheck the door sills and rubber seals before
starting to drive.
fDo not drive through deep or rapidly flowing
water.
Deep or rapidly flowing water, e.g. mountain
streams, can cause the car to deviate from the
intended path.
fAvoid a "bow wave" by driving at an appropriate
speed.
fNever open the doors when driving through wa-
ter.Soiling can impair the braking action.
fCheck and clean the brakes if they have been
soiled.
Danger of steering assistance failing during
a long journey in the water if the drive belt
slips.
fIf the steering assistance fails, more effort will
be required to steer.
Danger of damaging electrical systems
fAvoid driving through salt water.
Notes on operation
fActivate Low Range.
fSwitch the air conditioner off.
fSwitch the headlights off.

Shifting Gear, Traction Systems
241
Tips on driving
fAvoid high engine speeds (max. 2,500 rpm).
fDo not perform manual gear changes when
driving, and try to avoid stopping.
Moving off in the water can be difficult due to
the high resistance and the loose surface in-
volved.
fStart the water crossing at a shallow place at
walking speed.
fAfter checking the body of water, take the
shortest path through it.
fNever drive into the water at high speed. The
resulting “bow wave” could damage the engine
and its accessories.
fAdjust your driving style to the unfamiliar sur-
roundings.
fCross the body of water slowly and at a con-
stant speed.
fNever turn around when crossing a body of wa-
ter.
fIf it is not possible to cross the body of water,
the car must be backed out of it in reverse
gear.
The servo pump and alternator can fail if the car is
driven through water for an extended period.
fIf the servo pump fails, substantially more
force will have to be exerted in order to steer. Maintenance note
The car requires a special check after the water
crossing.
fRemove mud from the tire tread.
fBriefly apply the brakes in order to dry them af-
ter driving through the water.
ObstaclesfPlease observe the chapter “GROUND CLEA-
RANCE” on Page 375.
Note on operation
fActivate Low Range and engage differential
locks if necessary.
Tips on driving
fJust before reaching the obstacle, ease off the
accelerator slightly and use the car's momen-
tum to cross the obstacle. This will prevent the
car from jumping over the hump and landing on
the following downward slope at an excessive
speed.
fAvoid high engine speeds (max. 2,500 rpm).

242
Shifting Gear, Traction Systems
Crossing obstacles
Caution!
Risk of damage to the underbody and chas-
sis components if obstacles are traversed
improperly.
fAlways bear in mind the ground clearance of
your vehicle.
fSlowly drive over the middle of tree trunks,
boulders or other obstacles with one of the
front wheels.
fCross the obstacle with the rear wheel in the same way.
Note on operation
fActivate Low Range and engage differential
locks if necessary.Tips on driving
fHave your passenger direct you if necessary.
fAvoid high engine speeds (max. 2,500 rpm).
fDrive slowly.

Shifting Gear, Traction Systems
243
Driving on sandNote on operation
fActivate Low Range and engage differential
locks if necessary.
Tips on driving
Loose sand is an especially tricky surface for off-
road driving.
You can often become stuck in sand within
minutes if you do not drive correctly in such
situations.
fDrive at brisk pace and do not stop under any
circumstances. This will reduce the chance of
the car becoming bogged down.
fFollow existing tracks – provided that they
have not been covered by blown sand, are not
too deep and the car's ground clearance is
sufficient.
Please observe the chapter “GROUND CLEA-
RANCE” on Page 375.
fAvoid high engine speeds (may. 2,500 rpm).When driving on slopes with soft sand:
fUse the manual select mode M in addition to
the Low Range program.
If your vehicle becomes stuck nevertheless:
fDo not spin the wheels. Instead, use branches,
mats or similar items to provide adequate trac-
tion so that you can drive out of the critical ar-
ea.
Track rutsOther vehicles leave ruts in many off-road courses
or gravel roads.
fPlease observe the chapter “GROUND CLEA-
RANCE” on Page 375.
Caution!
Risk of damage to the vehicle floor when
driving through ruts that are too deep.
fAlways bear in mind the car's ground clear-
ance.
fDo not drive over ruts that are too deep.
Note on operation
fActivate Low Range and engage differential
locks if necessary.
Tips on driving
fIn cases of doubt, drive with one wheel on the
strip of grass between the ruts.
fAvoid high engine speeds (max. 2,500 rpm).
fDrive slowly.