Shifting Gear, Traction Systems
231
Vehicles with Tiptronic S
fReduce speed to below 9.3 mph (15 km / h) or
stop vehicle.
fMove selector lever to position N.
fPush rocker switch A forward until activation of
the off-road driving program is indicated on the
multi-purpose display of the instrument panel
and by illumination of light-emitting diodeB.
The Low Range indicator light on the instru-
ment panel and light-emitting diode B beside
the rocker switch flash several times during
the shifting process.
Low Range is now engaged.
Danger!
Serious risk of injury or death. Risk of
accident due to uncontrolled vehicle
movement. The selector lever is blocked
during the shifting procedure. Shifting when
driving uphill can cause the vehicle to stand
still or even roll backwards, if the shifting
procedure has not yet been completed.
When driving downhill, the vehicle can accel-
erate unintentionally while shifting.
fIncreased brake readiness is required.
fPlease observe the chapter “POWER-TRANS-
MISSION AND RUNNING-GEAR CONTROL SYS-
TEMS” on Page 235.
A- Rocker switch
B- Low Range is engaged
C- Center differential lock is fully engagedFully engaging the center differential lock
in Low RangeTip on driving
When the center differential lock is fully engaged,
there is no longer any speed difference between
the front and rear axles. If, for example, both
wheels at the front axle lose traction on an icy
road or soft surface, the rigidly linked drive wheels
will permit the vehicle to continue moving never-
theless.fPush rocker switch A forwards in stages until
engagement of the center differential lock is in-
dicated on the multi-purpose display of the in-
strument panel and by the illumination of the
two light-emitting diodes B and C.
The center differential lock is changed over to
fully engaged state by the automatic control
system.
232
Shifting Gear, Traction Systems
A- Rocker switch
B-Low Range is engaged
C- Center differential lock is fully engaged
D- Rear differential lock is fully engagedFully engaging the rear differential lock in
Low RangeTip on driving
When the rear differential lock is fully engaged,
there is no longer any speed difference between
the two rear wheels. If, for example, one drive
wheel at the rear axle loses traction on an icy road
or soft surface, the stiff through-drive function will
permit the car to continue moving nevertheless.fPush rocker switch A forwards in stages until
engagement of the rear differential lock (trans-
verse lock) is indicated on the multi-purpose
display of the instrument panel and by the
illumination of the three light-emitting diodes B,
C and D.
The center and rear differential locks are
changed over to fully engaged state by the au-
tomatic control system.
Note on operation
The rear differential lock can only be engaged
while the engine is running.
Hydraulically disengageable anti-roll barsThe front and rear anti-roll bars can be disengaged
to improve traction and comfort when driving off
road. This feature increases the wheel articulation.
Condition for disengaging the anti-roll bars
– Low Range is engaged.
Note
The anti-roll bars cannot be engaged if the wheel
articulation or lateral acceleration is too great.
Shifting Gear, Traction Systems
233
Disengaging
fPress button E.
Disengagement of the anti-roll bars is indicated
on the multi-purpose display of the instrument
panel and by illumination of light-emitting diode
F.
The light-emitting diode on the button flashes
several times during the disengagement
process.
The anti-roll bars are disengaged.
Note on operation
The anti-roll bars cannot be disengaged manually
at speeds above 25 mph (40 km/h).
Engaging
fPress button E.
Light-emitting diode F on the button flashes
several times during the engagement
process and then goes out.
The anti-roll bars are engaged.Note on operation
The anti-roll bars are engaged automatically when
a speed of 30 mph (50 km/h) is exceeded or
when the lateral acceleration value is high.
Notes
Engagement of the anti-roll bars is audible.
At temperatures below –4°F (–20°C), the anti-roll
bars take somewhat longer to engage.Indication of a fault by:
– Continuous illumination of the light-emitting
diode in the button
– Illumination of the warning light on the
instrument panel
– A message on the multi-purpose display of the
instrument panel
fAdapt your driving behavior to the changed
conditions.
Drive slowly to the nearest authorized Porsche
dealer and have the fault remedied.
fPlease observe the chapter “WARNING LIGHTS
AND WARNING MESSAGES” on Page 124.
Indicator light and warnings
234
Shifting Gear, Traction Systems
Changing from off-road driving program
to on-road driving programVehicles with manual transmission
fStop the vehicle.
fApply the brake.
fPut the gearshift lever in neutral.
fPull rocker switch A back in stages until light-
emitting diodes B, C and if necessary, D are
out.
The Low Range indicator light on the instru-
ment panel and light-emitting diode B beside
the rocker switch flash several times during
the shifting process.
High Range is active.Vehicles with Tiptronic S
fReduce speed to below 19 mph (30 km / h) or
stop vehicle.
fMove selector lever to position N.
fPull rocker switch A back in stages until light-
emitting diodes B, C and if necessary, D are
out.
The Low Range indicator light on the instru-
ment panel and light-emitting diode B beside
the rocker switch flash several times during
the shifting process.
High Range is active.
Danger!
Serious risk of injury or death. Risk of
accident due to uncontrolled vehicle
movement. The selector lever is blocked
during the shifting procedure. Shifting when
driving uphill can cause the vehicle to stand
still or even roll backwards, if the shifting
procedure has not yet been completed.
When driving downhill, the vehicle can accel-
erate unintentionally while shifting.
fIncreased brake readiness is required.
fPlease observe the chapter “POWER-TRANS-
MISSION AND RUNNING-GEAR CONTROL SYS-
TEMS” on Page 235.
Shifting Gear, Traction Systems
239
The events below inform the driver of PSM control
operations and warn him to adapt his driving style
to the road conditions:
– The multi-functional information light in the in-
strument 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 cor-
ner, engine power is reduced and the rear
wheel on the inside of the corner is braked if
necessary.
–Vehicle oversteers:
If the rear of the vehicle swings out on a cor-
ner, the front wheel on the outside of the cor-
ner 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 unders-
teer 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.
240
Shifting Gear, Traction Systems
Switching off PSMfPress PSM OFF button A.
PSM is switched off after a short delay.
The light-emitting diode in the button lights up.
When the PSM is switched off, the multifunc-
tional PSM light on the instrument panel is lit
and a message appears in the multi-purpose
display of the instrument panel.
During braking, the vehicle is stabilised even
when PSM is switched off.
One-sided spinning of the wheels is prevented,
even with PSM switched off.PSM should always be switched on during
“normal” driving.
H o w e v e r, i t c a n b e o f a d v a n t a g e t o s w i t c h o f f P S M
temporarily in exceptional situations:
– On a loose surface or in deep snow
– When “rocking the vehicle free”
– When using snow chains.
Vehicles with Tiptronic: When the PSM is
switched off the slip monitoring function is also de-
activated.
– The multifunctional light on the instrument
panel lights up for a lamp check when the
ignition is switched on.
– The light indicates a control operation,
including when PSM is switched off (brake
control in the event of one-sided wheel spin).
– Faults are displayed by the light in conjunction
with the multi-purpose display of the instru-
ment panel.
PSM is out of order.
Consult your authorized Porsche dealer.Collapsible spare wheel
fNever switch the PSM off when driving with a
collapsible spare wheel.
To w i n g
fPlease observe the chapter “TOWING” on
Page 374.
Tip on driving
When PSM is switched off, wheel-specific brake in-
terventions and the traction control system (TCS)
are also inactive.
The automatic brake differential (ABD) remains on.
Switching PSM back onfPress PSM OFF button A.
PSM is switched on after a short delay.
Multifunctional PSM light
Shifting Gear, Traction Systems
241
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
Shifting Gear, Traction Systems
247
Recommended procedure
fDeactivate Low Range.
fClean headlights and tail lights and check them
for signs of damage.
fClean the front and rear lincense plates.
fClean the tire tread with a jet of water and re-
move any foreign objects.
fClean wheels, wheel housings and the under-
body with a jet of water.
fCheck whether the car has picked up plant
parts or branches.
These materials increase the risk of fire and
can damage fuel lines, brake hoses, boots of
the axle joints and drive shafts.
fAfter off-road driving, always check the entire
floor assembly, tires, body structure, steering
system, running gear and exhaust system for
signs of damage.fAfter driving for an extended period through
mud, sand, water or substances with a similar
soiling effect, check the brake discs, brake
pads, wheels and axle joints and have them
cleaned.
fIf you experience severe vibrations after
driving off road, check the wheels for foreign
substances.
These substances can produce an imbalance
which might be responsible for the vibrations.
Removing these deposits may remedy the
problem.