198
Controls, Safety, Instruments
Towing a trailer
Warning!
Driving with a trailer
fAlways observe the permissible towing capac-
ity, vertical coupling load and rear-axle load.
Please observe the chapter “WEIGHTS” on
Page 363.
fWhen connected, the trailer must always be
horizontal behind the towing vehicle. If neces-
sary, use a trailer with an adjustable drawbar.
fWhen the vehicle is driven in the mountains, the
engine output decreases as altitude increases.
The maximum weights stated are the values at
sea level. The total permissable weight of the
car-trailer combination must therefore be re-
duced by 10% for each increment of 3,280 ft.
(1,000 meters) altitude. A fractional increment
counts as the full 3,280 ft. (1,000 meters).
Please take this into consideration when plan-
ning your route.Distributing the load
fDistribute the load in the trailer so that heavy
objects are as close to the axle as possible.
Always safeguard all objects against slipping
and tie them down securely.
fYou should make the best possible use of the
trailer coupling's rated vertical coupling load
when loading the trailer, but never exceed it.
Tire pressure
fSelect the vehicle tire pressure for full load
when towing a trailer.
fPlease observe the chapter “Tire pressure ta-
bles”.
fCheck the tire pressure of the trailer's wheels
according to the manufacturer's instructions.Door mirrors
fIf the width of the trailer obstructs your view of
the traffic behind the trailer, you must have ad-
ditional door mirrors fitted.
Headlights, lights
fAlways check the headlight adjustment before
driving with a trailer.
If necessary, correct with the headlight beam
adjustment function.
fCheck whether the plug of the trailer is
plugged into the towing vehicle and whether all
lights function.
202
Shifting Gear, Traction Systems
Manual transmission, clutch
Warning!
Risk of accident.
fDo not obstruct the pedal travel with floor mats or other objects.
Floor mats of the correct size and with the
appropriate fasteners are available from your
authorized Porsche dealer.The positions of the gears are shown on the shift
diagram on the gearshift lever.
fWhen shifting gears, always ensure that the
clutch pedal is fully depressed and the gear
has fully engaged.
fSelect reverse only when vehicle is stationary.
fSelect an appropriately low gear on upward
and downward slopes.
This will ensure optimum use of engine power
and engine braking.
When reverse gear is selected and the ignition is
on, the reversing lights are lit.
Permitted engine speedfYou should change into a higher gear before
the needle reaches the red mark on the
tachometer, or ease off the accelerator.
If the red zone is reached during acceleration, fuel
feed is interrupted.
Caution!
Risk of engine damage (overrevving) when
shifting down to a lower gear.
fTake care not to exceed the maximum permit-ted engine speed when down-shifting.
212
Shifting Gear, Traction Systems If the Low Range indicator light beside the rocker
switch flashes when you attempt to operate rock-
er switch, the conditions for a shift have not been
met:
Vehicles with manual transmission
– Vehicle is not stationary.
– Brake is not pressed.
– Gear-shift lever is not in neutral.
Vehicles with Tiptronic S
– Vehicle has exceeded or gone below the limit
speed.
– Selector lever is not in position N.
A-Rocker switch
B- Low Range is engagedChanging from on-road driving program
to off-road driving programVehicles with manual transmission
fStop the vehicle.
fApply the brake.
fPut the gearshift lever in neutral.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 lights in the instru-
ment panel and beside the rocker switch flash
several times during the shifting process.
Low Range is now engaged.
Caution!
Risk of engine damage (overrevving). In the
Low Range program, the gear-changing
points are shifted towards lower engine-
speed ranges.
fShift early to prevent overrevving the engine.
Tip on driving
When Low Range is active, the power
transmission and running-gear control systems
are automatically adapted to the requirements for
off-road driving.
Low Range indicator light
Shifting Gear, Traction Systems
215
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 108.
Indicator light and warnings
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.
222
Shifting Gear, Traction Systems
Switching off PSMfPress button A.
PSM is switched off after a short delay.
With PSM switched off, the PSM warning light
in the instrument panel and the information
light in the button are lit.
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.
When the PSM is switched off the slip monitoring
function of the Tiptronic is also deactivated.
Information light
– The light indicates a control operation, includ-
ing when PSM is switched off (brake control in
the event of one-sided wheel spin).
Warning light
– The warning light in the instrument panel lights
up in combination with the indicator light in the
button for a lamp check when the ignition is
switched on.
– Together with the information light in the
button, the warning light indicates that PSM is
switched off.
– A fault is indicated by the warning light in the
instrument panel and an indication on the multi-
purpose display of the instrument panel. PSM
is out of order.
Please have the fault remedied at an autho-
rized 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 350.
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 on PSMfPress button A.
PSM is switched on after a short delay.
Shifting Gear, Traction Systems
223
ABS
(Anti-lock Brake System)
Safety notes!
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.
The ABS must be checked immediately at an
authorized Porsche dealer in order to prevent
the occurrence of further faults the effects of
which 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
229
Recommended procedure
fDeactivate Low Range.
fClean headlights and tail lights and check them
for signs of damage.
fClean the front and rear lincence 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.