Shifting Gear, Traction Systems
215
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.
216
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 340.
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
217
ABS
(Anti-lock Brake System)
Caution!
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
221
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 211.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 necessa-
ry.
fHave any damage to your vehicle repaired by an authorized Porsche dealer without delay.
Recommended procedure
fDeactivate Low Range.
fClean headlights and tail lights and check them
for signs of damage.
fClean the front and rear licence 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.
224
Shifting Gear, Traction Systems
Water crossingfPlease observe the chapter “GROUND CLEA-
RANCE” on Page 355.
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
depthA, water speed and the condition of the
surface beneath it.
The water must not be deeper than 22 in. or
55.5 cm.
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.
230
Shifting Gear, Traction Systems Lowering the vehicle
1st actuation: Low level
2nd actuation: Loading level
Warning messageVarious messages are indicated on the multi-pur-
pose display of the instrument panel if there is a
system fault or if the compressor switches off due
to overload.fPlease observe the chapter “WARNING LIGHTS
AND WARNING MESSAGES” on Page 106.
fAdapt your driving behavior to the changed
conditions.
fConsult an authorized Porsche dealer in order
to remedy a system fault.
fIf the overload-protection function causes the
compressor to switch off, wait for a time until
it has cooled down. The system will function
again as soon as it has cooled sufficiently.
The warning message appears when the control
system is switched off and when the collapsible
spare wheel is being filled. This does not indicate
a fault.
The warning message will go out once these pro-
cedures have been completed.
Raising vehicle with the jackWhenever it is necessary to jack up the vehicle:
fManually set normal level and then switch off
level control.
Switching off level control
1. Switch ignition on.
2. Push rocker switch forward for 5 to
10 seconds.
A message is shown on the multi-purpose
display of the instrument panel.
The vehicle can now be raised.
Switching level control back on
1. Switch ignition on.
2. Push rocker switch forward for 5 to
10 seconds or
3. Drive forward with the vehicle.
Level control switches on automatically.Transporting the vehicles on car trains,
ferries and car transportersfTie the vehicle down only at its wheels.
236
Maintenance, Car Care
Engine Oil LevelfPlease observe the chapter “EXERCISE
EXTREME CAUTION WHEN WORKING ON YOUR
VEHICLE” on Page 234.
fPlease observe the chapter “WARNING LIGHTS
AND WARNING MESSAGES” on Page 106.
fCheck the oil level regularly. It is best to do this
when refuelling and before extended journeys.
Warning!
Engine oil is hazardous to your health and
may be fatal if swallowed.
fKeep engine oil out of children's reach.
Used engine oil contains chemicals that have
caused cancer in laboratory animals.
fAlways protect your skin by washing thorough-ly with soap and water.If the oil level is too low, this is indicated by the oil-
level warning light lighting up on the multi-purpose
display.
fCheck the oil level using the oil dipstick as
soon as possible and add engine oil if neces-
sary.
Note on operation
fIf the engine compartment lid is opened and oil
is not added, the warning message appears
again after approximately 62 miles (100 km).
Checking the oil level
Warning!
Danger of injury. The radiator fans can start
running as a function of temperature, even
with the engine switched off.
Risk of burning from hot parts in engine com-
partment.
fExercise extreme caution when working on the engine compartment.
Conditions for measuring the oil level
correctly
– Vehicle must be level.
– Engine must be switched off and at operating
temperature.
– Before the oil-level measurement, allow the en-
gine oil to flow back into the oil pan for around
3 minutes.
Oil-level warning
Maintenance, Car Care
243
Changing the brake fluidBrake fluid absorbs moisture from the air over
time. This accumulation of water lowers the boil-
ing point and, under certain operating conditions,
can affect the braking action.
fTherefore, have the brake fluid changed in ac-
cordance with the change intervals stated in
the booklet “Maintenance”.
The warning light in the instrument panel and the
warning message on the multi-purpose display of
the instrument panel
– indicate the brake level fluid is too low or,
– in conjunction with large pedal travel could
indicate a braking-circuit failure.
Note on operation
fStop immediately in a suitable place.
fDo not continue driving.
Please have the fault remedied at your nearest
authorized Porsche dealer.
Washer FluidThe washer-fluid reservoir for windshield, rear win-
dow and headlights is located in the engine com-
partment.Warning message on the multi-purpose
displayA message is shown on the multi-purpose display
of the instrument panel if the washer-fluid level is
too low.
In this case, the residual quantity is only around
0.85 quarts or 0.8 liters.
fAdd washer fluid at the next opportunity.
Topping off washer fluidThe capacity is approx. 7.9 quarts or 7.5 liters.
Clean water is generally not enough to clean the
windows and headlights.
It is advantageous to add a winter cleaner giving
antifreeze protection or a suitable summer clean-
er, depending on the season. Follow the instruc-
tions for the mixture ratio.
fUse only cleaner authorized by Porsche.
1. Please note all the information on the refill
container of the cleaning agent.
2. Open cap of the washer-fluid reservoir.
3. Top up washer fluid and close cap properly.
fDo not use engine coolant anti-freeze or any
other solution that can damage the car’s paint,
in the washer reservoir.
Brake fluid warning light
USA
Brake fluid warning light
Canada