202
Shifting Gear, Traction Systems
M - Manual selection mode (in the road
driving program)The functions of selector lever positions Dand M
differ in the on-road program, High Range, and in
the off-road program, Low Range.
The currently selected gear is retained if you
change from D to M.
If you change from M to D, the gear-changing map
suitable for your current driving style is selected
and the appropriate gear is selected.
Warning!
The kickdown function is not active in manual
selection mode “M“.
The kickdown function cannot be used to
downshift in manual selection mode “M“.
fTherefore shift down manually when accelerat-ing (e.g. to overtake).
Shifting up
fPress upper part (+) of a rocker switch Aor
fPush selector lever B forward in the M gate.
Shifting down
fPress lower part (–) of a rocker switch Aor
fPush selector lever B back in the M gate.
Depending on driving speed and engine speed,
you can shift up or down at any time. Gear chang-
es which would exceed the upper or lower engine-
speed limit are not executed by the control unit.You can change down two gears by quickly press-
ing rocker switches A or selector lever B twice.
If PSM is active and the engine-speed limit is
reached, an automatic upward shift is performed
or, just before idling speed is reached, a down-
ward shift is performed.
fSelect an appropriately low gear on upward
and downward slopes.
This will ensure optimum use of engine power
and engine braking.
If manual mode fails, the control electronics
switch to automatic mode.
In this event, the instrument panel will display se-
lector lever position D.
fTo remedy the fault, please consult an autho-
rized Porsche dealer.
Shifting Gear, Traction Systems
203
M - Manual selection mode (in the off-
road driving program)The functions of selector lever positions Dand M
differ in the on-road program, High Range, and in
the off-road program, Low Range.
The currently selected gear is retained if you
change from D to M.
If you change from M to D, the gear-changing map
suitable for your current driving style is selected
and the appropriate gear is selected.
Warning!
The kickdown function is not active in manual
selection mode “M“.
The kickdown function cannot be used to
downshift in manual selection mode “M“.
fTherefore shift down manually when accelerat-ing (e.g. to overtake).
Tip on driving
The kickdown function is not active in selector le-
ver position M.
Unlike in the road driving program, an automatic
upshift is not performed when the engine-speed
limit is reached.
Shifting up
fPress upper part (+) of a rocker switch Aor
fPush selector lever B forward in the M gate.Shifting down
fPress lower part (–) of a rocker switch Aor
fPush selector lever B back in the M gate.
Depending on driving speed and engine speed,
you can shift up or down at any time. Gear chang-
es which would exceed the upper or lower engine-
speed limit are not executed by the control unit.
You can change down two gears by quickly press-
ing rocker switches A or selector lever B twice.
The gear is changed down automatically just be-
fore idle speed is reached.
fSelect an appropriately low gear on upward
and downward slopes.
This will ensure optimum use of engine power
and engine braking.
If manual mode fails, the control electronics
switch to automatic mode. In this event, the instru-
ment panel will display selector lever position D.
fHave the fault eliminated at your authorized
Porsche dealer.
StoppingfFor a brief stop (e.g. at a traffic light), leave the
selector lever in drive position and hold the ve-
hicle with the brake pedal.
fDo not hold the car on a slope using the accel-
erator. Use the brake pedal or the parking
brake instead.
fBefore leaving the vehicle, always apply the
handbrake and move the selector lever to
positionP.
Tip on driving
In selector lever positions D and M, the Hillholder
prevents the car from rolling backward when it has
been stopped on an upward slope with the engine
running.
fPlease observe the chapter “HILLHOLDER” on
Page 218.
Shifting Gear, Traction Systems
207
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:
– 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 programfReduce speed to below 9 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 diode B.
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 211.
Low Range indicator light
208
Shifting Gear, Traction Systems
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 (lon-
gitudinal lock) is indicated on the multi-purpose
display of the instrument panel and by the illu-
mination of the two light-emitting diodes Band
C.
The center differential lock is changed over to
fully engaged state by the automatic control
system.
A- Rocker switch
B- Low Range is engaged
C- Centre 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 vehicle to continue moving neverthe-
less.
Shifting Gear, Traction Systems
209
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,
Cand D.
The center and rear differential locks are
changed over to fully engaged state by the
automatic 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.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.
210
Shifting Gear, Traction Systems 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
delaer and have the fault remedied.
fPlease observe the chapter “WARNING LIGHTS
AND WARNING MESSAGES” on Page 106.
Changing from off-road driving program
to on-road driving programfReduce 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 211.
Indicator light and warnings
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