Porsche Cayenne Turbo Driver Manual page 187

Automatic brake differential (ABD)
The ABD system controls the front and rear axles
separately. If one wheel of an axle starts to spin,
it is braked so that the other wheel on the same
axle can be driven.
ABD recognises different driving states, and it
features control strategies adapted to these
states. In situations in which little propulsive power
is required, such as when the vehicle moves off on
a level gravel surface, traction control already
becomes active at low engine speeds. If a large
amount of propulsive power is required, such as
when moving off on an uphill slope or for rapid
acceleration, the ABD system is adapted accord-
ingly.
A special off-road driving programme is used in
Low Range mode.
Traction control system (TCS)
The traction control system prevents the wheels
from spinning by adjusting the engine power,
thereby ensuring good lane-holding ability and
stable handling.
Porsche Stability Management (PSM)
PSM is an active control system for stabilisation of
the vehicle during extreme driving manoeuvres. It
is networked with the Porsche Traction Manage-
ment (PTM) system.
PSM makes use of both the ABD and TCS
systems, as well as the known functions of the
anti-lock brake system (ABS) and engine drag
torque control system (MSR).
Safety notes!
In spite of the advantages of PSM, it is still the
driver's responsibility to adapt his driving style and
manoeuvres in line with road and weather condi-
tions, as well as the traffic situation.
The increased safety that is provided should not
induce you to take greater risks with your safety.
The limits set by the physics of driving cannot be
overcome, even with PSM.
Risks of accident due to inappropriate speed
cannot be reduced by PSM.
Advantages of PSM
– Best possible traction and lane-holding ability
in all driving situations – even on road surfaces
with varying friction.
– The system compensates for undesired
vehicle reactions (Ferraria effect) when the
driver releases the accelerator pedal or brakes
on bends. This compensation functions up to
the maximum lateral acceleration.
– PSM actively stabilises the vehicle as required
during dynamic driving manoeuvres (e.g. rapid
steering movements, during lane changes or
on alternating bends).
– Improved braking stability on bends and on
different or varying road surfaces.
– Improved brake functioning and reduced
stopping distance in the event of emergency
braking.
Driving and Driving Safety
187