114
8
S A F E T Y
TRAJECTORY CONTROL SYSTEMS
Anti-skid regulation (ASR) and
electronic stability programme (ESP)
The anti-skid regulation (also known
as Traction Control) optimises trac-
tion to prevent skidding of the wheels,
by acting on the brakes of the driving
wheels and on the engine.
The electronic stability programme
acts on the brake of one or more
wheels and on the engine to keep
the vehicle on the trajectory required
by the driver.
Activation
These systems are activated auto-
matically each time the vehicle is
started.
They come into operation in the event
of a grip or trajectory problem.
T h i s i s i n d i c a t e d b y fl a s h i n g
of this warning lamp on the
instrument panel. Deactivation
I n e x c e p t i o n a l c o n d i t i o n s ( s t a r t i n g a
vehicle which is bogged down, stuck
in snow, on soft ground...), it may be
advisable to deactivate the ASR and
ESP systems, so that the wheels
can move freely and regain grip.
Press the "ESP OFF" button, lo-
cated in the centre of the dash-
board.
If this warning lamp comes
on in the instrument panel
and the indicator lamp on the
button comes on, this indi-
cates that the ASR and ESP
systems are deactivated.
Snow driving assistance
(SNOW MOTION)
Your vehicle has a system to help
driving on snow:
SNOW MOTION.
This automatic system continuously
c h e c k s f o r s i t u a t i o n s o f d i f fi c u l t s u r -
face adhesion that could make it dif-
fi c u l t t o m o v e o f f o r m a k e p r o g r e s s
on deep fresh snow or compacted
snow.
In these situations, the SNOW
MOTION system takes over from
the ASR system by optimising the
amount of wheel slip to provide the
best traction and trajectory control,
even without snow tyres and with or
without chains. For vehicles with Hydractive III+
suspension, manual adjustment of
ground clearance to the intermediate
position improves further the ability
to make progress in deep snow (see
the relevant paragraph).
I n e x t r e m e l y s e v e r e c o n d i t i o n s ( s n o w
on top of ice, sand, deep mud…), it
can be useful to deactivate the
ESP/
ASR systems to allow a degree of
wheel spin and so recover grip.