Operation
Driver assistance systems
Braking and stability systems Brake assist systems The brake assist systems ESC, ABS, BAS, ASR
and EDL only operate when the ignition is
switched on. They contribute significantly to
increasing active safety.
Electronic Stability Control (ESC)
ESC reduces the risk of skidding and increa-
ses the vehicle stability by braking individual
wheels under specific driving conditions. ESC
detects critical handling situations, such as
understeer, oversteer and wheelspin on the
driven wheels. The system stabilises the ve-
hicle by braking individual wheels or by re-
ducing the engine torque.
The ESC has limits. It is important to realise
that the ESC is also subject to the laws of
physics. ESC will not be able to deal with all
situations with which drivers may be faced.
For example, if the road surface changes sud-
denly then ESC will not be useful in all cases.
If the vehicle suddenly enters a section cov-
ered by water, mud or snow then ESC will not
provide assistance in the same way as on dry
ground. If the vehicle loses its grip on the
ground and moves on a film of water (“aqua-
planing”), the ESC will not be able to assist the driver to control the vehicle as the loss of
adherence with the road surface will prevent-
ing braking and steering. If the vehicle is
driven through series of bends at high
speed, the ESC will not always be as effec-
tive: the vehicle reaction to aggressive driv-
ing is not the same as at reduced speeds.
When driving with a trailer, ESC does not pro-
vide the same amount of vehicle control as
without a trailer.
Adjust your speed and driving style to road,
traffic and weather conditions. ESC cannot
push the limits of the laws of physics; im-
prove the transmission available or maintain
the vehicle on the road if a lack of driver at-
tention creates an inevitable situation. Other-
wise, ESC assists in maintaining vehicle con-
trol in extreme situations and uses the move-
ments of the steering made by the driver to
maintain the vehicle moving in the desired
direction. If the vehicle is driven at such a
speed that it will leave the road before ESC
can intervene then the system cannot pro-
vide assistance.
The ABS, BAS, ASR and EDL systems are in-
corporated into the ESC. The ESC is always
on. The ESC should only be turned off using
the ASR button
›››
Fig. 134 when traction is
in s
ufficient. Always remember to turn on the
ASR once more when the vehicle has traction
again. Anti-lock brake system (ABS)
ABS can prevent the wheels from locking dur-
ing braking until just before the vehicle stops
thus helping the driver to steer the vehicle
and maintain control. This means that, even
during full braking, the risk of skidding is re-
duced:
● Press and hold the brake pedal fully. Do not
remove your foot from the brake pedal or re-
duce braking force!
● Do not “pump” the brake pedal, or reduce
braking force!
● Maintain vehicle direction when braking
fully.
● When the brake pedal is released or when
the brake force is reduced, ABS is turned off.
ABS control can be observed by vibration of
the brake pedal and noise. You should never
expect
the ABS to reduce the braking dis-
tance under
any circumstances. This distance
will increase when driving on gravel, recent
snow or on icy and slippery ground.
When driving on loose ground, the all-terrain
configuration of the ABS is automatically
turned on. When ABS is activated, the front
wheels may lock briefly. This shortens the
braking distance in off-road situations as the
wheels are prevented from digging into loose
surfaces. All-terrain ABS only intervenes
when driving in a straight line. When the
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