Cockpit
80Tyre pressure*
The tyre monitor
15) compares wheel revolutions and with this information,
the diameter of each wheel using the ESP sensors. If the diameter of a wheel
changes, the tyre monitor indicator lights . The wheel diameter changes
when:
•
Tyre pressure is insufficient.
•
The tyre structure is damaged.
•
The vehicle is unbalanced because of a load.
•
The wheels of one axle are under more pressure (for example, driving with
a trailer or on extreme slopes).
•
The vehicle is fitted with snow chains.
•
The emergency wheel is fitted.
•
The wheel on one axle is changed. Tyre pressure adjustment
Following the modification to tyre pressure or changing one or more wheels,
the button
⇒fig. 47 must be kept pressed while the ignition is on until an
acoustic signal is heard.
If the wheels are under excessive load (for example, driving with a trailer or
heavy load), the tire pressure must be increased to the recommended value
for a full load (see the sticker on the inside of the fuel flap). If the tyre monitor
system button is pressed the new tyre pressures are confirmed.
The tyre pressure monitor indicator
lights
If the tyre pressure of one wheel is much lower than the value set by the driver
then the indicator lights ⇒.
The tyre pressure monitor indicator flashes
If the tyre pressure indicator flashes, this indicates a fault. Go to the nearest
specialist workshop.
WARNING
•
When the tyre pressure indicator lights, reduce speed immediately and
avoid any sudden manoeuvre or braking. Stop when possible, and check
the tyre pressure and status.
•
The driver is responsible for correct tyre pressure. For this reason, tyre
pressure must be regularly checked.
•
Under certain circumstances (for example, in a sports situation, in
winter conditions or on a dirt track) the tyre monitor indicator may light or
function incorrectly.Note
If the battery is disconnected, the yellow indicator
lights after turning the
ignition on. This should turn off after a brief trip.
15)Depending on the model version
Fig. 47 Central console:
tyre monitor system
button
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Intelligent technology
172Anti-lock brake system and traction control
M-ABS (ABS and TCS)Anti-lock brake system (ABS)
The anti-lock brake system prevents the wheels locking
during braking.The anti-lock brake system (ABS) is an important part of the vehicle's active
safety system.
How the ABS works
If one of the wheels is turns too slowly in relation to the road speed, and is
close to locking, the system will reduce the braking pressure for this wheel.
The driver is made aware of this control process by a pulsating of the brake
pedal and audible noise. This is a deliberate warning to the driver that one or
more of the wheels is tending to lock and the ABS control function has inter-
vened. In this situation it is important to keep the brake pedal fully depressed
so the ABS can regulate the brake application. Do not “pump”.
If you brake hard on a slippery road surface, the best possible control is
retained as the wheels do not lock.
However, ABS will not necessarily guarantee shorter braking distances in all
conditions. The braking distance could even be longer if you brake on gravel
or on fresh snow covering a slippery surface.
WARNING
•
The anti-lock brake system cannot defy the laws of physics. Slippery
and wet roads are dangerous even with ABS! If you notice that the ABS is
working (to counteract locked wheels under braking), you should reduce
speed immediately to suit the road and traffic conditions. Do not let the
extra safety features tempt you into taking any risks when driving.
•
The effectiveness of ABS is also determined by the tyres fitted
⇒ page 221.
•
If the running gear or brakes are mo dified, the effectiveness of the ABS
could be severely limited.
Traction control system (TCS)
The traction control system prevents the drive wheels from
spinning when the car is accelerating.Description and operation of the traction control system during acceleration
(TCS)
TCS reduces engine power to help prevent the drive wheels of front-wheel
drive vehicles losing traction during acceleration. The system works in the
entire speed range in conjunction with ABS. If a malfunction should occur in
the ABS, the TCS will also be out of action.
TCS helps the vehicle to start moving, accelerate and climb a gradient in slip-
pery conditions where this may otherwise be difficult or even impossible.
The TCS is switched on automatically when the engine is started. If necessary,
it may be turned on or off pushing the button on the centre console.
When the TCS is off, the warning lamp is lit. The TCS should normally be left
switched on at all times. Only in exceptional circumstances, when slipping of
the wheels is required, should it be disconnected for example•
With compact temporary spare wheel.
•
When using the snow chains.
•
When driving in deep snow or on loose surfaces
•
When the vehicle is bogged-down, to free it by “rocking.”WARNING (continued)
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