The sensor is part of the ACC» page 110 and Front Assist » page 114systems.
The sensor function may be impaired in the events of one of the following. ▶ The sensor cover is soiled (e.g. with mud, snow etc.).
▶ The area in front of and around the sensor cover is obscured (e.g. by labels,
auxiliary headlights etc.).
▶ When visibility is poor, (e.g. fog, heavy rain, thick snowfall).
If the sensor is covered or dirty, the corresponding message appears in the in-
strument cluster display for the ACC system » page 114, Malfunctions or Front
Assist system » page 116, Malfunctions .WARNING■
If you suspect that the sensor is damaged, deactivate the ACC system and
Front Assist system » page 111, » page 116 . Have the sensor checked by a
specialist garage.■
A collision or damage in the front or lower area of the vehicle could affect
the sensor function - there is risk of accident! Have the sensor checked by
a specialist garage.
■
Do not cover the area in front of and around the sensor cover. This can
lead to impaired function of the sensor - risk of accidents!
CAUTION
Remove the snow with a brush and the ice with a solvent-free de-icer.
Braking and stabilisation systems
Introduction
This chapter contains information on the following subjects:
Stability Control (ESC)
101
Anti-lock braking system (ABS)
101
Engine drag torque control (MSR)
101
Traction control (TCS)
102
Electronic differential lock (EDL and XDS)
102
Brake Assist (HBA)
102
Hill Start Assist (HHC)
102
Multi collision brake (MCB)
103
The brake and stabilization systems are automatically activated each time the
ignition is switched on, unless otherwise indicated.
The error display is in Chapter » page 28, Warning lights .WARNINGThe general information relating to the use of assistance systems must be
observed » page 100, in section Introduction .
Stability Control (ESC)
Read and observe
on page 101 first.
The ESC improves vehicle stability when driving at the limit (e.g. if the vehiclestarts to skid) by braking individual wheels to maintain the desired direction.
If there is a TCS intervention, the indicator light flashes in the instrument
cluster.
Anti-lock braking system (ABS)
Read and observe
on page 101 first.
ABS prevents the wheels locking when braking. Thereby, it helps the driver to
maintain control of the vehicle.
The intervention of the ABS is noticeable from the pulsating movements of
the brake pedal which is accompanied by noises.
When the ABS system is active, do not pump the brakes or lift off the brake
pedal.
Engine drag torque control (MSR)
Read and observe
on page 101 first.
MSR counteracts the tendency of the drive wheels to lock during downshifts
or sudden deceleration (e.g. on icy or an otherwise slippery road surface).
If the drive wheels should lock, then the engine speed is automatically in-
creased. This reduces the braking effect of the engine and the wheels can ro-
tate freely again.
101Assist systems
CAUTIONScrew the jack back to its starting position prior to putting it back in its box -
risk of damage to the box.
Note
The declaration of conformity is included with the jack or the log folder.
Changing a wheel
Preliminary work
For safety's sake, the following instructions must be observed before
changing a wheel on the road.
›
Park the vehicle as far as possible away from the traffic flow - choose a place
with a flat and firm surface.
›
Switch off the engine.
›
For vehicles with manual transmission select1, gear .
›
For vehicles with automatic transmission , place the selector lever in the P
position.
›
Firmly apply the handbrake.
›
Switch on the hazard warning lights and set up the warning triangle at the
prescribed distance.
›
Have all the occupants get out . The passengers should not stand on the
road while the wheel is being changed (they should remain behind a crash
barrier, for instance).
›
Uncouple any trailers.
Changing a wheel
›
Take out the emergency or spare wheel » page 152.
›
Remove the full wheel trim » page 152or caps» page 152 .
›
Loosen the wheel bolts » page 153 » .
›
Jack up the vehicle » page 153 until the wheel that needs changing is clear of
the ground.
›
Unscrew the wheel bolts and place them on a clean surface (cloth, paper,
etc.).
›
Remove the wheel carefully.
›
Attach the spare wheel and slightly screw on the wheel bolts.
›
Lower the vehicle.
›
Tighten the wheel bolts opposite each other using the wheel wrench (“pull- ing crossways”) » page 153.
›Replace the wheel trim
» page 152and caps» page 152 .
When fitting unidirectional tyres, ensure that the direction of rotation is cor-
rect » page 145 .
All bolts must be clean and must turn easily. If screws are corroded and diffi-
cult to move, these must be replaced.WARNING■ Undo the wheel bolts just a little (about one turn), provided the vehicle
has not yet been jacked up. Otherwise the wheel could come loose and fall
off – risk of injury.■
Under no circumstances must the bolts be greased or oiled - cause an ac-
cident.
Subsequent steps
After changing the wheel, the following work should be carried out.
›
Stow the replaced wheel in the well under the floor covering of the luggage
compartment and secure it with a nut.
›
Stow the tool kit in the space provided and secure using the strap.
›
Check tyre pressure on the mounted wheel and adjust if necessary and, with
vehicles with tyre pressure monitoring, save the tyre pressure values in the
system » page 117 .
›
Have the tightening torque of the wheel bolts checked as soon as possible.
The prescribed tightening torque is 120 Nm.
Change the damaged wheel or consult a specialist garage about repair possi-
bilities.
WARNINGTightening torque which is too high can damage the threads and this can
result in permanent deformation of the contact surfaces on the rim. Where
tightening torque is too low, the wheels may become loose while driving -
risk of accident. Therefore drive cautiously and only at a moderate speed
until the tightening torque has been checked.151Emergency equipment, and self-help
