Driving safety systems
Driving safety systems overview
In this section, you will find information about the following driving safety systems:
R ABS (Anti-lock BrakingSystem)
(Y page 72)
R BAS (Brake Assist System) (Y page 73)
R COLLISION PREVENTION ASSIST (distance
warning function and adaptive Brake
Assist) (Y page 73)
R COLLISION PREVENTION ASSIST PLUS
(Y page 73)
R Adaptive brake lamps (Y page 76)
R ESP ®
(E lectronic StabilityProgram)
(Y page 76)
R EBD (electronic brake forcedistribution)
(Y page 80)
R ADAPTIVE BRAKE (Y page 80)
R STEER CONTROL (Y page 81)Important safety notes
If you fail to adapt your driving style or if you
are inattentive, the driving safety systems can
neither reduce the risk of accident nor over-
ride the laws of physics. Driving safety sys-
tems are merely aids designed to assist driv- ing. You are responsible for the distance to
the vehicle in front, for vehicle speed and forbraking in good time. Always adapt your driv- ing style to suit the prevailing road, weather
and traffic conditions and maintain a safe dis-
tance from the vehicle in front. Drive care-
fully.
i The driving safety systems described only
work as effectively as possible when there
is adequate contact between the tyres and
the road surface. Pay particular attention to the information regarding tyres, recom-
mended minimum tyre tread depths etc. inthe "Wheels and tyres" section
(Y page 352). In wintry driving conditions, always use
winter tyres (M+S tyres) and, if necessary,
snow chains. Only in this way will the driv-
ing safety systems described in this section
work as effectively as possible. ABS (Anti-lock Braking System)
General notes ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the vehi- cle when braking.
The ! ABS warning lamp in the instrument
cluster lights up when the ignition is switched on. It goes out when the engine is running.
Important safety notes i
Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 72). G
WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid- ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
If ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information on the ABS warning lamp (Y page 289) and
display messages which may be shown in the
instrument cluster (Y page 255).
ABS works from a speed of about
8 km/hupwards, regardless of road-surface
conditions. ABS works on slippery surfaces,
even when you only brake gently. 72
Driving safety syste
msSafety
Safety systems
Display messages
Possible causes/consequences and
M
MSolutions !÷
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual ABS (Anti-lock Braking System), ESP
®
(Electronic Stability Pro-
gram), BAS (Brake Assist), PRE-SAFE ®
, the HOLD function, Hill
Start Assist and ESP ®
trailer stabilisation are temporarily unavail-
able.
The adaptive brake lights and COLLISION PREVENTION ASSIST/
COLLISION PREVENTION ASSIST PLUS may also have failed.
In addition, the ÷,åand! warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
Possible causes:
R self-diagnosis is not yet complete
R the on-board voltage may be insufficient
G WARNING
The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements, at a speed above 20 km/h.
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop. !÷
inoperative See inoperative See
Owner's Manual Owner's Manual ABS, ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, Hill Start Assist
and ESP ®
trailer stabilisation are unavailable due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST/
COLLISION PREVENTION ASSIST PLUS may also have failed.
In addition, the J,÷,åand! warning lamps light up
in the instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING Display messages
255On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions ÷
inoperative See inoperative See
Owner's Manual Owner's Manual ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, Hill Start Assist and
ESP ®
trailer stabilisation are not available due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST/
COLLISION PREVENTION ASSIST PLUS may also have failed.
In addition, the ÷andå warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance may thus increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Drive on carefully.
X Visit a qualified specialist workshop. T!
÷
inoperative See inoperative See
Owner's Manual Owner's Manual EBD (electronic brake force distribution), ABS, ESP
®
, BAS, PRE-
SAFE ®
, the HOLD function, Hill Start Assist and ESP ®
trailer sta-
bilisation are unavailable due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST/
COLLISION PREVENTION ASSIST PLUS may also have failed.
In addition, the ÷,åand! warning lamps light up in the
instrument cluster and a warning tone sounds.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affec-ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. Display
messages
257On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R the front bumper is dirty
R the function is impaired due to heavy rain or snow
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation
R AMG vehicles: ESP ®
is deactivated
R the system is outside the operating temperature range
R The on-board voltage is too low.
Once the causes listed above no longer apply, the display message goes out.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 179).
X Clean the front bumper (Y page 326).
X Restart the engine.
X AMG vehicles: reactivate ESP ®
(Y page 78). Collision Preven‐ Collision Preven‐
tion Assist Plus tion Assist Plus
inoperative
inoperative COLLISION PREVENTION ASSIST PLUS is malfunctioning. The dis-
tance warning signal may also have failed.
X Visit a qualified specialist workshop. 262
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions PRE-SAFE
PRE-SAFE
Functions cur‐ Functions cur‐
rently rently
limited
limited See
See
Owner's Manual
Owner's Manual Adaptive Brake Assist is temporarily inoperative. Possible causes:
R the front bumper is dirty
R the function is impaired due to heavy rain or snow
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation
R AMG vehicles: ESP ®
is deactivated
R the system is outside the operating temperature range
R the on-board voltage is too low.
Once the causes listed above no longer apply, the display message goes out.
Adaptive Brake Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 179).
X Clean the front bumper (Y page 326).
X Restart the engine.
X AMG vehicles: reactivate ESP ®
(Y page 78). PRE-SAFE PRE-SAFE
Functions limited Functions limited
See Owner's Manual See Owner's Manual Adaptive Brake Assist is faulty. The distance warning signal may
also have failed.
X Visit a qualified specialist workshop. PRE-SAFE PRE-SAFE
inoperative See inoperative See
Owner's Manual Owner's Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. ü If this symbol appears in the multifunction display, a seat belt
tongue has been inserted into a rear seat belt buckle.
Further information on the status indicator for the rear seat belts
(Y page 48). Display
messages
263On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions Blind Spot Assist is deactivated while towing a trailer.
You have established the electrical connection between the trailer
and your vehicle.
X Press aon the steering wheel to confirm the display mes-
sage. Blind Spot Assist Blind Spot Assist
inoperative inoperative Blind Spot Assist is faulty.
The yellow
9indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Park Park
Assist
Assist cancel‐
cancel‐
led
led The driver's door is open and the driver's seat belt has not been
fastened.
X Repeat the parking process with the seat belt fastened and the
driver's door closed. You inadvertently touched the multifunction steering wheel while
steering intervention was active.
X While steering intervention is active, make sure not to touch the
multifunction steering wheel. The vehicle has started to skid and ESP
®
has intervened.
X Use Active Parking Assist again later (Y page 210).Park Park
Assist
Assist inoper‐
inoper‐
ative
ative You have just carried out a large number of turning or parking
manoeuvres.
Active Parking Assist will become available again after approx-
imately ten minutes (Y
page 210).
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Switch off and restart the engine.
If the display message continues to be displayed: X Visit a qualified specialist workshop. PARKTRONIC is faulty.
X Visit a qualified specialist workshop. DISTRONIC PLUS off DISTRONIC PLUS off DISTRONIC PLUS has been deactivated (Y
page 193). If it was
deactivated automatically, a warning tone also sounds. DISTRONIC PLUS
DISTRONIC PLUS
available again available again DISTRONIC PLUS is operational again after having been tempo-
rarily unavailable. You can now reactivate DISTRONIC PLUS
(Y
page 193). Display
messages
277On-board computer and displays Z
Tyres
Display messages
Possible causes/consequences and
M
MSolutions Tyre pressure
Tyre pressure
Check tyres Check tyres The tyre pressure loss warning system has detected a significant
loss in pressure.
A warning tone also sounds.
Possible causes:
R you have changed the positions of the wheels and tyres or fitted
new wheels and tyres.
R the tyre pressure in one or more tyres is not correct.
G WARNING
Underinflated tyres pose the following risks:
R the tyres may burst, especially as the load and vehicle speed
increase
R the tyres may wear excessively and/or unevenly, which may
greatly impair tyre traction
R the driving characteristics, as well as steering and braking, may
be greatly impaired
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do so.
X Secure the vehicle to prevent it from rolling away (Y page 179).
X Check the tyres and, if necessary, follow the instructions for a
flat tyre (Y page 334).
X Check the tyre pressures and, if necessary, correct the tyre
pressure.
X Restart the tyre pressure loss warning system when the tyre
pressure is correct (Y page 358).Check tyre pres‐ Check tyre pres‐
sures sures
then restart Run then restart Run
Flat Indicator Flat Indicator The tyre pressure loss warning system generated a display mes-
sage and has not been restarted since.
X Set the correct tyre pressure in all four tyres.
X Restart the tyre pressure loss warning system (Y page 358).Run Flat Indicator Run Flat Indicator
inoperative
inoperative The tyre pressure loss warning system is faulty.
X Visit a qualified specialist workshop. Rectify tyre pres‐
Rectify tyre pres‐
sure sure The tyre pressure is too low in at least one of the tyres, or the tyre
pressure difference between the wheels is too great.
X Check the tyre pressures at the next opportunity (Y page 358).
X If necessary, correct the tyre pressure.
X Restart the tyre pressure monitor (Y page 360).280
Display
messagesOn-board computer and displays