
Active Lane Keeping Assist
General notes
Active Lane Keeping Assist monitors the area in
front of your vehicle by means of multifunction
camera :at the top of the windscreen. Various
different areas to the front, rear and side of your vehicle are also monitored with the aid of the
radar sensor system. Active Lane Keeping
Assist detects lane markings on the road and
can warn you before you leave your lane unin-
tentionally. If you do not react to the warning, a
lane-correcting brake application can bring the
vehicle back into the original lane.
This function is available in a speed range
between 60 km/h and 200 km/h.
Important safety notes Active Lane Keeping Assist can neither reduce
the risk of an accident if you fail to adapt your
driving style nor override the laws of physics.
Active Lane Keeping Assist cannot take account of road and weather conditions. It may not rec-
ognise certain road and traffic conditions.
Active Lane Keeping Assist is only an aid. You
are responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good time
and for staying in lane.
Active Lane Keeping Assist cannot continuously
keep your vehicle in its lane. G
WARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings. In such cases, Active Lane Keeping Assist
can:
R give an unnecessary warning and then
make a course-correcting brake application
to the vehicle
R neither give a warning nor intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, especially
if Active Lane Keeping Assist alerts you. Ter-
minate the intervention in a non-critical driv-
ing situation.
The system may be impaired or may not function in the following situations:
R poor visibility, e.g. due to insufficient illumi-
nation of the road, or due to snow, rain, fog or
spray
R glare, e.g. from oncoming traffic, the sun or
reflection from other vehicles (e.g. if the road
surface is wet)
R the windscreen is dirty, misted up, damaged
or covered, for instance by a sticker, in the
vicinity of the camera
R the radar sensors in the front or rear bumpers
or the radiator trim are dirty, e.g. obscured by
snow
R no or several, unclear lane markings are pres-
ent for one lane, e.g. in a construction area
R the lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow
R the distance to the vehicle in front is so small
that the lane markings cannot be detected
R the lane markings change quickly, e.g. lanes
branch off, cross one another or merge
R the road is very narrow and winding
R there are highly variable shade conditions on
the roadway
If no vehicle is detected in the adjacent lane and broken lane markings are detected, no lane-cor-
recting brake application is made.
Warning vibration through the steering
wheel A warning may be given if a front wheel passes
over a lane marking. It will warn you by means of intermittent vibration in the steering wheel for
up to 1.5 seconds. 216
Driving systemsDriving and pa
rking

Important safety notes
G
WARNING
Operating the integrated information systems and communications equipment in the vehicle
while driving will distract you from traffic con-
ditions. You could then lose control of the
vehicle. There is a risk of an accident.
Only operate these devices if road traffic con-
ditions permit. If you are unsure about the
surrounding conditions, pull over to a safe
location and make entries only while the vehi-
cle is stationary.
You must observe the legal requirements for the country in which you are currently driving whenoperating the on-board computer. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognise function
restrictions relevant to safety. The operating
safety of your vehicle may be impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
If the operating safety of your vehicle is
impaired, park the vehicle safely as soon as pos- sible. Contact a qualified specialist workshop.
The on-board computer shows only messages or warnings from certain systems on the multi-
function display. You should therefore make
sure your vehicle is operating safely at all times.
For an overview, see the instrument cluster illus-
tration (Y page 34).
HYBRID vehicles: make sure that you read the
separate Owner's Manual. Otherwise, you may
fail to recognise dangers. Displays and operation
Instrument cluster lighting
The lighting on the instrument cluster, on the
displays and the controls in the vehicle interior
can be adjusted using brightness control
knob :.
X Turn brightness control knob :up or down.
If you turn the light switch (Y page 115) to the
T, ÃorL position, the brightness
will depend upon the brightness of the ambi-
ent light.
i The light sensor on the instrument cluster
automatically controls the brightness of the
multifunction display.
In daylight, the displays on the instrument
cluster are lit. A dimming function is not pos-
sible in daylight. Speedometer with segments
The speedometer is divided into segments
depending on the vehicle's equipment.
The segments in the speedometer indicate
which speed range is available.
R Cruise control enabled (Y page 174):
The segments light up from the stored speed to the end of the scale or to a permanently set
speed limitation.
R Variable SPEEDTRONIC enabled
(Y page 176):
The segments light up from the start of the
scale to the selected speed limitation.
R DISTRONIC PLUS enabled (Y page 178):
One or two segments in the stored speed
range light up.
R DISTRONIC PLUS detects a vehicle in front
moving more slowly than the stored speed: 228
Displays and operationOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions #
Check Check
brake
brakepad
padwear
wear The brake pads/linings have reached their wear limit.
X Consult a qualified specialist workshop. G
Inoperative Inoperative Vehicles with Audio 20 multimedia system:
Malfunction of one or more main functions of the MB Contact system.
X Consult a qualified specialist workshop. G
Inoperative Inoperative Vehicles with COMAND Online multimedia system:
Malfunction of one or more main functions of the Mercedes connect
me system.
X Consult a qualified specialist workshop. Collision Preven‐ Collision Preven‐
tion Assist Plus tion Assist Plus
currently unavaila‐ currently unavaila‐
ble ble
See
SeeOwner's
Owner's Man‐
Man‐
ual
ual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R The radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio stations or other sources of electromagnetic radiation
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
disappears.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 167).
X Restart the engine. Collision Preven‐ Collision Preven‐
tion Assist Plus tion Assist Plus
inoperative inoperative COLLISION PREVENTION ASSIST PLUS is inoperative due to a mal-
function. Adaptive Brake Assist may also have failed.
X Consult a qualified specialist workshop immediately. PRE-SAFE inopera‐ PRE-SAFE inopera‐
tive See Owner's tive See Owner's
Manual Manual
Important PRE-SAFE
®
functions have failed. All other occupant safety
systems, e.g. airbags, remain available.
X Consult a qualified specialist workshop immediately. Display
messages
255On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions PRE-SAFE Functions
PRE-SAFE Functions
currently limited currently limited
See Owner's Manual See Owner's Manual
PRE
‑SAFE ®
PLUS or PRE‑ SAFE®
Brake is temporarily inoperative.
Possible causes:
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 stations or
other sources of electromagnetic radiation
R The system is outside the operating temperature range
R The on-board voltage is too low.
R Mercedes-AMG vehicles: ESP ®
is deactivated
Once the causes listed above no longer apply, the display message
disappears.
PRE ‑SAFE ®
PLUS and PRE ‑SAFE®
Brake are operational again.
If the display message does not disappear:
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 167).
X Restart the engine.
X Mercedes-AMG vehicles: reactivate ESP ®
(Y page 75). PRE-SAFE Functions PRE-SAFE Functions
limited limited
See
See Owner's
Owner's
Manual
Manual PRE
‑SAFE ®
PLUS or PRE‑ SAFE®
Brake is unavailable due to a mal-
function. BAS PLUS with Cross-Traffic Assist may also have failed.
X Consult a qualified specialist workshop immediately. 256
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Radar
Radar
sensors
sensors dirty
dirty
See Owner's Manual
See Owner's Manual The radar sensor system is malfunctioning.
Possible causes:
R Dirt on sensors
R Heavy rain or snow
R Driving on inter-urban roads without traffic or infrastructure, e.g. in
desert-like areas
At least one driving system or driving safety system is malfunctioning
or is temporarily unavailable:
R PRE-SAFE ®
PLUS
R COLLISION PREVENTION ASSIST PLUS
R Active Lane Keeping Assist
R Active Blind Spot Assist
R DISTRONIC PLUS with Steering Assist and Stop&Go Pilot
If the front radar system sensor is dirty, Active Blind Spot Assist will
not perform a course-correcting brake application.
Once the cause of the problem is no longer present, the driving sys-
tems and driving safety systems will be available again. The display
message disappears.
If the display message does not disappear:
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 167).
X Switch off the engine.
X Clean all sensors (Y page 335).
X Restart the engine.
The display message disappears. 6
Restraint sys. mal‐ Restraint sys. mal‐
function Consult function Consult
workshop workshop The restraint system is malfunctioning. The
6warning lamp also
lights up on the instrument cluster.
G WARNING
The airbags or belt tensioners may either be triggered unintentionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury!
X Consult a qualified specialist workshop immediately.
Further information about the restraint system (Y page 41).6
Front left malfunc‐ Front left malfunc‐
tion Consult work‐ tion Consult work‐
shop shop
orFront right
Front right
malfunction
malfunction Consult
Consult
workshop
workshop The front left or right restraint system is malfunctioning. The
6
warning lamp also lights up on the instrument cluster.
G WARNING
The airbags or belt tensioners may either be triggered unintentionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury!
X Consult a qualified specialist workshop immediately. Display
messages
257On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions X
Consult a qualified specialist workshop immediately.
Further information on the automatic front-passenger front airbag
deactivation system (Y page 49).Lights
Display messages
Possible causes/consequences and
M
MSolutions b
Left dipped beam Left dipped beam
(Example) The bulb in question is faulty.
X Consult a qualified specialist workshop.
or X Check whether you are permitted to replace the bulb yourself
(Y page 122).
i LED light bulbs: the display message for the corresponding lamp
only appears when all the LEDs in the lamp have failed. b
Active Active
Light
LightSystem
System
inoperative
inoperative The active light function is malfunctioning.
X Consult a qualified specialist workshop. b
Intell. Light Sys‐ Intell. Light Sys‐
tem inoperative tem inoperative The Intelligent Light System is malfunctioning. The lighting system
continues to function properly without the functions of the Intelligent
Light System.
X Consult a qualified specialist workshop. b
Malfunction Malfunction
See
SeeOwn‐
Own‐
er's Manual
er's Manual The exterior lighting is faulty.
X Consult a qualified specialist workshop. Vehicles with trailer tow hitch: a fuse may have blown.
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling (Y page 167).
X Check the fuses (Y page 354).
X If necessary, replace the blown fuse. Observe the warning notes as
you do so.
If the display message remains on show:
X Consult a qualified specialist workshop. b
AUTO lights inoper‐ AUTO lights inoper‐
ative ative The light sensor is malfunctioning.
X Consult a qualified specialist workshop. b
Switch off lights Switch off lights You are leaving the vehicle and the lights are switched on. A warning
tone also sounds.
X Turn the light switch to the Ãposition. Display
messages
261On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Lane
Lane
Keeping
Keeping Assist
Assist
currently unavaila‐
currently unavaila‐
ble ble See
SeeOwner's
Owner's Man‐
Man‐
ual
ual orActive Lane
Active Lane
Keeping Assist cur‐
Keeping Assist cur‐
rently unavailable rently unavailable
See Owner's Manual See Owner's Manual Lane Keeping Assist or Active Lane Keeping Assist is deactivated and
temporarily inoperative.
Possible causes:
R The windscreen is dirty in the camera's field of vision
R Visibility is impaired due to heavy rain, snow or fog
R There have been no lane markings for an extended period
R The lane markings are worn, dark or covered, e.g. by dirt or snow
Once the causes listed above no longer apply, the display message
disappears.
Lane Keeping Assist or Active Lane Keeping Assist is operational
again.
If the display message does not disappear:
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 167).
X Clean the windscreen. Lane Lane
Keeping
Keeping Assist
Assist
inoperative
inoperative or
Active
Active Lane
LaneKeeping
Keeping
Assist inoperative
Assist inoperative Lane Keeping Assist or Active Lane Keeping Assist is faulty.
X Consult a qualified specialist workshop. Blind Spot Assist
Blind Spot Assist
currently unavaila‐ currently unavaila‐
ble ble
See
SeeOwner's
Owner's Man‐
Man‐
ual
ual orActive Blind
Active Blind
Spot Assist cur‐
Spot Assist cur‐
rently unavailable rently unavailable
See Owner's Manual See Owner's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily inoperative.
Possible causes:
R The radar sensor system is outside the operating temperature range
R The radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio stations or
other sources of electromagnetic radiation
Once the causes listed above no longer apply, the display message
disappears.
Blind Spot Assist or Active Blind Spot Assist is operational again.
If the display message does not disappear:
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 167).
X Restart the engine. Blind Spot Assist Blind Spot Assist
not available when not available when
towing a trailer towing a trailer
See Owner's Manual See Owner's Manual
or
Active Blind Active Blind
Spot Assist not
Spot Assist not
available when tow‐ available when tow‐
ing a trailer See ing a trailer See
Owner's Manual Owner's Manual Blind Spot Assist or Active Blind Spot Assist is deactivated during
trailer-towing.
You have established the electrical connection between the trailer and
your vehicle.
X Press aon the steering wheel to confirm the display message. 268
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions The HOLD function is deactivated. When the brake pedal is firmly
depressed, an activation condition is no longer fulfilled.
A warning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 186). DISTRONIC PLUS off DISTRONIC PLUS off DISTRONIC PLUS has been deactivated (Y
page 178).
If it was not deactivated by the driver, a warning tone also sounds. DISTRONIC PLUS
DISTRONIC PLUS
available again available again DISTRONIC PLUS is operational again after having been temporarily
unavailable. You can now reactivate DISTRONIC PLUS (Y
page 178).DISTRONIC PLUS cur‐ DISTRONIC PLUS cur‐
rently unavailable rently unavailable
See Owner's Manual See Owner's Manual DISTRONIC PLUS is temporarily inoperative.
Steering Assist and Stop&Go Pilot are also temporarily inoperative.
Possible causes:
R The radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio stations or other sources of electromagnetic radiation
R The system is outside the operating temperature range
R The on-board voltage is too low.
A warning tone also sounds.
Once the causes listed above no longer apply, the display message
disappears.
DISTRONIC PLUS is operational again.
If the display message does not disappear:
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 167).
X Restart the engine. DISTRONIC DISTRONIC
PLUS
PLUSinop‐
inop‐
erative
erative DISTRONIC PLUS is malfunctioning.
The following may have also failed:
R BAS PLUS with Cross-Traffic Assist
R PRE-SAFE ®
Brake
A warning tone also sounds.
X Consult a qualified specialist workshop. DISTRONIC PLUS sus‐ DISTRONIC PLUS sus‐
pended pended You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
X Remove your foot from the accelerator pedal. DISTRONIC PLUS
DISTRONIC PLUS
- - - mph - - - mph An activation condition for DISTRONIC PLUS is not fulfilled.
X Check the activation conditions for DISTRONIC PLUS (Y page 178).DISTRONIC PLUS and
DISTRONIC PLUS and
SPEEDTRONIC inoper‐ SPEEDTRONIC inoper‐
ative ative DISTRONIC PLUS and SPEEDTRONIC are faulty. A warning tone also
sounds.
Steering Assist and Stop&Go Pilot are therefore also unavailable.
X Consult a qualified specialist workshop. 270
Display
messagesOn-board computer and displays