2016 MERCEDES-BENZ C-Class SEDAN Light on sensor

The detection of obstacles can be impaired in
the case of:
Rthere is dirt on the sensors or anything else
covering the sensors
Rpoor visibility, e.g. due to rain, snow or spray
Vehicles in the monitoring range are then not
indicated.
Active Blind Spot Assist may not detect narrow
vehicles, such as motorcycles or bicycles, or
may only detect them too late.
If the lanes are narrow, vehicles driving in the
lane beyond the lane next to your vehicle may be
indicated, especially if the vehicles are not driv- ing in the middle of their lane. This may be the
case if there are vehicles at the inner edge of
your lane.
Due to the nature of the system:
Rwarnings may be issued in error when driving
close to crash barriers or similar solid lane
borders.
Rwarnings may be interrupted when driving
alongside particularly long vehicles, e.g.
trucks, for a prolonged time.
Warning display
:Warning display
Active Blind Spot Assist is not operational at
speeds below approximately 20 mph (30 km/h).
Vehicles in the monitoring range are then not
indicated.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h) , warning lamp :on the correspond-
ing side lights up red. This warning is always
emitted when a vehicle enters the blind spot
monitoring range from behind or from the side.
When you overtake a vehicle, the warning only
occurs if the difference in speed is less than
7 mph (12 km/h). If you select the reverse gear, Active Blind Spot
Assist is not operational.
The brightness of the warning lamps is auto-
matically adapted to the brightness of the sur-
roundings.
When Active Blind Spot Assist is activated, gray
radar waves propagating backwards appear
next to the vehicle in the assistance display in
the multifunction display. Above a speed of
20 mph (30 km/h), the color of the radar waves
in the assistance display changes to green
;.
Active Blind Spot Assist is then ready for use.
Visual and acoustic collision warning
If you switch on the turn signals to change lanes and a vehicle is detected in the side monitoring
range, you receive a visual and acoustic collision warning. You will then hear a double warning
tone and red warning lamp :flashes. If the turn
signal remains on, detected vehicles are indica-
ted by the flashing of red warning lamp :.
There are no further warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of a lat-
eral collision in the monitoring range, a course-
correcting brake application is carried out. This
is meant to assist you in avoiding a collision.
GWARNING
A course-correcting brake application cannot always prevent a collision. There is a risk of an
accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makes a course-correcting brake appli-
cation. Always maintain a safe distance at the
sides.
Driving systems221
Driving and parking
Z

If a course-correcting brake application occurs,
red warning lamp:flashes in the exterior mir-
ror and a dual warning tone sounds. In addition,
display ;underlining the danger of a side col-
lision appears in the multifunction display.
In very rare cases, the system may make an
inappropriate brake application. A course-cor-
recting brake application may be interrupted at
any time if you steer slightly in the opposite
direction or accelerate.
The course-correcting brake application is avail-
able in the speed range between 20 mph
(30 km/h) and 120 mph (200 km/h).
Either no braking application, or a course-cor-
recting brake application adapted to the driving
situation occurs if:
Rthere are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehicle.
Ra vehicle approaches you too closely at the
side.
Ryou have adopted a sporty driving style with
high cornering speeds.
Ryou clearly brake or accelerate.
Ra driving safety system intervenes, e.g. ESP®
or PRE-SAFE®Brake.
RESP®is switched off.
Ra loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist
XMake sure that Active Blind Spot Assist is
activated in the on-board computer
(
Ypage 248).
XTurn the SmartKey to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors light
up red for approximately 1.5 seconds. Gray
radar waves propagating backwards appear
next to the vehicle in the assistance display in
the multifunction display.
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 windshield. 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 application of the brakes can
bring the vehicle back into the original lane.
Important safety notes
If you fail to adapt your driving style, Active Lane
Keeping Assist can neither reduce the risk of
accident nor override the laws of physics. Active
Lane Keeping Assist cannot take account of
road and weather conditions. It may not recog-
nize traffic situations. 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 your lane.
Active Lane Keeping Assist cannot continuously
keep your vehicle in its lane.
GWARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings.
In such cases, Active Lane Keeping Assist
can:
Rgive an unnecessary warning and then
make a course-correcting brake application
to the vehicle
Rnot give a warning or intervene
There is a risk of an accident.
222Driving systems
Driving and parking

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
if:
Rthere is poor visibility, e.g. due to insufficient
illumination of the road, or due to snow, rain,
fog or spray
Rthere is glare, e.g. from oncoming traffic, the
sun or reflections (e.g. when the road surface is wet)
Rthe windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in the vicin-
ity of the camera
Rthe radar sensors in the front or rear bumpers
or the radiator trim are dirty, e.g. obscured by
snow
Rthere are no, several or unclear lane markings
for a lane, e.g. in areas with road construction
work
Rthe lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is too small
and the lane markings thus cannot be detec-
ted
Rthe lane markings change quickly, e.g. lanes
branch off, cross one another or merge
Rthe road is narrow and winding
Rthere are strong shadows cast on the road
If no vehicle is detected in the adjacent lane and
broke
n lane markings are detected, no lane-cor-
recting brake application is made.
Warning vibration in 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.
Lane -correcting brake application
If you leave your lane, under certain circumstan-
ces the vehicle will brake briefly on one side.
This is meant to assist you in bringing the vehicle
back to the original lane.
GWARNING
A lane-correcting brake application cannot
always bring the vehicle back into the original lane. There is a risk of an accident.
Always steer, brake or accelerate yourself,
especially if Active Lane Keeping Assist warns
you or makes a lane-correcting brake appli-
cation.
If a lane-correcting brake application occurs,
display :appears in the multifunction display.
The brake application also slightly reduces vehi-
cle speed.
This function is available in the range between
40 mph and 120 mph (60 km/h and 200 km/h).
A lane-correcting brake application can be made after driving over a lane marking detected as
being solid or broken. Before this, a warning
must be given by means of intermittent vibration
in the steering wheel. In addition, a lane with
lane markings on both sides must be recog-
nized.
In the case of a broken lane marking being
detected, a lane-correcting brake application
can only be made if a vehicle has been detected
in the adjacent lane. Oncoming vehicles, over-
taking vehicles and vehicles in adjacent lanes
can be detected.
iA further lane-correcting brake application
can only occur after your vehicle has returned
to the original lane.
No lane-correcting brake application occurs if:
Ryou clearly and actively steer, brake or accel- erate.
Ryou cut the corner on a sharp bend.
Ryou have switched on the turn signal.
Ra driving safety system intervenes, e.g. ESP®,
PRE-SAFE®Brake or Active Blind Spot Assist.
Driving systems223
Driving and parking
Z

Important safety notes
GWARNING
If you operate information systems and com-
munication equipmen tintegrate din th evehi-
cle while driving ,you will be distracte dfrom
traffic conditions. You could also lose control
of th evehicle. Ther eis aris kof an accident.
Only operate th eequipmen twhen th etraffic
situation permits. If you are no tsur ethat this
is possible ,park th evehicl epayin gattention
to traffic condition sand operate th eequip-
men twhen th evehicl eis stationary.
You must observ eth elegal requirements for th e
country in whic hyou are currentl ydriving when
operating th eon-board computer.
PLUG-IN HYBRID vehicles only :
GWARNING
If th einstrumen tcluste rhas faile dor mal-
functioned, you may no trecognize function
restriction sin systems relevan tto safety. The
operating safet yof your vehicl emay be
impaired .Ther eis aris kof an accident.
Pull ove ras soo nas it is saf eto do so and
consult aqualified specialist workshop.
All vehicles, excep tPLUG-IN HYBRID vehi-
cles:
GWARNIN G
If th einstrumen tcluste rhas faile dor mal-
functioned, you may no trecognize function
restriction sin systems relevan tto safety. The
operating safet yof your vehicl emay be
impaired .Ther eis aris kof an accident.
Drive on carefully. Hav eth evehicl echecke d
at aqualified specialist workshop immedi-
ately.
If th eoperating safet yof your vehicl eis
impaired ,pull ove ras soo nas it is saf eto do so.
Contac t aqualified specialist workshop.
The on-board computer only shows message sor
warning sfrom certain systems in th emultifunc-
tion display. You should therefor emak esur e
your vehicl eis operating safely at all times .Fo
ran overview, see th einstrumen tpanel illus-
tration (
Ypage 36).
Displays and operation
Instrument cluster lighting
The lighting in th einstrumen tcluster, in th edis-
plays and th econtrol sin th evehicl einterior can
be adjusted usin gbrightness control knob :.
XTurn brightness control knob :up or down .
If you tur nth eligh tswitch (Ypage 118) to th e
T, ÃorL position ,th ebrightness
will depend upon th ebrightness of th eambi -
en tlight.
iThe ligh tsensor in th einstrumen tcluste r
automatically control sth ebrightness of th e
multifunction display.
In daylight, th edisplays in th einstrumen t
cluste rare illuminated. Adimming function is
no tpossibl ein daylight.
Speedometer with segments
The speedometer is divided int osegments on
Mercedes-AM Gvehicles or vehicles wit h
DISTRONI CPLUS.
The segments in th espeedometer indicat e
whic hspee drange is available.
RCruis econtrol activated (Ypage 185):
The segments ligh tup from th estore dspee d
to th etype-tested maximum speed.
RDISTRONI CPLU Sactivated (Ypage 186):
On eor two segments in th eset spee drange
ligh tup.
RDISTRONI CPLU Sdetects avehicl ein fron t
that is driving at aslower spee dthan th e
store dspeed:
Displays and operation235
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
The yellow!warning lamp lights up and th ered F (USAonly)
or ! (Canada only) indicator lamp flashes .
It is no tpossibl eto apply th eelectric parking brak emanually.
XShift th etransmission to position P.
XVisitaqualified specialist workshop .
$(USA
only)
J( Canada
only)
Check Brake Fluid
Level
There is no tenough brak eflui din th ebrak efluid reservoir .
In addition ,th e$ (USAonly) or J(Canada only) warning lamp
lights up in th einstrumen tcluste rand awarning tone sounds.
GWARNIN G
The braking effec tmay be impaired.
There is aris kof an accident.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinu edrivin g
under any circumstances.
XSecur eth evehicl eagainst rollin gaway (Ypage 177).
XConsult aqualified specialist workshop .
XDo notadd brak efluid .This does no tcorrec tth emalfunction .
#
CheckBrakePadWear
The brak epads/linings hav ereached their wear limit.
US Aonly: th e$ red brak esystem warning lamp is lit while th e
engin eis running.
XVisit aqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunctioning .
XVisitaqualified specialist workshop .
Collision Preven‐tionAssist Plu sCurrently Unavaila‐ble See Operator' sManual
COLLISION PREVENTION ASSIST PLU Sis temporarily no toperational.
Possibl ecauses are:
Rth eradar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti cradiation emitted by nearby TV or radi ostation sor
other source sof electromagneti cradiation .
Rthesystem is outside th eoperating temperature range.
Rth eon-boar dvoltag eis to olow.
Whe nth ecauses state dabov eno longer apply, th edisplay message
disappears.
COLLISION PREVENTION ASSIST PLU Sis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 177).
XRestart th eengine.
Display messages26 1
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
RadarSensorsDirtySee Operator' sMan ‐ual
At least on eof th efollowin gdrivin gsystems or drivin gsafet ysystems
is temporarily restricted or inoperative:
RPRE-SAF E®PLUS
RPRE-SAF E®Brake
RCOLLISION PREVENTION ASSIST PLU S
RActive LaneKeepin gAssis t
RActive Blind Spot Assis t
RDISTRONICPLU Swit hSteering Assis tand Stop&Go Pilo t
If th eradar sensor system in fron tis dirty, Active Blind Spot Assis twill
no tperfor m acourse-correcting brak eapplication .
Possibl ecauses are:
Rth esensor sin th eradiato rtrim and/o rin th ebumpers are dirty
Rth efunction of th edrivin gsystem or drivin gsafet ysystem is
impaire ddue to heav yrain or snow
A warning tone also sounds.
Whe nth ecauses state dabov eno longer apply, th edisplay message
disappears. Al ldrivin gsystems or drivin gsafet ysystems are operative
again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 177).
XSwitchoff th eengine.
XClean th esensor sin th efollowin glocation s (Ypage 339):
Rin theradiato rtrim
Rin th efron tbumper
Rin th erear bumper, particularly in th emiddle of th erear bumper
XRestart th eengine.
The display message disappears.
6
SRSMalfunctionSer ‐viceRequired
The restrain tsystem is faulty. The 6warning lamp also lights up in
th einstrumen tcluster.
GWARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th eevent of an accident, may no tbe triggered .
There is an increased ris kof injury.
XVisit aqualified specialist workshop immediately.
Fo rfurther information about th erestrain tsystem, see (
Ypage 46).
Display messages263
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
XVisitaqualified specialist workshop immediately.
Fo rfurther information about th eOccupant Classification System, see
(
Ypage 54).
Lights
Display messagesPossible causes/consequences and MSolutions
b
CheckLeftLowBeam(Example)
The correspondin gbulb is faulty.
XVisit aqualified specialist workshop .
or
XChec kwhether you are permitte dto replace th ebulb yourself
(Ypage 122).
iLE Dligh tsources: th edisplay message for th ecorrespondin g
lamp only appear swhen all th eLEDs in th elamp hav efailed.
b
Active HeadlampsInoperative
The active ligh tfunction is faulty.
XVisit aqualified specialist workshop .
b
Malfunction SeeOperator’sManual
The exterio rlighting is defective.
XVisit aqualified specialist workshop .
b
AutoLam pFunctionInoperative
The ligh tsensor is faulty.
XVisit aqualified specialist workshop .
b
Switch Off Lights
You leaveth evehicl eand th elights are switched on . Awarning tone
also sounds.
XTurn th eligh tswitch to th eà position .
b
Switch On Headlamps
You are drivin gwit hlow-beam headlamp sswitched off .
XTurn theligh tswitch to th eL orà position .
Display messages267
On-board computer and displays
Z

Engine
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system (for vehicles with gasoline engines)
Rin the fuel system
The emission limit values may be exceeded and the engine may be in emergency
mode.
XVisit a qualified specialist workshop immediately.
In some states, you must immediately visit a qualified specialist workshop as soon as the yellow Check Engine warning lamp lights up. This is due to the legal require-
ments in effect in these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.
8N The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
8N The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the ;Check Engine warning lamp may light up.
The fuel system pressure is too low. The fuel filler cap is not closed correctly or the
fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visit a qualified specialist workshop.
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the scale.
The temperature sensor for the coolant temperature gage is defective.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 177).
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster293
On-board computer and displays
Z