2017 MERCEDES-BENZ S CLASS brake sensor

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
not give a warning or 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
if: R
there is poor visibility, e.g. due to insufficient
illumination of the road, or due to snow, rain,
fog or spray R
there is glare, e.g. from oncoming traffic, the
sun or reflection from other vehicles (e.g. if
the road surface is wet) R
the windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in the vicin-
ity 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
there are no, several or unclear lane markings
for a lane, e.g. in areas with road construction
work R
the lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow R
the distance to the veh icle in front is too small
and the lane markings thus cannot be detec-
ted R
the lane markings change quickly, e.g. lanes
branch off, cross one another or merge R
the road is narrow and winding R
there are strong shadows cast on the road
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 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 second s.
In orde r that you are warned only when neces-
sary and in good time if you cross the lane mark-
ing, the system recognizes certain conditions
and warns you accordingly.
The warning vibration occurs earlier if: R
you approach the outer lane marking on a
bend. R
the road has very wide lanes, e.g. a highway. R
the system recognizes solid lane markings.
The warning vibration occurs later if: R
the road has narrow lanes. R
you cut the corner on a bend.
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.
G WARNING
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.
G WARNING
Active Lane Keeping Assist does not detect
traffic conditions or road users. In very rare
cases, the system may make an inappropriate
brake application, e.g. after intentionally driv-
ing over a solid lane marking. There is a risk of
an accident.
An inappropriate brake application may be
interrupted at any time if you steer slightly in
the opposite direction. Always make sure that
there is sufficient distance on the side for
other traffic or obstacles.Driving systems 207
Driving and parking Z

Display messages
Possible causes/consequences and P Solutions
The yellow $ warning lamp lights up and th e red I (US A only)
or $ (Canada only) indicator lamp flashes .
It is no t possibl e to apply th e electric parking brak e manually.X
Shift th e transmission to position P .X
Visit a qualified specialist workshop .
' (USA
only)
M ( Canada
only)
Check Brake Fluid
Level There is no t enough brak e flui d in th e brak e fluid reservoir .
In addition , th e ' (US A only) or M (Canada only) warning lamp
lights up in th e instrumen t cluste r and a warning tone sounds.
G WARNIN G
The braking effec t may be impaired.
There is a ris k of an accident.X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions. Do no t continu e drivin g
under any circumstances. X
Secur e th e vehicl e against rollin g away ( Y
page 162).X
Consult a qualified specialist workshop .X
Do no t add brak e fluid . This does no t correc t th e malfunction .
& Check Brake Pad Wea r The brak e pads/linings hav e reached their wear limit.
US A only: th e red ' brak e system warning lamp also lights up while
th e engin e is running. X
Visit a qualified specialist workshop .
S Inoperative On e or mor e main features of th e mbrace system are malfunctioning .X
Visit a qualified specialist workshop .
Collision Preven ‐
tio n Assist Plu s
Currently Unavaila‐
ble See Operator' s
Manual COLLISION PREVENTION ASSIST PLU S is temporarily no t operational.
Possibl e causes are: R
th e radar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiationR
th e system is outside th e operating temperature rangeR
th e on-boar d voltag e is to o low.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
COLLISION PREVENTION ASSIST PLU S is operational again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 162).X
Restart th e engine. Display messages 23 3
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
Collision Preven ‐
tio n Assist Plu s
Inoperative COLLISION PREVENTION ASSIST PLU S is temporarily inoperative due
to a malfunction . Adaptive Brake Assis t may also hav e failed.X
Visit a qualified specialist workshop immediately.
PRE-SAFE Inopera‐
tiv e See Operator' s
Manual Importan t function s of PRE-SAF E ®
hav e failed. Al l other occupant
safet y systems , e.g. air bags , remain available.X
Visit a qualified specialist workshop immediately.
PRE-SAFE Functions
Currently Limite d
See Operator' s Man ‐
ual PRE ‑ S AF E ®
PLU S or PRE ‑ SAFE ®
Brake is temporarily inoperative.
Possibl e causes are: R
function is impaire d due to heav y rain or snowR
th e radar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiationR
th e system is outside th e operating temperature rangeR
th e on-boar d voltag e is to o low.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
PRE ‑ S AF E ®
PLU S and PRE ‑ S AF E ®
Brake are operational again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 162).X
Restart th e engine.
PRE-SAFE Functions
Limite d See Opera‐
tor's Manual PRE ‑ S AF E ®
PLU S or PRE ‑ SAFE ®
Brake is unavailable due to a mal-
function . BA S PLU S wit h Cross-Traffic Assis t may also hav e failed.X
Visit a qualified specialist workshop immediately.234
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
Radar Sensor s Dirty
See Operator' s Man ‐
ual The radar sensor system is malfunctioning .
Possibl e causes are: R
Dirt on sensor sR
Heavy rain or snow R
Whe n drivin g on inter-urban roads without traffic or infrastructure,
e.g. in desert-like area s
At least on e drivin g system or drivin g safet y system is malfunctioning
or is temporarily unavailable :R
PRE-SAF E ®
PLU SR
PRE-SAF E ®
BrakeR
COLLISION PREVENTION ASSIST PLU SR
Active Lan e Keepin g Assis tR
Active Blind Spot Assis tR
DISTRONI C PLU S wit h Steering Assis t and Stop&Go Pilo t
If th e radar sensor system in fron t is dirty, Active Blind Spot Assis t will
no t perfor m a course-correcting brak e application .
A warning tone also sounds.
Once th e caus e of th e problem is no longer present, th e drivin g and
drive safet y systems will be available again . The display message dis-
appears.
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 162).X
Switc h off th e engine.X
Clean all sensor s ( Y
page 323).X
Restart th e engine.
The display message disappears.
Check Lef t Rea r
Bel t See Operator' s
Manual or Check
Right Rea r Bel t See
Operator' s Manual The seat belt buckl e extender on th e right or lef t of th e rear compart-
men t is no t in th e predefine d position . The belt strap may be jammed
in th e belt tongue.
G WARNIN G
If th e seat belt buckl e extender is no t in th e predefine d position , th e
seat belt canno t provid e th e intended level of protection .
There is an increased ris k of injury.X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Releas e th e jamming.X
Repeat th e seat belt fastenin g procedure .Display messages 23 5
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
Tir e Pressure Moni‐
tor Inoperative No
Wheel Sensor s The wheels mounte d do no t hav e a suitable tire pressur e sensor . The
tire pressur e monitor is deactivated.X
Moun t wheels wit h suitable tire pressur e sensors.
The tire pressur e monitor is activated automatically after drivin g for
a few minutes.
Tir e Press. Monito r
Inoperative The tire pressur e monitor is faulty.X
Visit a qualified specialist workshop .
Vehicle Display messages
Possible causes/consequences and P Solutions
Shift to 'P' or 'N'
to Start Engine You hav e attempte d to start th e engin e wit h th e transmission in posi-
tion R or D . X
Shift th e transmission to position P or N .
Apply Brake to
Shift fro m 'P' You hav e attempte d to mov e th e transmission selector lever to posi-
tion D , R or N without depressing th e brak e pedal .X
Depress th e brak e pedal .
To Deselect P or N,
Depres s Brake and
Start Engine Wit h th e engin e switched off , you hav e attempte d to shift th e trans -
mission out of position P or N int o another transmission position .X
Depress th e brak e pedal .X
Start th e engine.
Transmission Not in
P Ris k of Vehicl e
Rollin g Awa y The driver's door is open or no t full y closed and th e transmission is in
position R , N or D .
A warning tone also sounds.
G WARNIN G
The vehicl e may rol l away.
There is a ris k of an accident.X
Shift th e transmission to position P .X
Secur e th e vehicl e against rollin g away ( Y
page 162).X
Clos e th e driver's door completely.
Onl y Shift to 'P'
whe n Vehicl e is Sta ‐
tionar y The vehicl e is moving .X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Shift th e transmission to position P .254
Display messages
On-board computer and displays