brake sensor MERCEDES-BENZ GLC 2017 User Guide

DISTRONI C PLUS
General notes DISTRONIC PLU S regulates th e speed and auto-
matically helps you maintain th e distanc e from
th e vehicle detecte d in front. Vehicles are detec -
te d wit h th e aid of th e radar sensor system.
DISTRONIC PLU S brake s automatically so that
th e set speed is no t exceeded.
Change into a lowe r gear in goo d time on lon g
and steep downhill gradients. Thi s is especially
important if th e vehicle is laden. By doin g so, you
will mak e use of th e braking effect of th e engine.
Thi s relieves th e load on th e brake syste m and
prevents th e brake s from overheatin g and wear -
in g to o quickly.
If DISTRONIC PLU S detects that there is a ris k of
a collision , you will be warned visually and
acoustically. DISTRONIC PLU S canno t preven t a
collision without your intervention . An intermit -
tent warnin g tone will then soun d and th e dis -
tanc e warnin g lamp will ligh t up in th e instru-
men t cluster. Brak e immediately in order to
increase th e distanc e to th e vehicle in fron t or
take evasiv e action provided it is saf e to do so.
DISTRONIC PLU S operates in th e speed range
between 0 mph (0 km/ h) an d 120 mph
(200 km/h).
Do not use DISTRONIC PLUS whil e driving on
roa ds with steep gradients.
As DISTRONIC PLUS transmits radar waves, it
can resemble the radar detectors of the respon-
sible authorities. You can refer to the relevant
chapter in the Operator's Manual if questions
are asked about this.
i USA only: This device has been approved by
the FCC as a "Vehicular Radar System". The
radar sensor is intended for use in an auto-
motive radar system only. Removal, tamper-
ing, or altering of the device will void any war-
ranties, and is not permitted by the FCC. Do
not tamper with, alter, or use in any non-
approved way.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
i Canada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause interference,
and 2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the device
will void any warranties, and is not permitted.
Do not tamper with, alter, or use in any non-
approved way.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
Important safety notes
G WARNING
DISTRONIC PLUS does not react to: R
people or animals R
stationary obstacles on the road, e.g. stop-
ped or parked vehicles R
oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
G WARNING
DISTRONIC PLUS cannot always clearly iden-
tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may: R
give an unnecessary warning and then
brake the vehicle R
neither give a warning nor intervene R
accelerate or brake unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS.
G WARNING
DISTRONIC PLUS brakes your vehicle with up
to 50% of the maximum possible deceleration.
If this braking force is insufficient, DISTRONIC
PLUS warns you visually and audibly. There is
a risk of an accident.164
Driving systems
Driving and parking

In such cases, apply the brakes yourself and
try to take evasive action.
! When DISTRONIC PLUS or the HOLD func-
tion is activated, the vehicle brakes automat-
ically in certain situations.
To avoid damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or similar situations: R
when towing the vehicle R
in the car wash
DISTRONIC PLUS can neither reduce the risk of
an accident if you fail to adapt your driving style
nor override the laws of physics. DISTRONIC
PLUS cannot take account of road, weather and
traffic conditions. DISTRONIC PLUS is only an
aid. You are responsible for maintaining a safe
distance to the vehicle in front, for vehicle
speed, for braking in good time and for staying in
lane.
Do not use DISTRONIC PLUS: R
in road and traffic conditions which do not
allow you to maintain a constant speed, e.g. in
heavy traffic or on winding roads R
on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid R
in poor visibility, e.g. due to fog, heavy rain or
snow
DISTRONIC PLUS may not detect narrow vehi-
cles driving in front, e.g. motorcycles, or vehi-
cles driving on a different line.
In particular, the detection of obstacles can be
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is snow or heavy rain R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garages
If DISTRONIC PLUS no longer detects a vehicle
in front, DISTRONIC PLUS may unexpectedly
accelerate the vehicle to the stored speed. This speed may: R
be too high if you are driving in a filter lane or
an exit lane R
be so high in the right lane that you pass vehi-
cles driving on the left (left-hand drive coun-
tries) R
be so high in the left lane that you pass vehi-
cles driving on the right (in countries where
they drive on the left)
If there is a change of drivers, advise the new
driver of the speed stored.
Cruise control lever
C
Activates or increases speed D
Activates or reduces speed

PARKTRONIC is only an aid. It is not a replace-
ment for your attention to your immediate sur-
roundings. You are always responsible for safe
maneuvering, parking and exiting a parking
space. Make sure that there are no persons,
animals or objects in the maneuvering area
while maneuvering and parking in/leaving park-
ing spaces.
! When parking, pay particular attention to
objects above or below the sensors, such as
flower pots or trailer drawbars. PARKTRONIC
does not detect such objects when they are in
the immediate vicinity of the vehicle. You
could damage the vehicle or the objects.
The sensors may not detect snow and other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic car
wash, the compressed-air brakes on a truck
or a pneumatic drill could cause PARKTRONIC
to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
! Remove the detachable ball coupling if the
trailer tow hitch is not required. PARKTRONIC
measures the minimum detection range to an
obstacle from the bumper, not the ball cou-
pling.
PARKTRONIC is activated automatically when
you: R
switch on the ignition R
shift the transmission to position [ , ^ or
\\
PARKTRONIC is deactivated at speeds above
11 mph (18 km/ h) . It is reactivated at lower
speeds.
PARKTRONIC is deactivated for the rear area
when you establish an electrical connection
between your vehicle and a trailer.
Range of the sensors PARKTRONIC does not take objects into con-
sideration that are: R
below the detection range, e.g. people, ani-
mals or objects. R
above the detection range, for example over-
hanging loads, truck overhangs or loading
ramps. C
Sensors in the front bumper, left-hand side
(example)
C
Approx. 24 in (approx. 60 cm) (corners) D
Approx. 32 in (approx. 80 cm) (corners)

Problems with PARKTRONIC Problem
Possible causes/consequences and P Solutions
Only the red segments in
the PARKTRONIC warn-
ing displays are lit. You
also hear a warning tone
for approximately two
seconds.
PARKTRONIC is then
deactivated and the indi-
cator lamp on the
PARKTRONIC button
lights up. PARKTRONIC has malfunctioned and has switched off. X
If problems persist, have PARKTRONIC checked at a qualified spe-
cialist workshop.
Only the red segments in
the PARKTRONIC warn-
ing displays are lit.
PARKTRONIC is then
deactivated. The PARKTRONIC sensors are dirty or there is interference. X
Clean the PARKTRONIC sensors ( Y
page 315).X
Switch the ignition back on.
The problem may be caused by an external source of radio or ultra-
sound waves. X
See if PARKTRONIC functions in a different location.
Active Parking Assist
General notes Active Parking Assist is an electronic parking aid
with ultrasound. It measures the road on both
sides of the vehicle. A parking symbol indicates
a suitable parking space. Active steering inter-
vention and brake application can assist you
during parking and when exiting a parking
space. You may also use PARKTRONIC
( Y
page 175).
Important safety notes Active Parking Assist is merely an aid. It is not a
replacement for your attention to your immedi-
ate surroundings. You are always responsible
for safe maneuvering, parking and exiting a
parking space. Make sure that no persons, ani-
mals or objects are in the maneuvering range.
When PARKTRONIC is switched off, Active Park-
ing Assist is also unavailable.
For vehicles with a trailer tow hitch installed, the
minimum length for parking spaces is slightly
longer.
If you have attached a trailer to your vehicle, you
should not use Active Parking Assist. Once the
electrical connection is established between your vehicle and the trailer, Active Parking
Assist is no longer available. PARKTRONIC is
deactivated for the rear area.
G WARNING
While parking or pulling out of a parking
space, the vehicle swings out and can drive
onto areas of the oncoming lane. This could
result in a collision with another road user.
There is a risk of an accident.
Pay attention to other road users. Stop the
vehicle if necessary or cancel the Active Park-
ing Assist parking procedure.
! If unavoidable, you should drive over obsta-
cles such as curbs slowly and not at a sharp
angle. Otherwise, you may damage the
wheels or tires.
Active Parking Assist may possibly indicate
parking spaces which are not suitable for park-
ing, for example: R
where parking or stopping is prohibited R
in front of driveways or entrances and exits R
on unsuitable surfaces178
Driving systems
Driving and parking

When Standard is selected, no warning vibra-
tion occurs if: R
you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time. R
a driving safety system intervenes, e.g. ABS,
BAS or ESP ®
.
Adaptive
When Adaptive is selected, no warning vibra-
tion occurs if: R
you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time. R
a driving safety system intervenes, e.g. ABS,
BAS or ESP ®
.R
you accelerate hard, e.g. kickdown. R
you brake hard. R
you steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly. R
you cut the corner on a sharp bend.
In order 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 detects solid lane markings.
The warning vibration occurs later if: R
the road has narrow lanes. R
you cut the corner on a bend.
Driving Assistance PLUS package
General notes The Driving Assistance PLUS package consists
of DISTRONIC PLUS ( Y
page 164), Active Blind
Spot Assist ( Y
page 197) and Active Lane Keep-
ing Assist ( Y
page 200).
Active Blind Spot Assist
General notes
Active Blind Spot Assist uses a radar sensor
system, pointed toward the rear of the vehicle,
to monitor the area to the sides of the vehicle
which the driver is unable to see. A warning lamp lights up in the exterior mirrors and draws your
attention to vehicles detected in the monitored
area. If you then switch on the corresponding
turn signal to change lane, you will also receive
an optical and audible warning. If a risk of lateral
collision is detected, corrective braking may
help you avoid a collision. Before a course-cor-
recting brake application, Active Blind Spot
Assist evaluates the space in the direction of
travel and at the sides of the vehicle. For this,
Active Blind Spot Assist uses the forward-facing
radar sensors.
Active Blind Spot Assist supports you from a
speed of approximately 20 mph (30 km/h).
Important safety notes Active Blind Spot Assist is only an aid and is not
a substitute for attentive driving.
G WARNING
Active Blind Spot Assist does not react to: R
vehicles overtaken too closely on the side,
placing them in the blind spot area R
vehicles which approach with a large speed
differential and overtake your vehicle
As a result, Active Blind Spot Assist may nei-
ther give warnings nor intervene in such sit-
uations. There is a risk of an accident.
Always observe the traffic conditions care-
fully, and maintain a safe lateral distance.
i USA only: This device has been approved by
the FCC as a "Vehicular Radar System". The
radar sensor is intended for use in an auto-
motive radar system only. Removal, tamper-
ing, or altering of the device will void any war-
ranties, and is not permitted by the FCC. Do
not tamper with, alter, or use in any non-
approved way.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
i Canada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause interference,
and
2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.Driving systems 197
Driving and parking Z

Active Lane Keeping Assist Genera l notes
Active Lan e Keepin g Assis t monitors th e area in
fron t of your vehicl e by mean s of multifunction
camera C at th e to p of th e windshield. Various
differen t areas to th e front, rear and side of your
vehicl e are also monitore d wit h th e aid of th e
radar sensor system. Active Lan e Keepin g
Assis t detects lan e marking s on th e road and
can warn you before you leav e your lan e unin-
tentionally. If you do no t reac t to th e warning , a
lane-correcting application of th e brakes can
bring th e vehicl e bac k int o th e original lane.
This function is available in th e range between
40 mph and 12 0 mph (60 km/h and 20 0 km/h).
Important safety notes If you fail to adapt your drivin g style, Active Lan e
Keepin g Assis t can neither reduce th e ris k of an
acciden t no r override th e laws of physics . Active
Lan e Keepin g Assis t canno t tak e accoun t of
road and weather conditions. It may no t recog-
niz e traffic situations. Active Lan e Keepin g
Assis t is only an aid. You are responsibl e for th e
distanc e to th e vehicl e in front, for vehicl e
speed, for braking in goo d time and for stayin g in
your lane.
Active Lan e Keepin g Assis t canno t continuously
keep your vehicl e in it s lane.
G WARNIN G
Active Lan e Keepin g Assis t canno t always
clearly detec t lan e markings. In suc h cases, Active Lan e Keepin g Assis t
can : R
giv e an unnecessary warning and then
mak e a course-correcting brak e application
to th e vehicl e R
no t giv e a warning or interven e
There is a ris k of an accident.
Always pay particular attention to th e traffic
situation and keep within th e lane, especially
if Active Lan e Keepin g Assis t alerts you. Ter -
minate th e intervention in a non-critical driv-
ing situation .
The system may be impaire d or may no t function
if: R
there is poor visibility, e.g. due to insufficien t
illumination of th e road , or due to snow, rain ,
fog or spray R
there is glare, e.g. from oncomin g traffic, th e
sun or reflection from other vehicles (e.g. if
th e road surfac e is wet )R
th e windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in th e vicin-
it y of th e camera R
th e radar sensor s in th e fron t or rear bumpers
or th e radiato r trim are dirty, e.g. obscured by
snow R
there are no , several or unclear lan e marking s
for a lane, e.g. in areas wit h road construction
wor k R
th e lan e marking s are wor n away, dark or cov-
ere d up, e.g. by dir t or snowR
th e distanc e to th e vehicl e in fron t is to o small
a nd th e lan e marking s thus canno t be detec -
te d R
th e lan e marking s chang e quickly, e.g. lanes
branch off , cross on e another or mergeR
th e road is narrow and windin gR
there are highly variable shad e condition s on
th e roadway
If no vehicl e is detecte d in th e adjacent lan e and
broke n lan e marking s are detected, no lane-cor-
recting brak e application is made .
Warning vibration in th e steering wheel
A warning may be given if a fron t whee l passes
ove r a lan e marking . It will warn you by mean s of
intermittent vibration in th e steering whee l for
up to 1. 5 seconds.200
Driving systems
Driving and parking

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 ] .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 154).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 is lit 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 154).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 lowR
Mercedes-AMG vehicles: ES P ®
is deactivated
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
PRE ‑ SAFE ®
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 154).X
Restart th e engine.X
Mercedes-AMG vehicles: switch ES P ®
on again ( Y
page 71).
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 .
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 154).X
Switc h off th e engine.X
Clean all sensor s ( Y
page 315).X
Restart th e engine.
The display message disappears.
u SRS Malfunction Ser ‐
vic e Required The restrain t system is malfunctioning . The u warning lamp also
lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately.
Fo r further information about th e restrain t system, see ( Y
page 43) .
u Front Lef t Malfunc‐
tio n Servic e
Required or Front
Right Malfunction
Servic e Required The restrain t system is malfunctioning at th e fron t on th e lef t or right .
The u warning lamp also lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately. 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 ^ or [ .X
Shift th e transmission to position ] or \\ .
Apply Brake to
Shift fro m 'P' You hav e attempte d to shift th e transmission to position [ , ^ or \\
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 ] or \\ 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 ^ , \\ or [ .
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 ] .X
Secur e th e vehicl e against rollin g away ( Y
page 154).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 ] .252
Display messages
On-board computer and displays