brake sensor MERCEDES-BENZ METRIS 2017 MY17 Operator’s Manual

into account road, weather or traffic conditions.
The distance warning function is only an aid. You
are responsible for the distance to the vehicle in
front, for vehicle speed, braking in good time
and for staying in your lane.
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.
If you change wheel size, make sure they corre- spond to the correct wheel size category
(
Ypage 277). If the category is changed without
recoding the control units in the vehicle, the
functioning of the distance warning feature may
be impaired. COLLISION PREVENTION ASSIST
may then detect a malfunction and switch itself
off.
Operation
XTo activate/deactivate: activate or deacti-
vate the distance warning function in the on-
board computer (
Ypage 185).
If the distance warning function of COLLISION
PREVENTION ASSIST is activated, the display
shows the Äsymbol:
Rin the header
Rin the Status Overviewof the Assist.menu (Ypage 184)
At speeds up to approx 20 mph (30 km/h) the
display in vehicles with Active Parking Assist
first shows the ístatus indicator. Only up to
a speed of about 20 mph (30 km/h) does the display show the Äsymbol instead of the
í status indicator.
The distance warning function can help you to
minimize the risk of a front-end collision with a
vehicle ahead or reduce the effects of such a
collision. With the help of the radar sensor sys-
tem, the distance warning function can detect
obstacles that are in the path of your vehicle for
an extended period of time. If the distance warn-
ing function detects that there is a risk of a col-
lision, you will be warned visually and, where
necessary, acoustically. Without your interven-
tion, the distance warning function cannot pre-
vent a collision.
The distance warning function issues a warning
at speeds:
Rfrom about 4 mph (7 km/h) if you approach a
vehicle traveling in front or a stationary vehi-
cle too quickly. The ·warning lamp in the instrument cluster then lights up and an inter-
mittent warning tone also sounds.
At speeds up to about 45 mph (70 km/h), the
system also detects stationary obstacles, for
example stopped or parked vehicles.
XBrake immediately until the distance from the
obstacle increases and the risk of a front-end
collision passes.
or
XTake evasive action, provided it is safe to do
so.
Adaptive Brake Assist
General notes
Adaptive Brake Assist evaluates the traffic sit-
uation with the help of the radar sensor system and can detect obstacles which have been in
your vehicle's path for an extended period of
time. From speeds above 4 mph (7 km/h), Adap-
tive Brake Assist aids you in braking during haz-
ardous situations.
Up to a speed of approximately 125 mph
(200 km/h), Adaptive Brake Assist is capable of
reacting to moving obstacles that have already
been detected as such at least once over the
period of observation.
Important safety notes
GWARNING
Adaptive Brake Assist does not react:
Rto people or animals
Rto oncoming vehicles
Rto crossing traffic
Rto stationary obstacles
Rwhen cornering
As a result, the Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
GWARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
Driving systems145
Driving and parking
Z

In such cases, Adaptive Brake Assist can:
Rintervene unnecessarily
Rnot intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
In particular, the detection of obstacles can be
impaired in the case of:
Rdirt on the sensors or anything else covering
the sensors
Rsnow or heavy rain
Rinterference from other radar sources
Rstrong radar reflections, for example, in park-
ing garages
Ra narrow vehicle traveling in front, e.g. a
motorbike
Ra vehicle traveling in front on a different line
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause Adaptive Brake Assist to inter-
vene.
If you fail to adapt your driving style, Adaptive
Brake Assist can neither reduce the risk of acci-
dent nor override the laws of physics. Adaptive
Brake Assist cannot take into account road,
weather or traffic conditions. Adaptive Brake
Assist is only an aid. You are responsible for the
distance to the vehicle in front, for vehicle
speed, braking in good time and for staying in
your lane.
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.
If you change wheel size, make sure they corre- spond to the correct wheel size category
(
Ypage 277). If the category is changed without
recoding the control units in the vehicle, the
functioning of Adaptive Brake Assist may be
impaired. COLLISION PREVENTION ASSIST may
then detect a malfunction and switch itself off.
If Adaptive Brake Assist is not available due to a
malfunction in the radar sensor system, the
brake system remains available with full brake
boosting effect and BAS.
Operation
With the help of the radar sensor system, Adap-
tive Brake Assist can detect obstacles that have been in the path of your vehicle for an extended
period of time. Ada

ptive Brake Assist does not
react to stationary obstacles. If Adaptive Brake
Assist detects a risk of collision with a vehicle
traveling in front or with a stationary obstacle,
the system calculates the braking force neces-
sary to avoid this collision. If you apply the
brakes forcefully, Adaptive Brake Assist will
automatically increase the braking force to a
level suitable for the traffic conditions.
XBrake until the distance to the obstacle
increases and the risk of a collision passes.
ABS prevents the wheels from locking.
The brakes function as usual again if:
Ryou release the brake pedal
Rthere is no longer any danger of a collision
Rno obstacle is detected in front of your vehicle
Braking assistance is then ended.
Blind Spot Assist
General notes
Blind Spot Assist monitors the areas on either
side of the vehicle that are not visible to the
driver with two lateral, rear-facing radar sensors
in the bumper. It supports you from speeds of
approximately 20 mph (30 km/h). A warning
display in the exterior mirrors draws your atten-
tion 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 collision warning.
Important safety notes
GWARNING
Blind Spot Assist does not react to:
Rvehicles overtaken too closely on the side,
placing them in the blind spot area
Rvehicles which approach with a large speed
differential and overtake your vehicle
As a result, Blind Spot Assist may not give
warnings in such situations. There is a risk of
an accident.
146Driving systems
Driving and parking

XSelectStatus Overviewin theAssist.menu and display the attention level
(Ypage 184).
The following information is displayed:
Rthe length of the journey since the last break.
Rthe attention level determined by ATTENTION
ASSIST, displayed in a bar display in five levels
from low to high.
Rif ATTENTION ASSIST is unable to calculate
the attention level and cannot output a warn-
ing, the System
Passivemessage appears in
the display. The bar display is then dimmed.
This is the case, for example, if you are pre-
dominantly driving at a speed below 40 mph
(60 km/h) or above 125 mph (200 km/h).
Activating ATTENTION ASSIST
XActivating ATTENTION ASSIST with the on-
board computer:
Ron vehicles without steering wheel buttons
(Ypage 175)
Ron vehicles with steering wheel buttons
(Ypage 185)
For vehicles with steering wheel buttons, the
system determines the attention level of the
driver depending on the setting selected:
Standard: the sensitivity with which the sys-
tem determines the attention level is set to
normal.
Sensitive: the sensitivity is set higher. The
driver is warned earlier.
When ATTENTION ASSIST is switched on and
the vehicle engine is running:
Ron vehicles without steering wheel buttons,
the À indicator lamp in the instrument
cluster lights up
Ron vehicles with steering-wheel buttons, the
display shows the Àsymbol:
-in the status area
-in the Status Overviewof the Assist.menu (Ypage 184)
For vehicles with steering wheel buttons, if you
deactivate ATTENTION ASSIST, the system is
automatically re-activated when you start the
engine. The system sensitivity then corresponds
to the last selection activated – standard or sen-
sitive.
If you switch off ATTENTION ASSIST in a vehicle without steering wheel buttons, the system
remains switched off even after you start the engine. The status of the system after switching
on the engine always corresponds to the status
last selected.
Warning in the display
If the system detects tiredness or increasing
lapses in concentration, the warning
Atten‐
tion Assist: Take a Break!orAttent.Asst: Take Break!is shown in the display.
An additional warning tone sounds.
XIf necessary, take a break.
XConfirm the message by pressing the a
button on the steering wheel.
On long journeys, take regular breaks in good
time to allow yourself to rest. If you do not take
a break and ATTENTION ASSIST continues to
detect increasing lapses in concentration, you
will be warned again after 15 minutes at the
earliest. This will only happen if ATTEN-
TION ASSIST still detects typical indicators of
fatigue or increasing lapses in concentration.
PARKTRONIC
General notes
PARKTRONIC is an electronic parking aid. The
system is equipped with ultrasonic sensors in
the front and rear bumpers to monitor the area
around your vehicle. PARKTRONIC indicates vis-
ually and audibly the distance between your
vehicle and an object.
Your vehicle features two separate sound emit- ters with different frequencies for the warning
tones. The warning ranges in front of and behind
the vehicle are indicated by different warning
tones.
PARKTRONIC is activated automatically when
you:
Rturn the key to position 2in the ignition lock
Rrelease the parking brake and
Rmove the selector lever to position D,N or R
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). PARKTRONIC is reactivated
at speeds below 10 mph (16 km/h).
Important safety notes
PARKTRONIC is only an aid. It cannot replace
your own awareness of the immediate surround-
ings. You are responsible for safe maneuvering,
Driving systems151
Driving and parking
Z

parking and pulling away. Make sure that there
are no persons, animals or objects in the maneu-
vering area while maneuvering and parking in/
leaving parking spaces.
!Pay particular attention to obstacles above
or below the sensors when parking, such as
flower pots or trailer towbars. PARKTRONIC
does not recognize such objects when they
are in the immediate vicinity of the vehicle.
You could damage the vehicle or objects.
PARKTRONIC can suffer interference from:
Rultrasonic sources such as a truck's
compressed-air brakes, an automatic car
wash or a pneumatic drill
Rattachments to the vehicle, e.g. rear moun-
ted racks
Rnumber plates (vehicle license plates) that
are not affixed flat against the bumper
Rdirty or icy sensors
Remove a detachable trailer coupling if it is no
longer required. PARKTRONIC measures the
minimum detection range to an obstacle from
the bumper, not the ball coupling.
Range of the sensors
PARKTRONIC does not account for obstacles
that are:
Rbeneath its detection range, e.g. persons, ani-
mals or objects
Rabove its detection range, e.g. overhanging
loads, overhangs or truck loading ramps
The sensors must be free of dirt, ice or slush.
Otherwise, they cannot function correctly.
Clean the sensors regularly, taking care not to
scratch or damage them (
Ypage 266).
Front sensors
CenterApprox. 39 in
(100 cm)
CornersApprox. 24 in (60 cm)
Rear sensors
CenterApprox. 47 in
(120 cm)
CornersApprox. 31 in (80 cm)
Minimum distance
CenterApprox. 8 in (20 cm)
CornersApprox. 8 in (20 cm)
If an obstacle is within this range, the corre-
sponding segments of the warning displays light
up and you hear a warning tone. If the distance
falls below the minimum, the distance from an
obstacle may no longer be shown.
152Driving systems
Driving and parking

Towing a trailer
PARKTRONIC detects a coupled trailer if your
vehicle is equipped with the corresponding elec-
trical installations for trailer towing.
PARKTRONIC is deactivated for the rear area
when you establish an electrical connectionbetween your vehicle and a trailer. If you use an
adapter for the socket, remove it from the
socket after detaching the trailer. Otherwise,
PARKTRONIC remains deactivated for the rear
area.
Problems with PARKTRONIC
ProblemPossible causes/consequences and
MSolutions
Only the red segments in
the PARKTRONIC warn-
ing displays are lit.
In addition, a warning
tone sounds for approx.
two seconds
PARKTRONIC is then
deactivated.
The indicator lamp of the
f button lights up
and the red segments in
the PARKTRONIC warn-
ing display go out.PARKTRONIC has malfunctioned and has switched itself off.
XIf problems persist, have PARKTRONIC checked at a qualified spe- cialist workshop.
The PARKTRONIC warn-
ing displays implausible
distances.
For example, all the seg-
ments may be lit even
though there is no obsta-
cle present.The PARKTRONIC sensors are dirty or iced up.
XClean the PARKTRONIC sensors (Ypage 266).
XTurn the key to position 2in the ignition lock.
The license plate or other parts attached near the sensors may not be
secured correctly.
XCheck the license plate and attachment parts near the sensors for
correct seating.
An external radio or ultrasonic source may be causing interference.
XCheck PARKTRONIC functions in a different location.
Active Parking Assist
General notes
Active Parking Assist is an electronic parking
aid. The system uses ultrasound sensors to
measure the road on both sides of the vehicle
and indicates suitable parking spaces. It can
then actively steer and brake the vehicle to help
you to park and exit the parking space.
Active Parking Assist includes the PARKTRONIC
parking aid which indicates visually and audibly the distance between your vehicle and an
object. To do this, PARKTRONIC uses the ultra- sonic sensors of the Active Parking Assist
(
Ypage 151).
Important safety notes
Active Parking Assist is only an aid. It is not a
substitute for your attention to the immediate
surroundings. You are responsible for safe
maneuvering, parking and pulling away. Make
sure that no persons, animals or objects are in
the maneuvering range.
When you deactivate PARKTRONIC, Active Park-
ing Assist will also be deactivated.
154Driving system
s
Driving an d parking

Lights
Display messagesPossible causes/consequences andMSolutions
b
CheckLeftLowBeamorCheck Right LowBeam
The left or right-hand low-beam headlamp is faulty.
XChange the bulb (Ypage 100).
b
Chk. Trailer L.Turn Sig.orChk.TrailerR.TurnSig.
The left or right-hand trailer turn signal lamp is faulty.
XChange the bulb (see the trailer manufacturer's operating instruc-
tions).
b
Chk. Trailer BrakeLamp
The trailer brake lamp is faulty.
XChange the bulb (see the trailer manufacturer's operating instruc-
tions).
b
Chk. Trailer L.Tail LamporChk.TrailerR.TailLamp
The left or right-hand trailer tail lamp is faulty.
XChange the bulb (see the trailer manufacturer's operating instruc-
tions).
b
Auto Lamps Inopera‐tive
The light sensor is faulty. The automatic headlamp feature is mal-
functioning.
XSwitch the light functions on/off manually (Ypage 94).
XVisit a qualified specialist workshop.
b
Chk. Rear L. TurnSignalorChk. RearR. Turn Signal
The rear left-hand or rear right-hand turn signal is faulty.
XChange the bulb (Ypage 100).
b
Chk. Front L. TurnSignalorChk.FrontR.TurnSignal
The front left-hand or front right-hand turn signal is faulty.
XChange the bulb (Ypage 100).
b
Chk. Center BrakeLamp
The high-mounted brake lamp is faulty.
XVisit a qualified specialist workshop.
b
Chk.L.Tail/BrakeLamporChk. R.Tail/ Brake Lamp
The left or right-hand tail lamp/brake lamp is faulty.
XChange the bulb (Ypage 100).
196Display messages (vehicles without steering wheel buttons)
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
b
CheckTrailerBrakeLamp
The trailer brak elamp is faulty.
XChange th ebulb (see th etrailer manufacturer' soperating instruc-
tions).
b
Check Traile rLef tTailLam porCheckTraile rRight Tai lLamp
The lef tor right-hand trailer tai llamp is faulty.
XChange th ebulb (see th etrailer manufacturer' soperating instruc-
tions).
b
Aut oLam pFunctionInoperative
The ligh tsensor is faulty. The automatic headlamp feature is mal-
functioning .
XSwitchth eligh tfunction son/off manually (Ypage 94).
XVisitaqualified specialist workshop .
b
Check RearLef tTurnSignalor
Check Rea rRight
Tur nSignal
The rear left-han dor rear right-hand tur nsignal is faulty.
XChange th ebulb (Ypage 100).
b
Check Front Lef tTurnSignalor
Check Front Right
Tur nSignal
The fron tleft-han dor fron tright-hand tur nsignal is faulty.
XChange th ebulb (Ypage 100).
b
Check Center BrakeLamp
The high-mounte dbrak elamp is faulty.
XVisit aqualified specialist workshop .
b
CheckLeftTailandBrake Lampsor
Check Right Tai l
and Brake Lamps
The leftor right-hand tai llamp/brake lamp is faulty.
XChange th ebulb (Ypage 100).
b
Check Lef tHig hBeamorCheck RightHig hBea m
The lef tor right-hand high-beam headlamp is faulty.
XChange th ebulb (Ypage 100).
b
Licens ePlate Lam p
The leftor right-hand license plat elamp is faulty.
XVisit aqualified specialist workshop .
210Display messages (vehicles withsteering whee lbu ttons)
On-board computer and displays

Tires
Display messagesPossible causes/consequences andMSolutions
AdjustTirePressureThe tire pressure is too low in at least one of the tires, or the tire
pressure difference between the wheels is too great.
XCheck the tire pressure at the next opportunity (Ypage 284).
XIf necessary, correct the tire pressure.
XRestart the tire pressure monitor (Ypage 287).
Check TiresAn additional warning tone sounds.
The tire pressure in one or more tires has dropped significantly. The
display shows the wheel position.
GWARNING
Underinflated tires pose the following risks:
RThe tires may burst, especially as the load and vehicle speed
increase.
RThe tires may wear excessively and/or unevenly, which may greatly
impair tire traction.
RThe handling as well as steering and braking characteristics may be
severely affected.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions while doing so.
XSecure the vehicle to prevent it from rolling away (Ypage 133).
XCheck the tires and, if necessary, change the wheel (Ypage 296).
XCheck the tire pressure (Ypage 284).
XIf necessary, correct the tire pressure.
Warning Tire Mal‐functionThe tire pressure in one or more tires has dropped suddenly. The dis-
play shows the wheel position.
GWARNING
Driving with a flat tire poses a risk of the following hazards:
RA flat tire affects the ability to steer or brake the vehicle.
RYou could then lose control of the vehicle.
RContinued driving with a flat tire will cause excessive heat build-up
and possibly a fire.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions while doing so.
XSecure the vehicle to prevent it from rolling away (Ypage 133).
XCheck the tires and, if necessary, change the wheel (Ypage 296).
Tire Pressure Moni‐tor CurrentlyUnavailable
Due to a source of radio interference, no signals can be received from
the wheel sensors. The tire pressure monitor is temporarily malfunc-
tioning.
The tire pressure monitor restarts automatically as soon as the prob-
lem has been solved.
Displa y messages (vehicles withsteering whee lbu ttons)217
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
Wheel Sensor(s)MissingThere is no signal from th etire pressur esensor of on eor several
wheels. The pressur eof th eaffecte dtire is no tshown in th edisplay.
XHav eth efault ytire pressur esensor replace dat aqualified special -
ist workshop .
TirePressure Moni‐tor Inoperative NoWheel Sensor s
The wheels installed do no thav esuitable tire pressur esensors. The
tire pressur emonitor is deactivated.
XInstall wheels wit hsuitable tire pressur esensors.
The tire pressur emonitor is activated automatically after drivin gfor
a few minutes.
Tir ePress.Monito rInoperativeThe tire pressur emonitor is malfunctioning .
XVisitaqualified specialist workshop .
Vehicle
Display messagesPossible causes/consequences and MSolutions
Shiftto'P'or'N'to Start EngineYou haveattempte dto start th eengin ewit hth etransmission in posi-
tion Ror D.
XShift th etransmission to position Por N.
Auxiliary Batter yMalfunctionThe auxiliary battery for th etransmission is no longer bein gcharged.
XVisit aqualified specialist workshop .
Apply Brake toShift from'P'You hav eattempte dto mov eth etransmission selector lever to posi-
tion D,Ror Nwithout depressing th ebrak epedal .
XDepress th ebrak epedal .
Riskof Rolling:TransmissionNotinP
An additional warning tone sounds. The driver's door is open and th e
transmission is in position R,N or D.
XShift th etransmission to position P.
XSecureth evehicl eto preven tit from rollin gaway (Ypage 133).
Servic eRequiredDoNot Shift GearsVisit Dealer
An additional warning tone sounds. You canno tchang eth etransmis -
sion position due to amalfunction .
If transmission position Dis selected:
XDrive to aqualified specialist workshop without shifting th etrans -
mission from position D.
If transmission position R,N or Pis selected:
XConsult aqualified specialist workshop .
OnlyShift to 'P'whe nVehicl eisSta‐tionar y
The vehicl eis still moving .
XPull overand stop th evehicle, payin gattention to roa dand traffic
conditions.
XShift th etransmission to position P.
218Display messages (vehicles withsteering whee lbu ttons)
On-board computer and displays

Exterior
Cleaning the wheels
!Do not use any acidic or alkaline cleaning
agents. They can cause corrosion on the
wheel bolts or the retainer springs for the
wheel-balancing weights.
!Do not park your vehicle for a long period of
time directly after cleaning, particularly after
cleaning the wheel rim with wheel cleaner.
Wheel cleaner can lead to the increased cor-
rosion of the brake discs and pads. Therefore,
drive for a few minutes after cleaning. By
heating up the brakes, the brake discs and
pads dry. The vehicle can then be parked for a
long period of time.
If you clean the wheels with a power washer,
observe the safety notes for the power washer
(
Ypage 264). You could otherwise damage the
tires.
Cleaning the wiper blades
GWARNING
You could become trapped by the windshield wipers if they start moving while cleaning the
windshield or wiper blades. There is a risk of
injury.
Always switch off the windshield wipers and
the ignition before cleaning the windshield or
wiper blades.
!Do not fold the windshield wipers away from
the windshield unless the hood is closed. Oth-
erwise, you could damage the hood.
!Do not pull the wiper blade. Otherwise, the
wiper blade could be damaged.
!Do not clean wiper blades too often and do
not rub them too hard. Otherwise, the graph-
ite coating could be damaged. This could
cause wiper noise.
!Hold the wiper arm securely when folding
back. The windshield could be damaged if the
wiper arm smacks against it suddenly.
XTurn the SmartKey to position 0in the ignition
lock or remove the SmartKey.
XFold the windshield wiper arms away from the
windshield until you feel them engage.
XCarefully clean the wiper blades with a damp
cloth.
XFold back the wiper arms before switching on
the ignition.
Cleaning the exterior lighting
!Only use cleaning agents or cleaning cloths
which are suitable for plastic light lenses.
Unsuitable cleaning agents or cleaning cloths
could scratch or damage the plastic light len- ses.
XClean the plastic covers of the exterior light-
ing with a damp sponge and a mild cleaning
agent, e.g. Mercedes-Benz car shampoo, or
with cleaning cloths.
Cleaning the sensors
!Do not use dry, coarse or hard cloths and do
not scrub. You will otherwise scratch or dam-
age the sensors.
If you clean the sensors with a power washer
or steam cleaner, observe the information
provided by the manufacturer regarding the
distance to be maintained between the vehi-
cle and the nozzle of the power washer.
XClean drive system sensors :with water, car
shampoo and a soft cloth.
266Care
Maintenance and care