2020 MERCEDES-BENZ METRIS light

may also cause the system to display a warn-
ing.
If you fail to adapt your driving style, the dis-
tance warning function can neither reduce the
risk of an accident nor override the laws of
physics. The distance warning function cannot
take into account road, weather or traffic con-
ditions. 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 vehi-
cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to collisions
at slow speeds where there is no visible dam-
age to the front of the vehicle.
If you change wheel size, make sure they cor-
respond to the correct wheel size category
(Y page
278). If the category is changed with-
out 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
X To activate/deactivate: activate or deacti-
vate the distance warning function in the on-
board computer

(Y page 190).
If the distance warning function of COLLI-
SION PREVENTION ASSIST is activated, the
display shows the Ä symbol:
R in the header
R in the Status Overview of the Assist.
menu (Y page 189)
At speeds up to approx 20 mph (30 km/h)
the display in vehicles with Active Parking
Assist first shows the í status indicator.
Only from a speed of about 20 mph
(30 km/h) does the display show the
Äsymbol instead of the í status indica-
tor.
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
warning function detects that there is a risk of
a collision, you will be warned visually and,
where necessary, acoustically. Without your intervention, the distance warning function
cannot prevent a collision.
The distance warning function issues a warn-
ing at speeds:
R from about

4 mph (7 km/h) if you approach
a vehicle traveling in front or a stationary
vehicle too quickly. The · warning lamp
in the instrument cluster then lights up and
an intermittent warning tone also sounds.
At speeds up to about 45 mph (70 km/h),
the system also detects stationary obsta-
cles, for example stopped or parked vehi-
cles.
X Brake immediately until the distance from
the obstacle increases and the risk of a
front-end collision passes.
or X Take 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 sys-
tem 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

),
Adaptive Brake Assist aids you in braking dur-
ing hazardous 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 G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R to stationary obstacles
R when cornering
As a result, the Adaptive Brake Assist may
not intervene in all critical conditions. There
is a risk of an accident. 150
Driving systems
Driving and parking

Warning display
Blind Spot Assist is not active 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 monitoring
range of Blind Spot Assist at speeds above
approximately 20 mph (30 km/h), warning
lamp : lights up red in the exterior mirror on
the corresponding side. Warning lamp :
always lights up 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 (11 km/h).
If you select reverse gear, Blind Spot Assist is
inactive.
The intensity of warning lamps : depends on
the brightness of the ambient light and is con-
trolled automatically.
Collision warning If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the cor-
responding turn signal, a double warning tone
sounds once. The warning lamp in the corre-
sponding exterior mirror flashes. If the turn
signal remains on, detected vehicles are indi-
cated by the flashing of the warning lamp in
the exterior mirror. There are no further warn-
ing tones.
Activating Blind Spot Assist X
Make sure that Blind Spot Assist is activa-
ted in the on-board computer (Y page

191).
X Turn the key to position 2 in the ignition
lock.
The warning lamps in the exterior mirrors
light up for approximately

1.5 seconds. Status indicators in the status overview submenu
If Blind Spot Assist is activated, the display
shows symbol : in the Status Overview
submenu of the on-board computer
(Y page

189). If you are driving faster than
20 mph (30 km/h), the symbol also shows
radar waves ; between the two vehicles.
Blind Spot Assist is then ready for use.
Towing a trailer If you attach a trailer, make sure that you have
correctly established the electrical connection.
This can be accomplished by checking the
trailer lighting. Blind Spot Assist is then deacti-
vated and the Blind Spot Assist Cur‐
rently Unavail. See Operator's Manual
message appears in the display. Lane Keeping Assist
General notes Lane Keeping Assist monitors the area in front
of your vehicle by means of camera : which
is mounted at the top of the windshield. Lane
Keeping Assist detects lane markings on the
road and can warn you before you leave your
lane unintentionally.
This function is available in the range between
40 mph (60 km/h

) and 125 mph (200 km/h).
A warning may be given if a front wheel
touches a lane marking. It will warn you by Driving systems
153
Driving and parking Z

means of intermittent vibration through the
steering wheel for up to
1.5 seconds.
Important safety notes G
WARNING
Lane Keeping Assist cannot always clearly
detect lane markings.
In such cases, Lane Keeping Assist can:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, espe-
cially if Lane Keeping Assist alerts you. G
WARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There
is a risk of an accident.
You should always steer, brake or accelerate
yourself, in particular if warned by Lane
Keeping Assist.
If you fail to adapt your driving style, Lane
Keeping Assist can neither reduce the risk of
accident nor override the laws of physics.
Lane Keeping Assist cannot take into account
road, weather or traffic conditions. Lane Keep-
ing 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.
Lane Keeping Assist does not keep your vehi-
cle in its lane.
The system may be impaired or may not func-
tion if:
R there is poor visibility, e.g. due to insuffi-
cient 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
vicinity of the camera
R there are no lane markings, or several
unclear lane markings for one lane, e.g.
around construction sites R
the lane markings are worn away, dark or
covered up, e.g. by dirt or snow
R the distance to the vehicle in front is too
short and thus 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 narrow and winding
R there are highly variable shade conditions
on the road
Deactivating and activating Lane Keep-
ing Assist X
Press the Ç button.
If the indicator lamp in the button lights up
and the display shows the Ç symbol in
the status area, Lane Keeping Assist is
switched on but not ready for use.
If you are driving with Lane Keeping Assist
activated at speeds above

40 mph
(60 km/h) and lane markings are detected,
the display shows the Ç symbol highligh-
ted in the status area. Lane Keeping Assist
is then ready for use. Status indicators in the status overview submenu
The display in the Status Overview submenu
of the on-board computer also shows the sta-
tus of Lane Keeping Assist

(Y page 189). If
Lane Keeping Assist is activated but not ready
for use, the display shows the lane markings in
the symbol as broken lines :. If Lane Keeping154
Driving systems
Driving and parking

For vehicles with steering wheel buttons you
can have the current ATTENTION ASSIST
(Attention Level) assessment displayed.
X Select Status Overview in the Assist.
menu and display the attention level
(Y page
189).
The following information is displayed: R the length of the journey since the last
break.
R the attention level determined by ATTEN-
TION ASSIST, displayed in a bar display in
five levels from low to high.
R if ATTENTION ASSIST is unable to calculate
the attention level and cannot output a
warning, the System Passive message
appears in the display. The bar display is
then dimmed. This is the case, for example,
if you are predominantly driving at a speed
below

40 mph (60 km/h) or above 125 mph
(200 km/h).
Activating ATTENTION ASSIST X
Activating ATTENTION ASSIST with the on-
board computer:
R on vehicles without steering wheel but-
tons

(Y page 180)
R on vehicles with steering wheel buttons
(Y page 190)
For vehicles with steering wheel buttons,
the system determines the attention level of
the driver depending on the setting selec-
ted:
Standard: the sensitivity with which the
system 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: R on vehicles without steering wheel buttons,
the À indicator lamp in the instrument
cluster lights up
R on vehicles with steering-wheel buttons, the
display shows the À symbol:
- in the status area
- in the Status Overview of the Assist.
menu (Y page

189)
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 corre-
sponds to the last selection activated – stand-
ard or sensitive.
If you switch off ATTENTION ASSIST in a vehi-
cle without steering wheel buttons, the system
remains switched off even after you start the
engine. The status of the system after switch-
ing 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! or Attent.
Asst: Take Break!is shown in the display.
An additional warning tone sounds.
X If necessary, take a break.
X Confirm 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 contin-
ues to detect increasing lapses in concentra-
tion, 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
visually and audibly the distance between your
vehicle and an object.
Your vehicle features two separate sound
emitters with different frequencies for the
warning tones. The warning ranges in front of
and behind the vehicle are indicated by differ-
ent warning tones.
PARKTRONIC is activated automatically when
you:
R turn the key to position 2 in the ignition lock
R release the parking brake and
R move the selector lever to position D, N or R156
Driving systems
Driving and parking

PARKTRONIC is deactivated at speeds above
11 mph (18 km/h
). PARKTRONIC is reactiva-
ted 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 sur-
roundings. You are responsible for safe
maneuvering, parking and pulling away. Make
sure that there are no persons, animals or
objects in the maneuvering area while maneu-
vering 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:
R ultrasonic sources such as a truck's
compressed-air brakes, an automatic car
wash or a pneumatic drill
R attachments to the vehicle, e.g. rear
mounted racks
R number plates (vehicle license plates)
that are not affixed flat against the
bumper
R dirty 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:
R beneath its detection range, e.g. persons,
animals or objects
R above its detection range, e.g. overhanging
loads, overhangs or loading ramps of trucks 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 (Y page

267).
Front sensors Center Approx. 39 in
(100 cm

) Corners Approx. 24 in
(60 cm

) Rear sensors
Center Approx. 47 in
(120 cm

) Corners Approx. 31 in
(80 cm

) Minimum distance
Center Approx. 8 in (20 cm)
Corners Approx. 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 dis- Driving systems
157
Driving and parking Z

tance from an obstacle may no longer be
shown.
Warning displays Front area warning display in center of dashboard
Rear area warning display on the dashboard
Rear area warning display in center of the head-
liner in the rear compartment.
:
Warning segments for the left side of the
vehicle
; Warning segments for the right side of the
vehicle
= Segments showing operational readiness
The warning displays show the distance
between the sensor and the obstacle. The warning display is divided into five yellow
and two red segments for each side of the
vehicle. PARKTRONIC is operational if opera-
tional readiness indicator = lights up.
There is a malfunction if only the red segments
of the warning display light up
(Y page 159).
The selected transmission position determines
whether the front and/or rear area is moni-
tored. Selector lever posi-
tion Monitoring
h
Front area
k or i Front and rear area
j
No areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle. In addi-
tion, warning tones are emitted.
When the distance to the obstacle is sufficient,
you will hear an intermittent warning tone.
When the distance to the obstacle is sufficient,
you will hear an intermittent warning tone.
When the minimum distance is reached, you
hear a continuous warning tone.
Roll-back warning Regardless of transmission position,
PARKTRONIC automatically monitors the area
behind the vehicle if the vehicle begins to roll
backwards, e.g. after stopping on an uphill gra-
dient.
Activating/deactivating PARKTRONIC X
Press the f button.
If PARKTRONIC is deactivated, the indicator
lamp in the switch lights up.158
Driving systems
Driving and parking

Towing a trailer
PARKTRONIC detects a coupled trailer if your
vehicle is equipped with the corresponding
electrical installations for trailer towing.
PARKTRONIC is deactivated for the rear area
when you establish an electrical connection
between 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 Problem
Possible causes/consequences and
M SolutionsOnly the red segments
in the PARKTRONIC
warning 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 seg-
ments in the
PARKTRONIC warning
display go out. PARKTRONIC has malfunctioned and has switched itself off.
X
If problems persist, have PARKTRONIC checked at a qualified
specialist workshop. The PARKTRONIC warn-
ing displays implausible
distances.
For example, all the
segments may be lit
even though there is no
obstacle present. The PARKTRONIC sensors are dirty or iced up.
X Clean the PARKTRONIC sensors ( Y page 267).
X Turn the key to position 2 in the ignition lock. The license plate or other parts attached near the sensors may not
be secured correctly.
X Check the license plate and attachment parts near the sensors
for correct seating. An external radio or ultrasonic source may be causing interference.
X Check 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 visu-
ally and audibly the distance between your vehicle and an obstruction. To do this,
PARKTRONIC uses the ultrasonic sensors of
the Active Parking Assist

(Y page 156).
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. Driving systems
159
Driving and parking Z

When you deactivate PARKTRONIC, Active
Parking Assist will also be deactivated.
For vehicles with a trailer coupling installed,
the minimum length for parking spaces will be
slightly increased.
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 then 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
Parking Assist parking procedure.
! If they cannot be avoided, drive over
obstacles such as curbs slowly and at an
obtuse angle. Otherwise, you may damage
the wheels or tires.
Active Parking Assist may also display spaces
not suitable for parking, e.g.:
R in a zone where parking or stopping is pro-
hibited
R in front of driveways or entrances and exits
R on unsuitable surfaces
Parking tips:
R on narrow roads, drive as closely as possible
past the parking space.
R parking spaces that are littered or over-
grown might be identified or measured
incorrectly.
R parking spaces that are partially occupied
by trailer drawbars might not be identified
as such or be measured incorrectly.
R snowfall or heavy rain may lead to a parking
space being measured inaccurately.
R when transporting a load which protrudes
from your vehicle, you should not use Active
Parking Assist.
R never use Active Parking Assist when snow
chains are installed. R
always ensure that the tire pressure is cor-
rect This has a direct influence on the park-
ing characteristics of the vehicle.
R if you mount wheels with a different wheel
size, this will have a direct influence on the
parking result.
R if you mount tires from another manufac-
turer, this may have an influence on the
parking result.
R if you drive slowly past the parking space, a
better parking result is achieved.
R pay attention to the PARKTRONIC warning
messages ( Y page
158) during the parking
procedure.
R you can intervene in the steering procedure
to correct it at any time. Parking assistance
will then be canceled and Active Parking
Assist stopped.
Use Active Parking Assist for parking spaces
that are:
R parallel or at right angles to the direction of
travel.
R on straight roads, not bends.
R on the same level as the road, e.g. not on
the pavement.
Detecting parking spaces G
WARNING
If there are objects above the detection
range:
R Active Parking Assist may steer too early
R the vehicle may not stop in front of these
objects
This could cause a collision. There is a risk
of an accident.
If objects are located above the detection
range, stop and deactivate Active Parking
Assist.
Objects located above the detection range of
Active Parking Assist will not be detected
when the parking space is measured. These
are not taken into account when the parking
procedure is calculated, e.g. overhanging
loads, overhangs or truck loading ramps.
Further information about the detection range
(Y page

157).160
Driving systems
Driving and parking