2020 MERCEDES-BENZ METRIS warning

Assist is ready for use, the lane markings in
the symbol are shown as solid lines
;.
Setting the sensitivity of Lane Keeping
Assist X
In the Assist. menu on the on-board com-
puter, select the Lane Keeping Assist:
function
(Y page 191).
X Select Standard or Adaptive.
In the Standard setting, no warning vibration
occurs if:
R you operate the turn signal in the corre-
sponding direction. In this event, the warn-
ings are suppressed for a certain period of
time.
R a driving safety system, such as ABS, BAS or
ESP ®
, intervenes or performs a control
action.
When Adaptive is selected, there is also no
warning vibration when: R you accelerate hard, e.g. kickdown.
R brake sharply.
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
marking, the system differentiates between
various 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, such as 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. Alertness Assistant ATTENTION
ASSIST
General notes ATTENTION ASSIST helps you during long,
monotonous journeys such as on freeways and
interstate highways. It is active in the 40 mph
(

60 km/h) to 125 mph (200 km/h) range. If
ATTENTION ASSIST detects typical indicators of fatigue or increasing lapses in concentration
on the part of the driver, it suggests taking a
break.
Important safety notes ATTENTION ASSIST is only an aid. The system
may not always detect fatigue or lapses in
concentration until too late, or may not detect
them at all. ATTENTION ASSIST is not a substi-
tute for a well-rested and attentive driver.
The functionality of ATTENTION ASSIST is
restricted, and warnings may be delayed or
not occur at all:
R if the length of the journey is less than
approximately

30 minutes
R if the road condition is poor, e.g. if the sur-
face is uneven or if there are potholes
R if there is a strong side wind
R if you have adopted a sporty driving style
with high cornering speeds or high rates of
acceleration
R if you are predominantly driving at a speed
below 40 mph (60 km/h) or above 125 mph
(200 km/h)
R if the time has been set incorrectly
R in active driving situations, such as when
you change lanes or change your speed
ATTENTION ASSIST is reset and starts assess-
ing your attention again when you continue
your journey if:
R you switch off the engine
R you take off your seat belt and open the
driver's door, e.g. for a change of drivers or
to take a break
Displaying the attention level Driving systems
155
Driving and parking Z

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

Active Parking Assist does not assist you park-
ing in spaces at right angles to the direction of
travel if:
R two parking spaces are located directly next
to one another
R the parking space is directly next to a low
obstacle such as a low curb
R you forward park
Active Parking Assist does not assist you park-
ing in spaces that are parallel or at right angles
to the direction of travel if:
R the parking space is on a curb
R the system reads the parking space as being
blocked, for example by foliage or grass
paving blocks
R the area is too small for the vehicle to
maneuver into
R the parking space is bordered by an obsta-
cle, e.g. a tree, a post or a trailer :
Detected parking space on the left
; Parking symbol
= Detected parking space on the right
If the driver's seat belt is fastened and all
doors are closed, Active Parking Assist is acti-
vated automatically when driving forwards.
The system is operational at speeds of up to
approximately
22 mph (35 km/h). While in
operation, the system independently locates
and measures parking spaces on both sides of
the vehicle.
Active Parking Assist will only detect parking
spaces:
R parallel or at right angles to the direction of
travel
R that are parallel to the direction of travel
and are at least 59 in (1.5 m) wide
R that are parallel to the direction of travel
and at least 40 in (1.0 m) longer than your
vehicle
R that are at right angles to the direction of
travel and at least 40 in (1.0 m) wider than
your vehicle i
Note that Active Parking Assist cannot
measure the length of a parking space if it is
at right angles to the direction of travel. You
will need to judge whether your vehicle will
fit in the parking space.
When the vehicle is driving at speeds of up to
approximately

20 mph (30 km/h), parking
symbol ; is shown as a status display in the
header.
The system detects and differentiates between
parking spaces which are parallel or at right
angles to the direction of travel. When a park-
ing space is detected, an arrow appears next
to parking symbol ; to indicate which side
the parking space is on. The parking space is
displayed while you are driving past it and until
you are approximately 50 ft (15 m) away from
it.
Active Parking Assist displays parking spaces
on the passenger side as standard. The park-
ing spaces on the driver's side are only dis-
played if you operate the turn signal on the
driver's side. When parking on the driver's
side, you must operate the turn signal until
you have started active parking assistance by
pressing the a button on the steering
wheel.
Parking G
WARNING
If you leave the driver's seat when the vehi-
cle is only being braked by Active Parking
Assist, the vehicle could roll away if:
R there is a malfunction in the system or in
the voltage supply.
R the electrical system in the engine com-
partment, the battery or the fuses are
tampered with.
R the battery is disconnected.
R the vehicle is accelerated, e.g. by a vehi-
cle occupant.
There is a risk of an accident.
Before leaving the driver's seat, always
secure the vehicle against rolling away.
If PARKTRONIC detects obstacles, Active Park-
ing Assist brakes automatically during the
parking process. You are responsible for brak-
ing in good time. Driving systems
161
Driving and parking Z

X
Start the engine.
X Switch on the turn signal in the direction in
which you are pulling away.
X Shift the transmission to position h or k.
The display shows the message Start
Park Assist? Yes: OK No: %.
X To cancel the process: press the % but-
ton on the steering wheel or drive off.
or
X To exit the parking space using active
parking assistance: press the a button
on the steering wheel.
The display shows the message Park
Assist Active: Accelerate and Brake
Obs. Surroundings.
X Let go of the steering wheel.
X Pull away, being ready to brake at all times.
Exit the parking space slowly and do not
drive faster than
6 mph (10 km/h). Other-
wise parking assistance is canceled and
Active Parking Assist is stopped.
Active Parking Assist brakes the vehicle to a
standstill when the vehicle approaches a
border of the parking space.
X While the vehicle is stationary, shift the
transmission to position h or k as
required or according to the message.
Active Parking Assist immediately steers in
the other direction. The display shows the
message Park Assist Active: Acceler‐
ate and Brake Obs. Surroundings.
i You will achieve the best results by waiting
for the steering procedure to complete
before pulling away.
If you back up after activation, the steering
wheel is moved to the straight-ahead posi-
tion.
X Drive forwards and reverse as prompted by
the PARKTRONIC warning displays, several
times if necessary.
Once you have exited the parking space com-
pletely:
R The display shows the Park Assist Fin‐
ished message.
R A tone sounds.
R The steering wheel is moved to the straight-
ahead position
The parking assistance function of Active Park-
ing Assist is stopped. You will then have to
steer and merge into traffic on your own.
PARKTRONIC is still available. You can take over the steering before the vehi-
cle has exited the parking space completely.
This is useful, for example when you recognize
that it is already possible to pull out of the
parking space.
Canceling active parking assistance X
Stop the movement of the steering wheel or
steer yourself.
or X Press the f button and deactivate
PARKTRONIC
(Y page 158).
Parking assistance is canceled immediately
and Active Parking Assist is stopped. The
display shows the Park Assist Canceled
message.
Active parking assistance is canceled automat-
ically in the following cases:
R you apply the parking brake.
R parking using Active Parking Assist is no
longer possible.
R you are driving faster than

6 mph
(10 km/h).
R a wheel spins and ESP ®
intervenes or fails.
The ÷ warning lamp in the instrument
cluster then lights up.
R you unfasten your seat belt.
R you open a door or the tailgate/rear-end
door.
R you shift the transmission to position j.
A warning tone sounds, the parking symbol in
the display goes out and the Park Assist
Canceled message appears.
Once active Parking Assist has been canceled,
you must steer and brake again yourself.
If a system malfunction occurs, vehicles are
automatically braked down to a standstill. To
continue driving, you must depress the accel-
erator pedal again. Rear view camera
General notes On vehicles with a tailgate, the rear view cam-
era is next to the tailgate handle
(
Y page

267).
On vehicles with rear-end doors, the rear view
camera is in the top of the license plate mold-
ing ( Y page 267). Driving systems
163
Driving and parking Z