check engine light MERCEDES-BENZ METRIS 2020 MY20 Operator’s Manual

Problems with the engine
Problem
Possible causes/consequences and
M SolutionsThe engine does not
start.
The starter motor can
be heard. There is a malfunction in the fuel supply.
X
Turn the key back to position g in the ignition lock before
attempting to start the engine again.
X Start the engine again.
Please bear in mind that lengthy and frequent starting attempts
will drain the battery.
If the engine does not start after several attempts: X Consult a qualified specialist workshop. The engine does not
start.
The starter motor can
be heard. The reserve
fuel warning lamp is lit
and the fuel gauge is at
0. The fuel tank has been run dry.
X Refuel the vehicle. The engine does not
start.
The starter motor can-
not be heard. The on-board voltage is too low. The battery is too weak or dis-
charged.
X Jump-start the vehicle ( Y page 272).
If the engine cannot be jump-started, the starter motor is faulty.
X Consult a qualified specialist workshop. The engine does not
start.
The starter motor can-
not be heard. The battery is discharged or faulty.
X
Check the battery for damage.
X Charge the battery (Y page
262).The engine is not run-
ning smoothly and is
misfiring. There is a malfunction in the engine electronics or a mechanical
component of the engine management system.
X Only depress the accelerator pedal slightly.
Unburnt fuel may otherwise get into the catalytic converter and
damage it.
X Have the cause rectified immediately at a qualified specialist
workshop. Automatic transmission
Important safety notes
G
WARNING
The vehicle can suddenly accelerate if the
engine speed is above the engine idling
speed and you then select transmission position h or k. There is a risk of an acci-
dent.
When engaging transmission position
h or
k at a standstill, always keep the brake
pedal depressed firmly and do not depress
the accelerator pedal at the same time. 130
Automatic transmission
Driving and parking

The rear view camera is a visual parking aid. It
shows you the area behind the vehicle in the
audio display.
The area behind the vehicle is displayed in a
mirrored fashion, as in the rear-view mirror or
the exterior mirrors. The guide lines displayed
assist you in backing up.
The message displays depend on the language
setting of the audio system. The following rear
view camera displays are examples.
Important safety notes !
Objects that are not at ground level appear
further away than they actually are, for
example:
R the bumper of the vehicle parked behind
R the drawbar of a trailer
R the ball coupling of a trailer tow hitch
R the tail-end of a truck
R slanted posts
Only use the camera guide lines for orienta-
tion. Do not get any closer to objects than
the lowest horizontal guide line. You may
otherwise damage your vehicle and/or the
object.
The rear view camera is only an aid. It cannot
replace your own awareness of the immediate
surroundings. You are responsible for safe
maneuvering and parking. Make sure that
there are no persons, animals or objects in the
maneuvering area while maneuvering and
parking in parking spaces.
The rear view camera may show obstacles in
perspectival distortion, incorrectly or not at all.
The rear view camera cannot display all
objects located very near and/or under the
rear bumper. It does not warn you of a colli-
sion, persons or objects.
Under the following circumstances, the rear
view camera will not function, or will function
in a limited manner:
R if the tailgate or rear-end door is open.
R if it is raining very heavily or snowing, or it is
foggy.
R at night or in very dark places.
R if the camera is exposed to very bright light.
White lines may appear in the camera image
R if the area is lit by fluorescent light, e.g.
from fluorescent lamps or LED lighting.
The camera image may flicker. R
if the camera lens fogs up, e.g. when driving
into a heated garage in winter, causing a
rapid change in temperature.
R the camera lens is dirty or obstructed.
Observe the notes on cleaning.
(Y page
267)
R if the rear of the vehicle is damaged.
In this case, have the camera position and
setting checked at a qualified specialist
workshop.
R the display has pixel errors.
Have the display repaired or replaced if usa-
bility is significantly reduced due to pixel
errors.
Do not use the rear view camera in these sit-
uations. You could otherwise injure others or
damage objects and the vehicle while parking
and maneuvering.
The field of vision and other functions of the
rear view camera may be restricted due to
additional accessories on the rear of the vehi-
cle (e.g. license plate holder, rear-mounted
bicycle rack).
Guide lines are always shown at road level. In
trailer mode, the guide lines are shown at the
level of the trailer coupling.
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 rear view camera cannot be precisely cali-
brated. The guide lines at road level or at the
level of the trailer tow hitch will not be dis-
played correctly.
In vehicles with a tailgate, the rear view cam-
era is protected from raindrops and dust by
means of a flap. When the rear view camera is
activated, this flap opens.
The flap closes again when:
R you have finished the maneuvering process
R you switch off the engine
For technical reasons, the flap may remain
open briefly after the rear view camera has
been deactivated. 164
Driving systems
Driving and parking

Observe the following when towing a trailer:
R Practice driving around bends, stopping and
backing up at a place where there is no traf-
fic. This enables you to gain experience and
get used to the new handling characteris-
tics.
R Before driving, check:
- that the trailer tow hitch and ball coupling
are secure
- that the safety switch for a braked trailer
is functioning properly
- that the safety chains are secure and not
damaged
- that the electrical connections are secure
- that the lights are working
- that the wheels are in good order and the
tire pressure is correct
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer is equipped with a separate
functional braking system, check before
each journey whether the brakes are func-
tioning correctly.
R Secure the load on the trailer according to
the applicable specifications and current
standards on securing loads
(Y page 244).
R When driving with a trailer, check at regular
intervals that the load is secured and that
the brakes and lights are working.
R Bear in mind that the handling will be less
stable when towing a trailer than when driv-
ing without one. Avoid sudden steering
movements.
R The vehicle/trailer combination is heavier,
accelerates more slowly and has a
decreased gradient climbing capability and a
longer braking distance.
It is more susceptible to crosswinds and
requires cautious steering.
R If possible, do not brake suddenly, but
rather moderately at first so that the trailer
can activate its brakes. Then increase the
force on the brake pedal.
R If the automatic transmission repeatedly
shifts between gears when driving on
inclines, restrict the shift range. Select shift
range 4, 3, 2 or 1.
Driving in a low gear and at a low speed
reduces the risk of damaging the engine. R
When driving on a downhill gradient, shift to
a low gear and take advantage of the
engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
R If the coolant temperature increases dra-
matically while the air-conditioning system
is switched on, switch off the air-condition-
ing system.
Coolant heat can also be dissipated by
switching the airflow and the temperature of
the air conditioning to the maximum level.
Open the windows if necessary.
R When overtaking, pay particular attention to
the extended length of your vehicle/trailer
combination.
Due to the length of your vehicle/trailer
combination you need an additional dis-
tance before you can return to your original
lane. Uncoupling a trailer
G
WARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun
brake is engaged.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound-
ing of the overrun brake.
X Make sure that the selector lever of the
automatic transmission is in position P.
X Engage the vehicle's parking brake.
X Close all doors.
X Apply the parking brake of the trailer.
X In addition, secure the trailer against rolling
away with a wheel chock or similar object.
X Remove the trailer cable and safety chains
and decouple the trailer. Towing a trailer
171
Driving and parking Z

Safety systems
Display messages
Possible causes/consequences and
M SolutionsABS, ESP Inopera‐
tive
+
ABS, BAS, hill start assist, and ESP
®
as well as its driving safety sys-
tems are unavailable due to a malfunction.
ATTENTION ASSIST is deactivated and other driving systems could
be automatically deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you brake
hard, for example.
This causes steerability and braking to be greatly impaired. The
braking distance can increase in emergency braking situations.
If ESP ®
is not operational, ESP ®
will not stabilize the vehicle.
There is an increased risk of skidding and accidents.
X Switch the engine off, wait briefly and start the engine again.
X Check if the display message has disappeared and ESP ®
is opera-
tional.
X If the display message continues to be displayed:
R Drive on with care.
R Visit a qualified specialist workshop immediately. ABS, ESP Curr.
Unavail.
+
ABS, BAS, hill start assist, and ESP
®
as well as its driving safety sys-
tems are temporarily unavailable.
ATTENTION ASSIST is deactivated and other driving systems could
be automatically deactivated.
For example, the on-board voltage may be insufficient.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you brake
hard, for example.
This causes steerability and braking to be greatly impaired. The
braking distance can increase in emergency braking situations.
If ESP ®
is not operational, ESP ®
will not stabilize the vehicle.
There is an increased risk of skidding and accidents.
X Drive on with care and on a suitable stretch of road make slight
steering movements at a speed above 12 mph (20 km/h ).
X Switch the engine off, wait briefly and start the engine again.
X Check if the display message has disappeared and ESP ®
is opera-
tional.
X If the display message continues to be displayed:
R Drive on with care.
R Visit a qualified specialist workshop immediately.196
Display messages (vehicles without steering wheel buttons)
On-board computer and displays

Display messages
Possible causes/consequences and
M Solutions÷
Inoperative
+ ESP
®
, BAS and hill start assist are unavailable due to a malfunction.
ATTENTION ASSIST is deactivated and other driving systems could
be automatically deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
will not stabilize the vehicle.
There is an increased risk of skidding and accidents.
X Switch the engine off, wait briefly and start the engine again.
X Check if the display message has disappeared and ESP ®
is opera-
tional.
X If the display message continues to be displayed:
R Drive on with care.
R Visit a qualified specialist workshop immediately. ÷
Currently Unavail.
+ ESP
®
, BAS and hill start assist are unavailable due to a malfunction.
The self-diagnosis function, for example, may not be complete.
ATTENTION ASSIST is deactivated and other driving systems could
be automatically deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you brake
hard, for example.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
will not stabilize the vehicle.
There is an increased risk of skidding and accidents.
X Drive on with care on a suitable stretch of road, making make
slight steering movements at a speed above
12 mph (20 km/h).
If the display message disappears, the functions mentioned
above are available again.
X Switch the engine off, wait briefly and start the engine again.
X Check if the display message has disappeared and ESP ®
is opera-
tional.
X If the display message continues to be displayed:
R Drive on with care.
R Visit a qualified specialist workshop immediately.200
Display messages (vehicles without steering wheel buttons)
On-board computer and displays

Display messages
Possible causes/consequences and
M SolutionsÐ
Power Steering Mal‐
function See Oper.
Manual An additional warning tone sounds. The steering power assistance
could be malfunctioning. You may need to steer more forcefully.
X Carefully continue to a qualified specialist workshop and have the
steering checked immediately. Â
Obtain a New Key The key needs to be replaced.
X Visit a qualified specialist workshop. Phone No Service Your vehicle is outside the network provider's transmitter/receiver
range. ¥
Check Washer Fluid The washer fluid level in the washer fluid reservoir has dropped
below the minimum.
X Add washer fluid (Y page 256).Indicator and warning lamps in the instrument cluster
General notes
When switching on the ignition, some systems carry out a self-test. Some indicator and warning
lamps may temporarily turn on or start to flash. This is not an indication of any problem. Only
when these indicator and warning lights turn on or start flashing after the engine has started or
during the journey has a malfunction occurred. Indicator and warning lamps in the instrument cluster
227
On-board computer and displays Z

Engine
Warning/
indicator
lamp
N Signal type
Possible causes/consequences and
M Solutions;
N The yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction in the following vehicle systems:
R in the engine management
R in the transmission management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with a gasoline engine)
R in the fuel system
The emission limit values may be exceeded and the engine may be running in
emergency mode.
X Have the vehicle checked as soon as possible at a qualified specialist work-
shop. 6
N The yellow reserve fuel warning lamp is on while the engine is running.
The fuel level has dropped to the reserve range.
X Refuel at the nearest gas station. ?
N The red coolant warning lamp comes on while the engine is running.
On vehicles without steering wheel buttons, the coolant temperature gauge is at
the start of the bar display
(Y page 178).
On vehicles with steering wheel buttons, the coolant temperature gauge is at
the start of the scale in the instrument cluster ( Y page 40).
The temperature sensor for the coolant temperature gauge is faulty.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine. Do not continue driving under any circumstances.
X Secure the vehicle to prevent it from rolling away (Y page
138).
X Consult a qualified specialist workshop. Indicator and warning lamps in the instrument cluster
233
On-board computer and displays Z

Warning/
indicator
lamp
N Signal type
Possible causes/consequences and
M SolutionsX
Secure the vehicle to prevent it from rolling away ( Y page 138).
X Exit the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
X Check the coolant level and add coolant, observing the warning notes
(Y page
253).
X If you have to add coolant more frequently, have the engine cooling system
checked.
X Make sure that the air supply to the radiator is not obstructed, by frozen
slush for example.
X Check the coolant temperature:
R using the display in the on-board computer on vehicles without steering
wheel buttons ( Y page

178)
R using the analog display in the instrument cluster on vehicles with steering
wheel buttons ( Y page 40)
X If the coolant temperature is below the maximum value specified below, you
can continue driving to the nearest qualified specialist workshop.
Avoid heavy loads on the engine, e.g. driving in mountainous terrain, and
stop-start traffic.
Under normal driving conditions and at the correct coolant level, the coolant
temperature display may rise to the letter H or to the red mark.Driving systems
Warning/
indicator
lamp
N Signal type
Possible causes/consequences and
M Solutions·
N The red distance warning lamp lights up while the vehicle is in motion.
The distance to the vehicle in front is too small for the speed selected.
X Increase the distance. ·
N The red distance warning lamp lights up while the vehicle is in motion. An
additional warning tone sounds.
You are approaching a vehicle or a stationary obstacle in your line of travel at
too high a speed.
X Be prepared to brake immediately.
X Pay particular attention to the traffic situation. You may have to brake or take
evasive action.
Further information about the distance warning function can be found under
"COLLISION PREVENTION ASSIST"
(Y page 149). Indicator and warning lamps in the instrument cluster
235
On-board computer and displays Z

X
Hold support strut ? and lift the hood
slightly.
X Guide support strut ? towards retainer =
and apply slight pressure to make it engage.
X Lower the hood and allow it to fall with
momentum from a height of approximately
1 ft (30 cm
).
The hood locks audibly.
X Check that the hood is correctly locked.
If the hood can be raised slightly, it is not
properly engaged. If the hood is not cor-
rectly engaged, open the hood again. Let
the hood fall with a little more momentum. Overview of the engine compart-
ment
Engine compartment (example)
:
Engine oil filler neck cap (Y page
252)
; Brake fluid reservoir cap (Y page
255)
= Coolant expansion tank cap ( Y page
253)
? Washer fluid reservoir cap (Y page
256)
Regularly check the fluid level and the assem-
bly for leaks. If you detect fluid loss, e.g. oil
stains on the vehicle parking space, consult a
qualified specialist workshop immediately. Engine oil
General notes !
Engine oil gets dirty in the course of opera-
tion and its quality and volume are gradually
diminished. Regularly check the oil level,
and top up or have it replaced as needed.
Observe the information on approved engine
oils and oil consumption under "Service prod-
ucts and capacities" ( Y page

308).You can check the oil level in the engine:
R with the oil dipstick
Checking the oil level using the oil dip-
stick G
WARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department. G
WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very
hot. Working in the engine compartment
poses a risk of injury.
Where possible, let the engine cool down
and touch only the components described in
the following. Oil dipstick and engine oil filler neck
Only check the oil level when the engine is at
normal operating temperature. X Stop your vehicle as far away from traffic as
possible on level ground.
X Secure the vehicle to prevent it from rolling
away.
X Switch off the engine.
X Wait for five minutes.252
Engine compartment
Maintenance and care

The prescribed service interval is based on
normal vehicle use. Service work will need to
be performed more frequently than prescribed
if the vehicle is operated under more arduous
conditions or with higher loads. Such arduous
conditions include:
R regular city driving with frequent intermedi-
ate stops
R driving predominantly short distances
R frequent operation in mountainous terrain or
on poor road surfaces
R leaving the engine idling for long periods on
a frequent basis
In these or similar operating conditions, have
the air filter, engine oil and oil filter, for exam-
ple, replaced more frequently. Under more
arduous operating conditions, the tires must
be checked more often. Further information
can be obtained at a qualified specialist work-
shop, e.g. an authorized Mercedes-Benz Com-
mercial Van Center.
Hiding service messages Vehicles without steering wheel buttons
X Press the 3 button on the instrument clus-
ter.
Vehicles with steering wheel buttons
X Press the a or % button on the steer-
ing wheel.
Calling up the service due date Vehicles without steering wheel buttons
The vehicle must be stationary. Use the but-
tons in the instrument cluster.
X Turn the key to position 2 in the ignition
lock.
X Press È to select the service display.
The display shows a possible service mes-
sage.
Vehicles with steering wheel buttons
Using the steering wheel buttons
X Turn the key to position 2 in the ignition
lock.
X Press = or ; to select the Service
menu.
X Press 9 or : to select the ASSYST
PLUS submenu and press a to confirm.
The display shows the service due date. Battery
Important safety notes
Work on the battery, e.g. removing or instal-
ling, requires specialist knowledge and the use
of special tools. Therefore, always have work
on the battery carried out at a qualified spe-
cialist workshop. G
WARNING
Work carried out incorrectly on the battery
can lead, for example, to a short circuit and
thus damage the vehicle electronics. This
can lead to function restrictions applying to
safety-relevant systems, e.g. the lighting
system, the ABS (anti-lock braking system)
or the ESP ®
(Electronic Stability Program).
The operating safety of your vehicle may be
restricted.
You could lose control of the vehicle, for
example:
R when braking
R in the event of abrupt steering maneuvers
and/or when the vehicle's speed is not
adapted to the road conditions
There is a risk of an accident.
In the event of a short circuit or a similar
incident, contact a qualified specialist work-
shop immediately. Do not drive any further.
You should have all work involving the bat-
tery carried out at a qualified specialist
workshop.
Further information can be found under "ABS"
(Y page
67) and under "ESP ®
" (Y page 68). G
WARNING
Electrostatic build-up can lead to the crea-
tion of sparks, which could ignite the highly
explosive gases of a battery. There is a risk
of an explosion.
Before handling the battery, touch the vehi-
cle body to remove any existing electrostatic
build-up.
The flammable gas mix is produced when the
battery is charged or when the vehicle is jump-
started. 258
Battery
Maintenance and care