2020 MERCEDES-BENZ METRIS alternator

Engine
Display messages
Possible causes/consequences and
M Solutions# An additional warning tone sounds. The battery is not being
charged.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
! Do not drive any further. Otherwise the engine may overheat.
X Secure the vehicle to prevent it from rolling away ( Y page 138).
X Consult a qualified specialist workshop. ?
Stop Vehicle Turn
Eng. Off An additional warning tone sounds. The coolant is too hot.
G WARNING
Never drive with an overheated engine. Driving when the engine is
overheated can cause fluids which may have leaked into the engine
compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the hood.
There is a risk of injury.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away ( Y page
138).
X Wait until the engine has cooled down.
X Make sure that the air supply to the radiator is not obstructed, by
frozen slush for example.
X Do not start the engine again until the display message goes out
and the coolant temperature is below the maximum value speci-
fied. The engine could otherwise be damaged.
X Pay attention to the coolant temperature gauge (Y page
178).
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal driving conditions and at the correct coolant level, the
coolant temperature gauge may rise to the letter H.204
Display messages (vehicles without steering wheel buttons)
On-board computer and displays

Engine
Display messages
Possible causes/consequences and
M Solutions# An additional warning tone sounds. The battery is not being
charged.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
! Do not drive any further. Otherwise the engine may overheat.
X Secure the vehicle to prevent it from rolling away ( Y page 138).
X Consult a qualified specialist workshop. ?
Coolant Too Hot:
Stop Vehicle Turn
Engine Off An additional warning tone sounds. The coolant is too hot.
G WARNING
Never drive with an overheated engine. Driving when the engine is
overheated can cause fluids which may have leaked into the engine
compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the hood.
There is a risk of injury.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Secure the vehicle to prevent it from rolling away ( Y page
138).
X Wait until the engine has cooled down.
X Make sure that the air supply to the radiator is not obstructed, by
frozen slush for example.
X Do not start the engine again until the display message goes out
and the coolant temperature is below the maximum value speci-
fied. The engine could otherwise be damaged.
X Monitor the ? coolant temperature gauge in the instrument
cluster.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and at the correct coolant level,
the display may rise to the red mark. Display messages (vehicles with steering wheel buttons)
219
On-board computer and displays Z

Disconnecting and removing
G
WARNING
During the charging process, a battery pro-
duces hydrogen gas. If a short circuit occurs
or sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a
connected battery does not come into
contact with vehicle parts.
R Never place metal objects or tools on a
battery.
R It is important that you observe the
described order of the battery terminals
when connecting and disconnecting a bat-
tery.
R When jump-starting, make sure that the
battery poles with identical polarity are
connected.
R It is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables.
R Never connect or disconnect the battery
terminals while the engine is running. G
WARNING
Battery acid is caustic. There is a risk of
injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean
over the battery. Keep children away from
batteries. Wash away battery acid immedi-
ately with plenty of clean water and seek
medical attention.
! You should have all work involving the bat-
tery carried out at a qualified specialist
workshop.
If, in exceptional circumstances, you need
to disconnect the battery yourself, please
make sure that:
R Secure the vehicle to prevent it from roll-
ing away.
R You have switched off the engine and
removed the key. Make sure the ignition
is switched off. Check to see that there
are no indicator lamps lighting in the instrument cluster. Electronic compo-
nents such as the alternator may other-
wise be damaged.
R After the battery has been disconnected,
the parking brake is automatically
engaged. You can then no longer move
the vehicle.
R For vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. You can
then no longer move the vehicle.
R You have first removed the negative ter-
minal and then the positive terminal.
Never mix up the terminal clamp discon-
nection/connection order and never mix
up the terminal clamps. The vehicle's
electronics may otherwise be damaged.
The battery and the cover of the positive ter-
minal clamp must be installed securely dur-
ing operation. Seat base (example: right-hand front seat)
The following description on disconnecting
and removing the battery is based upon the
example of the starter battery in the seat base
of the driver's seat. The additional battery is
disconnected and removed in the same way as
the starter battery. The auxiliary battery is
located in the seat base of the left-hand front
seat.
X Switch off all electrical consumers.
X Switch off the engine and remove the key
from the ignition lock.
X Open the front door on the right-hand side.
i To disconnect or remove the additional
battery, open the left-hand front door. The
auxiliary battery is located in the seat base
of the left-hand front seat. 260
BatteryMaintenance and care