Engine
Display messages
Possible causes/consequences and
M
MSolutions +
Top Top
up
upcoolant
coolant See
See
Owner's Manual
Owner's Manual The coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, observing the warning notes before doing so
(Y page 326).
If you have to top up the coolant frequently:
X Contact a qualified specialist workshop and have the engine
cooling system checked. ? The fan motor is faulty.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g.
driving in mountainous terrain and stop-start traffic. ?
Coolant Stop vehi‐ Coolant Stop vehi‐
cle Switch engine cle Switch engine
off off The coolant is too hot.
A warning tone also sounds.
G WARNING
Never drive with an overheated engine. Driving when your engine is overheated can cause some 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 bonnet.
There is a risk of injury.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 184).
X Wait until the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 120 †. The engine may
otherwise be damaged.
X Pay attention to the coolant temperature display.
If the temperature increases again:
X Consult a qualified specialist workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 120 †. Display messages
275On-board computer/Displays Z
Display messages
Possible causes/consequences and
M
MSolutions #
See Owner's Manual See Owner's Manual The battery is not being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
! Do not continue driving. The engine could otherwise overheat.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 184).
X Consult a qualified specialist workshop. #
Stop vehicle See Stop vehicle See
Owner's Manual Owner's Manual The battery is no longer being charged and the battery charge level
is too low.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 184).
X Observe the instructions in the #See Owner's Manual See Owner's Manual
display message.
X Consult a qualified specialist workshop. 4
Check eng. oil Check eng. oil
lev. when next lev. when next
refuelling refuelling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
! Avoid long journeys when there is too little coolant in the cool-
ing system. Otherwise the engine will be damaged.
X Check the oil level when next refuelling, at the latest
(Y page 324).
X If necessary, top up the engine oil (Y page 325).
If the engine oil needs topping up more often:
X Contact a qualified specialist workshop and have the engine
checked.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.com. 276
Display
messagesOn-board computer/Displays
Display messages
Possible causes/consequences and
M
MSolutions 4
Add Add
1
1litre
litre engine
engine
oil
oil when
when next
next refu‐
refu‐
elling
elling The engine oil level has dropped to the minimum level.
! Avoid long journeys when there is too little coolant in the cool-
ing system. Otherwise the engine will be damaged.
X Check the oil level when next refuelling, at the latest
(Y page 324).
X If necessary, top up the engine oil (Y page 325).
If the engine oil needs topping up more often:
X Contact a qualified specialist workshop and have the engine
checked.
Information on approved engine oils can be obtained from any
qualified specialist workshop or on the Internet at http://
bevo.mercedes-benz.co m.4
Engine oil level Engine oil level
Stop vehicle Stop vehicle
Switch engine off Switch engine off The engine oil level is too low. There is a risk of engine damage.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 184).
X Check the engine oil level (Y page 324).
X If necessary, top up the engine oil (Y page 325).æ
Reserve fuel level Reserve fuel level The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level
drops into the reserve range.
X Refuel at the nearest filling station. ç There is very little fuel in the fuel tank.
The auxiliary heating cannot be operated.
X Refuel at the nearest filling station without fail. ¸
Replace Replace
air
aircleaner
cleaner Vehicles with a diesel engine: the engine air filter is dirty and must
be replaced.
X Consult a qualified specialist workshop. !
Clean Clean
the
thefuel
fuel fil‐
fil‐
ter
ter Vehicles with a diesel engine: there is water in the fuel filter. The
water must be drained off.
X Consult a qualified specialist workshop. Display messages
277On-board computer/Displays Z
Engine
Problem
Possible causes/consequences and
M
MSolutions ;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running. There may be a fault, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engine may be running in emergency mode.
X Consult a qualified specialist workshop immediately. Vehicles with a diesel engine: the fuel tank has been run dry
(Y
page 183).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emer-
gency running mode is cancelled. The vehicle need not be
checked. æ
The yellow reserve fuel
warning lamp is on
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level
drops into the reserve range.
X Refuel at the nearest filling station. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the start of the scale. 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 traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.
X Safeguard the vehicle against rolling away (Y page 184).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
301On-board computer/Displays Z
Problem
Possible causes/consequences and
M
MSolutions ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may
be blocked or the electric engine radiator fan may be malfunc-
tioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 184).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 326).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the coolant temperature is
below 120 †. The engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g.
driving in mountainous terrain and stop-start traffic. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
The coolant temperature has exceeded 120 †. The airflow to the
engine radiator may be blocked or the coolant level may be too
low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine is overheated can cause some 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 bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 184).302
Warning and indicator lamps in the instrument clusterOn-board computer/Displays
Problem
Possible causes/consequences and
M
MSolutions X
Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 326).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g.
driving in mountainous terrain and stop-start traffic. Driving systems
Problem
Possible causes/consequences and
M MSolutions ·
The red distance warn-
ing 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. ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. A warning tone also
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 careful attention to the traffic situation. You may have to
brake or take evasive action.
For further information on the distance warning function of COL-
LISION PREVENTION ASSIST PLUS, see (Y page 70).Warning and indicator lamps in the instrument cluster
303On-board computer/Displays Z
Damage to the engine or exhaust system is
caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R changing the engine oil and oil filter after
missing the change interval required by
the service system
R using engine oil additives
! Do not add too much oil. Topping up with
too much engine oil can result in damage to
the engine or to the catalytic converter.
Have excess engine oil siphoned off. Example: engine oil filler cap
X Turn cap :anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, top up with 1.0 lof engine
oil.
X Replace cap :on the filler neck and turn
clockwise.
Make sure that the cap locks securely into place.
X Check the oil level again with the oil dip-
stick (Y page 324).
For further information on engine oil, see
(Y page 400). Checking and adding other service
products
Checking the coolant level G
WARNING
The cooling system is pressurised, particu-
larly when the engine is warm. If you open the cap, you could be scalded if hot coolant
sprays out. There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Open
the cap slowly to release the pressure.
! The coolant level must only be checked
and corrected when the engine has cooled
down (coolant temperature under 40 †).
Checking the coolant level when the cool-
ant temperature is over 40 † can lead to
damage to the engine or engine cooling
system. Example
X Park the vehicle on a level surface.
Only check the coolant level if the vehicle is
on a level surface and the engine has
cooled down.
X Turn the key to position 2in the ignition
lock (Y page 157).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
40 †.
X Turn the key to position 0in the ignition
lock (Y page 157). 326
Engine compartmentMaintenance and care
X
Slowly turn cap :anti-clockwise to allow
excess pressure to escape.
X Turn cap :further anti-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough coolant in coolant expansion tank ;.
X If necessary, top up with coolant that has
been tested and approved by Mercedes-
Benz.
X Replace cap :and turn it clockwise as far
as it will go.
For further information on coolant, see
(Y page 402).
Topping up the windscreen washer sys-
tem/headlamp cleaning system G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
If windscreen washer concentrate comes into contact with hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure the windscreen washer concen-
trate does not come into contact with the filler neck. X
To open: pull cap:upwards by the tab.
X Top up with the premixed washer fluid.
X To close: press cap :onto the filler neck
until it engages.
If the washer fluid level drops below the rec-
ommended minimum of 1 litre, a message
appears in the multifunction display prompt-
ing you to top up the washer fluid
(Y page 290).
Further information on windscreen washer
fluid/antifreeze (Y page 403). ASSYST PLUS
Service message
The ASSYST PLUS service interval display
informs you of the next service due date.
You can find information on the type of ser-
vice and service intervals in the Service Book- let.
You can obtain further information from a
Mercedes-Benz Service Centre.
i The ASSYST PLUS service interval display
does not show any information on the
engine oil level. Observe the notes on the
engine oil level (Y page 324).
The multifunction display shows a service
message for a few seconds, e.g.: R Service A in .. days Service A in .. days
R Service A due
Service A due
R Service A overdue by .. days
Service A overdue by .. days ASSYST PLUS
327Maintenance and care Z