
Engine
Display messages Possible causes/consequences and
M
MSolutions ?
Coolant Too Hot Coolant Too Hot
Stop Vehicle Turn Stop Vehicle Turn
Engine Off Engine Off The coolant is too hot.
A warning tone also sounds.
G WARNING
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Ypage 104).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †).
Otherwise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120 †). The poly-V-belt may have torn.
X
Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Check the poly-V-belt.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is not damaged:
X Wait until the display message disappears before restarting the
engine. Otherwise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X Visit a qualified specialist workshop. 152
Display messagesOn-board computer and displays

Engine
Problem Possible causes/consequences and
M
MSolutions ?
The red coolant
warning lamp comes on
while the engine is
running. A warning tone
also sounds.
The coolant temperature has exceeded 248 ‡ (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.
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
X Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 104).
X Leave 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 203).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-start driving. Warning and indicator lamps in the instrument cluster
165On-board computer and displays Z

(20 cm) and more between the radiator and a
person's body (excluding extremities: hands,
wrists, feet and legs.) Declarations of conformity
Vehicle components which receive
and/or transmit radio waves
i USA only: The wireless devices of this
vehicle comply with Part 15 of the FCC
Rules. Operation is subject to the following
two conditions:
1. These devices may not cause harmful
interference, and
2. These devices must accept any
interference received, including
interference that may cause undesired
operation.
Changes or modifications not expressly
approved by the party responsible for
compliance could void the user's authority
to operate the equipment.
i Canada only: the wireless devices of this
vehicle comply with Industry Canada
license-exempt RSS standard(s). Operation
is subject to the following two conditions:
1. These devices may not cause harmful
interference, and
2. These devices must accept any
interference received, including
interference that may cause undesired
operation. Information on copyright
General information
Information on licenses for free and Open
Source software used in your vehicle and in
the electronic components can be found on
this website: http://www.mercedes-
benz.com/opensource . Registered trademarks
Registered trademarks:
R Bluetooth ®
is a registered trademark of
Bluetooth ®
SIG Inc.
R DTS is a registered trademark of DTS, Inc.
R Dolby and MLP are registered trademarks
of DOLBY Laboratories.
R BabySmart™, ESP ®
and PRE-SAFE ®
are
registered trademarks of Daimler AG.
R HomeLink ®
is a registered trademark of
Prince.
R iPod ®
and iTunes ®
are registered
trademarks of Apple Inc.
R Logic7 ®
is a registered trademark of
Harman International Industries.
R Microsoft ®
and Windows media ®
are
registered trademarks of Microsoft
Corporation.
R SIRIUS is a registered trademark of Sirius
XM Radio Inc.
R HD Radio is a registered trademark of
iBiquity Digital Corporation.
R Gracenote ®
is a registered trademark of
Gracenote, Inc.
R ZAGATSurvey ®
and related brands are
registered trademarks of ZagatSurvey,
LLC. Function restrictions
For safety reasons, some COMAND functions
are restricted or unavailable while the vehicle
is in motion. You will notice this, for example
because either you will not be able to select
certain menu items or COMAND will display
a message to this effect. Function restrictions
171COMAND Z

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Read the information on qualified
specialist workshops: (Y page 27).Engine compartment
Hood
Important safety notes G
WARNING
If the hood is unlatched, it may open up when
the vehicle is in motion and block your view.
There is a risk of an accident.
Never unlatch the hood while driving. G
WARNING
Certain components in the engine
compartment may be very hot, e.g. the drive
system and radiator. Working in the engine
compartment poses a risk of injury.
If possible, let the drive system cool down and
only touch the following described
components. G
WARNING
Opening the hood when the engine is
overheated 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
The engine compartment contains moving
components. Certain components, such as
the radiator fan, may continue to run or start
again suddenly when the ignition is off. There
is a risk of injury.
If you need to do any work inside the engine
compartment:
R switch off the ignition
R never reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area
R remove jewelery and watches
R keep items of clothing and hair, for
example, away from moving parts G
WARNING
The engine is equipped with a transistorized
ignition system. Because of the high voltage,
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnostic
socket) of the ignition system:
R with the engine running
R while starting the engine
R when the ignition is switched on and the
engine is turned manually G
WARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured
by the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
Do not touch the following when the ignition
is switched on:
R ignition coils
R spark plug connectors
R test socket 200
Engine compartmentMaintenance and care