2012 MERCEDES-BENZ E-Class CABRIOLET coolant

ProblemPossible causes/consequences and M SolutionsThe engine is not
running smoothly and
is misfiring.There is a malfunction in the engine electronics or a mechanical
component of the engine management system.XOnly depress the accelerator pedal slightly.XHave the cause rectified immediately at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz Center.
Otherwise, non-combusted fuel may get into the catalytic
converter and damage it.The coolant
temperature gauge
shows a value above
248 ‡ (120 †).The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.XStop as soon as possible and allow the engine and the coolant
to cool down.XCheck the coolant level ( Y page 276). Observe the warning
notes as you do so and add coolant if necessary.Automatic transmission
Important safety notes
GWARNING
It is dangerous to shift the automatic
transmission out of parking position P or
neutral position N if the engine speed is
higher than idle speed. If your foot is not firmly
on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.
GWARNING
Keep in mind that turning off the engine alone
only will shift the automatic transmission into
neutral position N automatically.
Always shift the automatic transmission into
park position P before turning off the engine.
Otherwise the vehicle could roll away which
could result in an accident and/or serious
personal injury.
Selector lever
Overview of transmission positions
Selector lever
PPark position with selector lever lockRReverse gearNNeutralDDriveAutomatic transmission149Driving and parkingZ

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 Please read the information on qualified
specialist workshops ( Y page 23).
Important safety notes
You will find an illustration of the instrument
cluster in the "At a glance" section
( Y page 27).
GWARNING
A driver's attention to the road and traffic
conditions must always be his/her primary
focus when driving.
For your safety and the safety of others,
selecting features through the multifunction
steering wheel should only be done by the
driver when traffic and road conditions permit
it to be done safely.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h ), your vehicle is
covering a distance of 44 feet (approximately
14 m) every second.
GWARNING
No messages will be displayed if either the
instrument cluster or the multifunction
display is inoperative.
As a result, you will not be able to see
information about your driving conditions,
such as
R speed
R outside temperature
R warning/indicator lamps
Rmalfunction/warning messages
R failure of any systems
Driving characteristics may be impaired.
If you must continue to drive, do so with added
caution. Contact an authorized Mercedes-
Benz Center as soon as possible.GWARNING
Malfunction and warning messages are only
indicated for certain systems and are
intentionally not very detailed. The
malfunction and warning messages are
simply a reminder with respect to the
operation of certain systems. They do not
replace the owner's and/or driver's
responsibility to maintain the vehicle's
operating safety. Have all required
maintenance and safety checks performed on
the vehicle. Bring the vehicle to an authorized
Mercedes-Benz Center to address the
malfunction and warning messages.
Displays and operation
Coolant temperature display
GWARNING
Driving when your engine is overheated can
cause some fluids which may have leaked into
the engine compartment to catch fire. You
could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until
the engine has cooled down.
The coolant temperature gauge is in the
instrument cluster on the right-hand side.
Under normal operating conditions and with
the specified coolant level, the coolant
temperature may rise to 248 ‡ (120 †).
196Displays and operationOn-board computer and displays

! If the coolant temperature is too high a
display message is shown.
If the coolant temperature rises above
248 ‡(120 †), do not drive any further as
this could damage the engine.
Tachometer
The red band in the tachometer indicates the
engine's overrevving range.
! Do not drive in the overrevving range, as
this could damage the engine.
The fuel supply is interrupted to protect the
engine when the red band is reached.
Outside temperature display
The outside temperature display is in the
multifunction display ( Y page 198).
GWARNING
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
Changes in the outside temperature are
displayed after a short delay.
Speedometer with segments
The segments in the speedometer indicate
which speed range is available.
Cruise control ( Y page 164) activated:
The segments light up from the stored speed
to the maximum speed.
DISTRONIC PLUS ( Y page 166) activated:
One or two segments in the set speed range
light up.
DISTRONIC PLUS detects a vehicle in front:
The segments between the speed of the
vehicle in front and the stored speed light up.
Operating the on-board computer
Overview
The on-board computer is activated as soon
as you turn the SmartKey to position 1 in the
ignition lock.
You can control the multifunction display and
the settings in the on-board computer using
the buttons on the multifunction steering
wheel.
:Multifunction display;To switch on the Voice Control System;
see the separate operating instructions=Right control panel?Left control panelABack buttonDisplays and operation197On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutionsb
AUTO Lamp Function
InoperativeThe light sensor is defective.XVisit a qualified specialist workshop.b
Switch Off LightsThe lights are still switched on when you leave the vehicle. A
warning tone also sounds.XTurn the light switch to c or à .Adaptive Highbeam
Assist InoperativeAdaptive Highbeam Assist is faulty.XVisit a qualified specialist workshop.Adaptive Highbeam
Assist Currently
Unavailable See
Operator's ManualAdaptive Highbeam Assist is deactivated and temporarily
inoperative. Possible causes are:
R the windshield in the camera's field of vision is dirty.
R visibility is impaired due to heavy rain, snow or fog.XClean the windshield.
If the system detects that the camera is fully functional again, the
Adaptive Highbeam Assist Now Available display message
is shown.
Adaptive Highbeam Assist is operational again.
Engine
Display messagesPossible causes/consequences and M Solutions+
Check Coolant
Level See
Operator's ManualThe coolant level is too low.XAdd coolant, observing the warning notes when doing so
( Y page 276).XIf coolant needs to be added more often than usual, have the
engine coolant system checked at a qualified specialist
workshop.GWARNING
Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn
if it comes into contact with hot engine parts. You could be seriously burned.
! The coolant level is too low. Avoid making long journeys with too little coolant in the cooling
system. The engine will otherwise be damaged.
The display messages and the corresponding symbol that indicate that the coolant level is
too low must not be ignored.
Display messages225On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutions?
Coolant Level Low
Stop Vehicle Turn
Engine OffThe coolant is too hot.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.XWait until the display message disappears before restarting the
engine. Otherwise, there is a risk of engine damage.XPay attention to the coolant temperature display.XIf the temperature increases again, visit a qualified specialist
workshop immediately.The poly-V-belt may have torn.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is not damaged:
XWait until the display message disappears before restarting the
engine. Otherwise, there is a risk of engine damage.XPay attention to the coolant temperature display.XVisit a qualified specialist workshop.GWARNING
Driving when your engine is overheated can cause some fluids which may have leaked into the
engine compartment to catch fire. You could be seriously burned.
Steam from an overheated engine can cause serious burns which can occur just by opening the
engine hood. Stay away from the engine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until the engine has cooled down.
! If the coolant temperature exceeds 248 ‡(120 †) do not continue driving. The engine will
otherwise be damaged.
226Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M Solutions?The engine fan is defective.XAt coolant temperatures under 248 ‡ (120 † ), drive to the next
qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.#The battery is not being charged.
Possible causes are:
R a defective alternator
R a torn poly-V-belt
R a malfunction in the electronicsXPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is not damaged:
XVisit a qualified specialist workshop.4
Check Engine Oil
At Next RefuelingThe engine oil level has dropped to the minimum level.
A warning tone also sounds.XCheck the engine oil level at the latest when next refueling
( Y page 275).XIf necessary, add engine oil ( Y page 275).XIf engine oil needs to be added more often than usual, have the
engine checked at a qualified specialist workshop.
Information on approved engine oils can be obtained from any qualified specialist workshop
or on the Internet at http://www.mbusa.com (USA only).
! The oil level is too low. Avoid long journeys with too little engine oil. There is a risk of
engine damage.
The display messages and the corresponding symbol that indicate that the oil level is too
low must not be ignored.
Display messages227On-board computer and displaysZ

ProblemPossible causes/consequences and M Solutions?
The red coolant
warning lamp lights up
while the engine is
running and the coolant
temperature gauge is
at the start of the scale.The temperature sensor for the coolant temperature gauge is
defective.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.XApply the parking brake.XConsult a qualified specialist workshop.246Warning and indicator lamps in the instrument clusterOn-board computer and displays

ProblemPossible causes/consequences and M Solutions?
The red coolant
warning lamp comes on
while the engine is
running.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
malfunctioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.XObserve the additional display messages in the multifunction
display.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XAllow the engine and coolant to cool.XCheck the coolant level and add coolant (Y page 276). Observe
the warning notes.XIf you need to add coolant more often than usual, have the
engine coolant system checked.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.XAt coolant temperatures under 248 ‡ (120 † ), drive to the next
qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.?
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.
The engine is not being cooled sufficiently and may be damaged.XObserve the additional display messages in the multifunction
display.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XAllow the engine and coolant to cool.XCheck the coolant level and add coolant (Y page 276). Observe
the warning notes.XIf you need to add coolant more often than usual, have the
engine coolant system checked.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.XAt coolant temperatures under 248 ‡ (120 † ), drive to the next
qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.Warning and indicator lamps in the instrument cluster247On-board computer and displaysZ