In particular, the detection of obstacles can
be impaired if:R dirt on the sensors or anything else cover-
ing the sensors
R poor visibility, e.g. due to rain, snow or
spray
Vehicles in the monitoring range are then not
indicated.
Active Blind Spot Assist may not detect nar-
row vehicles, such as motorcycles or bicy-
cles, or may only detect them too late.
Active Blind Spot Assist monitors the area up
to 10 ft (3 m) behind your vehicle and directly next to your vehicle, as shown in the diagram.
For this purpose, Active Blind Spot Assist
uses radar sensors in the rear bumper.
If the lanes are narrow, vehicles driving in the
lane beyond the lane next to your vehicle may
be indicated, especially if the vehicles are not
driving in the middle of their lane. This may be the case if there are vehicles driving at the
inner edge of their lanes.
Due to the nature of the system:
R warnings may be issued in error when driv-
ing close to crash barriers or similar solid
lane borders.
R the warning is canceled when driving for an
extended period next to long vehicles, such
as trucks. Two Active Blind Spot Assist radar sensors
are integrated into the front and rear bumpers
respectively. An additional radar sensor is
located behind the cover in the radiator grill.
Make sure that the sensors and areas around
them are free of dirt, ice or slush. The rear
sensors must not be covered, for example by cycle racks or overhanging cargo. Following a
severe impact or in the event of damage to
the bumpers, have the function of the sensors checked at a qualified specialist workshop.
Blind Spot Assist may otherwise not work
properly.
Indicator and warning display
Active Blind Spot Assist is not active at
speeds below approximately 20 mph
(30 km/h). Vehicles in the monitoring range
are then not indicated.
:Yellow indicator lamp/red warning lamp
When Active Blind Spot Assist is activated,
indicator lamp : in the exterior mirrors lights
up yellow at speeds of up to 20 mph
(30 km/h). At speeds above 20 mph
(30 km/h), the indicator lamp goes out and
Active Blind Spot Assist is operational.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp : on the corre-
sponding side lights up red. This warning is
always emitted when a vehicle enters the
blind spot monitoring range from behind or
from the side. When you overtake a vehicle,
the warning only occurs if the difference in
speed is less than 7 mph (12 km/h).
208Driving systems
Driving and parking
Display messagesPossible causes/consequences and M Solutions
PRE-SAFE
Functions CurZ
rently Limited See
Operator's Manual
PRE-SAFE®
Brake is temporarily inoperative. Possible causes are:
R function is impaired due to heavy rain or snow.
R the sensors in the radiator trim and the bumper are dirty.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
When the causes stated above no longer apply, the display mes-
sage disappears.
PRE
Display messagesPossible causes/consequences and M Solutions
?
Coolant Too Hot
Stop Vehicle Turn
Engine Off
The coolant is too hot.
A warning tone also sounds.
GWARNING
Do not drive when your engine is overheated. This can ca use 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 ( Y page 168).
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 snow, slush or ice.
X Do not start the engine again until the display message g oes out
and the coolant temperature is below 248 ‡ (120 †). Other-
wise, 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 †).
Display messages247
On-board computer and displays
Z
Display messagesPossible causes/consequences and M Solutions
Park Assist InoperZ
ative
You have just carried out a large number of turning or parking
maneuvers.
Active Parking Assist will become available again after approx -
imately ten minutes ( Y page 189).
X Pull over and stop the vehicle safely as soon as possible, p aying
attention to road and traffic conditions.
X Switch off and restart the engine.
If the display message continues to be displayed: X Visit a qualified specialist workshop.
PARKTRONIC is defective.
X Visit a qualified specialist workshop.
Park Assist FinZ
ished
The vehicle is parked. A warning tone also sounds.
The display message disappears automatically.
DISTRONIC PLUS OffDISTRONIC PLUS has been deactivated ( Y page 176). If it was
deactivated automatically, a warning tone also sounds.
DISTRONIC PLUS Now
Available
DISTRONIC PLUS is operational again after having been tempo-
rarily unavailable. You can now reactivate DISTRONIC PLUS
( Y page 176).
DISTRONIC PLUS CurZ
rently Unavailable
See Operator's ManZ
ual
DISTRONIC PLUS is temporarily inoperative. Possible cause s are:
R function is impaired due to heavy rain or snow.
R the sensors in the radiator trim and the bumper are dirty.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
A warning tone also sounds.
When the causes stated above no longer apply, the display mes-
sage disappears.
DISTRONIC PLUS is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, p aying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 168).
X Clean the sensors in the radiator grill and the bumper
(Y page 309).
X Restart the engine.
Display messages253
On-board computer and displays
Z
ProblemPossible causes/consequences and M Solutions
?
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 eng ine 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 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 168).
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 snow, slush or ice.
X Check the coolant level and add coolant ( Y page 303). Observe
the warning notes.
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. drivin g in moun-
tainous terrain, and stop-and-go 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 248 ‡ (120 †). The air-
flow to the engine radiator may be blocked or the coo lant level may
be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can ca use 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 168).
X Wait until the engine has cooled down.
Warning and indicator lamps in the instrument cluster269
On-board computer and displays
Z
ProblemPossible causes/consequences and M Solutions
X
Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Check the coolant level and add coolant ( Y page 303). Observe
the warning notes.
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. drivin g in moun-
tainous terrain, and stop-and-go traffic.
Driving systems
ProblemPossible causes/consequences and M Solutions
·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. A warning tone also
sounds.GWARNING
You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
There is a risk of an accident.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
More information about DISTRONIC PLUS ( Y page 176) and
PRE
Useful information
iThis Operator's Manual describes all
models and all standard and optional equip- ment 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.
iRead the information on qualified special-
ist workshops ( Y page 27).
Engine compartment
Hood
Important safety notes
GWARNING
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. Before
every trip, ensure that the hood is locked.
GWARNING
When opening and closing the hood, it may
suddenly fall into the closed position. There is a risk of injury to persons within range of
movement of the hood.
Open and close the hood only when no one is
within its range of movement.
GWARNING
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.
GWARNING
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 jewelry and watches
R keep items of clothing and hair, for exam-
ple, away from moving parts
GWARNING
The ignition system and the fuel injection sys-
tem work under high voltage. If you touch
components which are under voltage, you
could get an electric shock. There is a risk of
injury.
Never touch components of the ignition sys-
tem or fuel injection system when the ignition is switched on.
Opening the hood
GWARNING
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.
GWARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured bythe wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
300Engine compartment
Maintenance and care
! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
X Make sure that the windshield wipers are
turned off.
XPull release lever : on the hood.
The hood is released.
X Reach into the gap, pull hood catch han-
dle ; up and lift the hood.
If you lift the hood by approximately 15 in
(40 cm), the hood is opened and held open automatically by the gas-filled strut.
Closing the hood
X Lower the hood and let it fall from a height
of approximately 8 in (20 cm).
X Check that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force.
Engine oil
General notes on the oil level
Depending on your driving style, the vehicle
consumes up to 0.9 US qt (0.8 liters) of oil per
600 miles (1,000 km). The oil consumption
may be higher than this when the vehicle is
new or if you frequently drive at high engine
speeds.
Depending on the engine, the oil dipstick may be in a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly, wait about 30 minutes
before carrying out the measurement.
Checking the oil level using the oil dip-
stick
GWARNING
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.
Example: vehicles with a gasoline engine
Engine compartment301
Maintenance and care
Z