EngineProblemPossible causes/consequences and M Solutions;
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.XHave the vehicle checked as soon as possible at a qualified
specialist workshop.Vehicles with a diesel engine: the fuel tank has been run dry
( Y page 161).XStart 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 lights up
while the engine is run-
ning.The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated when the fuel level
drops into the reserve range.XRefuel 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.XStop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.XSecure the vehicle against rolling away ( Y page 162).XConsult a qualified specialist workshop.262Warning and indicator lamps in the instrument clusterOn-board computer and displays
ProCarManuals.com
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 engine radiator
may be blocked or the electric engine radiator fan may be mal-
functioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.XObserve the additional display messages in the multifunction
display.XStop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.XSecure the vehicle against rolling away ( Y page 162).XLeave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.XCheck the coolant level and top up the coolant ( Y page 285).
Observe the warning notes as you do so.XIf you have to top up the coolant frequently, have the engine
cooling system checked.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.XDo not start the engine again until the coolant temperature is
below 120 †. The engine may otherwise be damaged.XDrive to the nearest qualified specialist workshop.XAvoid heavy loads on the engine 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.GWARNING
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.
Steam from an overheated engine can cause serious burns which
can occur just by opening the bonnet.
This poses a risk of injury.
XObserve the additional display messages in the multifunction
display.XStop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.XSecure the vehicle against rolling away ( Y page 162).Warning and indicator lamps in the instrument cluster263On-board computer and displaysZProCarManuals.com
ProblemPossible causes/consequences and M SolutionsXLeave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.XCheck the coolant level and top up the coolant ( Y page 285).
Observe the warning notes as you do so.XIf you have to top up the coolant frequently, have the engine
cooling system checked.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.XIf the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.XAvoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic.
Driving systems
ProblemPossible causes/consequences and M Solutions·
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.XIncrease 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.XBe prepared to brake immediately.XPay careful attention to the traffic situation. You may have to
brake or take evasive action.
For further information about the distance warning function of
COLLISION PREVENTION ASSIST ( Y page 65).
For further information about COLLISION PREVENTION ASSIST
PLUS ( Y page 67).
264Warning and indicator lamps in the instrument clusterOn-board computer and displays
ProCarManuals.com
TyresProblemPossible causes/consequences and M Solutionsh
The yellow tyre pres-
sure monitor warning
lamp (pressure loss/
malfunction) is lit.The tyre pressure monitor has detected a loss of pressure in at
least one of the tyres.GWARNING
With tyre pressures which are too low, there is a risk of the fol-
lowing hazards:
R the tyres may burst, especially as the load and vehicle speed
increase.
R the tyres may wear excessively and/or unevenly, which may
greatly impair tyre traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do
so.XSecure the vehicle against rolling away ( Y page 162).XObserve the additional display messages in the multifunction
display.XCheck the tyres and, if necessary, follow the instructions for a
flat tyre ( Y page 298).XCheck the tyre pressure ( Y page 322).XIf necessary, correct the tyre pressure.h
The yellow tyre pres-
sure monitor warning
lamp (pressure loss/
malfunction) flashes for
approximately one
minute and then
remains lit.The tyre pressure monitor is faulty.GWARNING
The system is possibly unable to recognise or register low tyre
pressure.
There is a risk of an accident.
XObserve the additional display messages in the multifunction
display.XVisit a qualified specialist workshop.Warning and indicator lamps in the instrument cluster265On-board computer and displaysZProCarManuals.com
Checking the coolant level when the cool-
ant temperature is over 40 † can lead to
damage to the engine or engine cooling
system.
Example
XPark 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.XTurn the key to position 2 in the ignition
lock ( Y page 145).XCheck the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
40 †.XTurn the key to position 0 (Y page 145) in
the ignition lock.XSlowly turn cap : half a turn anti-clock-
wise to allow excess pressure to escape.XTurn 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 ;.XIf necessary, top up with coolant that has
been tested and approved by Mercedes-
Benz.XReplace cap : and turn it clockwise as far
as it will go.
For further information on coolant, see
( Y page 341).
Topping up the windscreen washer sys-
tem/headlamp cleaning systemGWARNING
Windscreen washer concentrate is highly
flammable. If it comes into contact with hot
engine components or the exhaust system it
could ignite. There is a risk of fire and injury.
Make sure that no windscreen washer con-
centrate is spilled next to the filler neck.
Example
XTo open: pull cap : upwards by the tab.XTop up with the premixed washer fluid.XTo close: press cap : onto the filler neck
until it engages.
The washer fluid reservoir is used for both the
windscreen washer system and the headlamp
cleaning system.
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 refill the washer fluid
( Y page 254).
Further information on windscreen washer
fluid/antifreeze ( Y page 342).
Service
ASSYST PLUS
Service messages
The ASSYST PLUS service interval display
informs you of the next service due date.
286ServiceMaintenance and care
ProCarManuals.com
The highly flammable gas mixture is created
while the battery is charging and when jump-
starting.
Always make sure that neither you nor the
battery is electrostatically charged. Electro-
static charge is created, for example:
R by wearing synthetic fibre clothing
R due to friction between clothing and the
seat
R when you pull or push the battery across
carpet or other synthetic materials
R when you rub the battery with a clothGWARNING
During the charging process, a battery produ-
ces 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 con-
tact with vehicle parts.
R Never place metal objects or tools on a bat-
tery.
R It is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
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 jump leads.
R Never connect or disconnect the battery
terminals while the engine is running.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with the skin, eyes or clothing.
Do not inhale any battery gases. Do not lean
over the battery. Keep children away from
batteries. Wash battery acid immediately with
water and seek medical attention.
HEnvironmental noteBatteries contain pollutants.
It is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in an
environmentally responsible
recycling system.Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-
lection point for used batter-
ies.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Service
Booklet or contact a qualified specialist
workshop for more information.
! Always have work on the battery carried
out at a qualified specialist workshop.
Should it, in exceptional circumstances, be
absolutely necessary to disconnect the bat-
tery yourself, please observe the following:
R switch off the engine and remove the
key. Check that all the indicator lamps in
the instrument cluster are off. Otherwise,
you may damage electronic components
such as the alternator, for example.
R first, disconnect the negative terminal
clamp, followed by the positive terminal
clamp. Never swap the terminal clamps.
The vehicle electronics may otherwise be
damaged.
R on vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The vehi-
cle is secured against rolling away. You
can then no longer move the vehicle.
The battery and the cover of the positive
terminal clamp must be fitted securely dur-
ing operation.
Battery (vehicle)303Breakdown assistanceZProCarManuals.com
XDepress the clutch pedal fully and shift to
neutral.XRelease the brake pedal.XTow-start the vehicle.XDepress the clutch pedal fully and engage
second gear.XRelease the clutch pedal slowly without
depressing the accelerator pedal.
The engine is started.XDepress the clutch pedal fully and shift to
neutral.XStop at a suitable place.XSecure the vehicle by applying the electric
parking brake.XRemove the rigid towing bar or towing rope.XRemove the towing eye ( Y page 310).XSwitch off the hazard warning lamps.
When tow-starting, it is important that you
observe the safety notes (Y page 308) and the
legal requirements in each respective coun-
try.
Electrical fuses
Important safety notes
GWARNING
If you manipulate, bridge or replace a faulty
fuse with a fuse of a higher amperage, the
electric cables could be overloaded. This may
result in a fire. There is a risk of an accident
and injury.
Always replace faulty fuses with specified new
fuses of the correct amperage.
! Only use fuses that have been approved
for Mercedes-Benz vehicles and which
have the correct fuse rating for the system
concerned. Only use fuses marked with an
"S". Components or systems could other-
wise be damaged.
The fuses in your vehicle serve to disconnect
faulty circuits. If a fuse blows, all the compo-
nents on the circuit and their functions will
fail.
Blown fuses must be replaced with fuses of
the same rating, which you can recognise by
the colour and fuse rating. The fuse ratings
are listed in the fuse allocation chart.
If the newly inserted fuse also blows, have the
cause traced and rectified at a qualified spe-
cialist workshop, e.g. a Mercedes-Benz
Service Centre.
Before replacing a fuse
XSecure the vehicle against rolling away
( Y page 162).XSwitch off all electrical consumers.XTurn the key to position 0 in the ignition
lock and remove it ( Y page 145). All indi-
cator lamps in the instrument cluster must
be off.
The fuses are located in various fuse boxes:
R fuse box in the engine compartment on the
left-hand side of the vehicle, when viewed
in the direction of travel
R fuse box in the front-passenger footwell
The fuse allocation chart is on the fuse box in
the front-passenger footwell ( Y page 313).
Fuse box in the engine compartment
GWARNING
When the bonnet is open, and the windscreen
wipers are set in motion, you can be injured
by the wiper linkage. There is a risk of injury.
Always switch off the windscreen wipers and
the ignition before opening the bonnet.
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses.
312Electrical fusesBreakdown assistance
ProCarManuals.com
If you wish to confirm the restart:XPress the a button.
The Tyre press. now OK? message
appears in the multifunction display.XPress the 9 or : button to select
Yes .XPress the a button.
The Run Flat Indicator restarted
message appears in the multifunction dis-
play.
After a teach-in period, the tyre pressure
loss warning system will monitor the set
tyre pressures of all four tyres.
If you wish to cancel the restart:
XPress the % button.
or
XWhen the Tyre press. now OK? message
appears, press the 9 or : button to
select Cancel .XPress the a button.
The tyre pressure values stored at the last
restart will continue to be monitored.
Tyre pressure monitor
General notes
If a tyre pressure monitor system is fitted, the
vehicle's wheels have sensors fitted that
monitor the tyre pressures in all four tyres.
The tyre pressure monitor warns you if the
pressure drops in one or more of the tyres.
The tyre pressure monitor only functions if
the corresponding sensors are fitted to all
wheels.
Information on tyre pressures is shown in the
multifunction display. After a few minutes of
driving, the current tyre pressure of each tyre
is shown in the Service menu of the multi-
function display. For further information on
displaying this message, refer to the "Check-
ing the tyre pressure electronically" section
( Y page 323).
Important safety notes
It is the driver's responsibility to set the tyre
pressure to the recommended cold tyre pres-
sure suitable for the operating situation
( Y page 319). Note that the correct tyre pres-
sure for the current operating situation must
first be taught-in to the tyre pressure monitor.
If there is a substantial loss of pressure, the
warning threshold for the warning message is
aligned to the reference values taught-in.
Restart the tyre pressure monitor after
adjusting to the cold tyre pressure
( Y page 324). The current pressures are
saved as new reference values. This will
ensure that a warning message will only
appear if the tyre pressure drops significantly.
The tyre pressure monitor does not warn you
of an incorrectly set tyre pressure. Observe
the notes on the recommended tyre pressure
( Y page 319).
The tyre pressure monitor is not able to warn
you of a sudden loss of pressure, e.g. if the
tyre is penetrated by a foreign object. In the
event of a sudden loss of pressure, bring the
vehicle to a halt by braking carefully. Avoid
abrupt steering manoeuvres.
The tyre pressure monitor has a yellow warn-
ing lamp in the instrument cluster for indicat-
ing a pressure loss or malfunction. Depending
on how the warning lamp flashes or lights up,
a tyre pressure that is too low or a malfunc-
tion in the tyre pressure monitor is indicated:
R if the warning lamp is lit continuously, the
tyre pressure on one or more tyres is sig-
nificantly too low. The tyre pressure moni-
tor is not malfunctioning.
R if the warning lamp flashes for around a
minute and then remains lit constantly, the
tyre pressure monitor is malfunctioning.
i In addition to the warning lamp, a mes-
sage appears in the multifunction display.
Further information can be found on
( Y page 248).
If the tyre pressure monitor is malfunctioning,
it may take more than ten minutes for the tyre
322Tyre pressureWheels and tyres
ProCarManuals.com