Engine
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ;
N
The yellow engine diagnostics 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
R in the fuel system
The emission limit values may be exceeded and the engine may be running in emergency mode.
X Have the vehicle checked as soon as possible at a qualified specialist work-
shop. 8
N
The yellow reserve fuel warning lamp is on while the engine is running.
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. ?
N
The red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the bar display.
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 traffic condi-
tions, and switch off the engine. Do not continue driving under any circum-
stances.
X Secure the vehicle against rolling away (Y page 178).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
307On-board computer and displays Z
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ?
N
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.
X Observe the additional display messages in the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic condi-
tions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 178).
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 340).
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 125 †.
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. ?
N
The red coolant warning lamp comes on while the engine is running. A
warning tone also sounds.
The coolant temperature has exceeded 124 †. The airflow to the engine radi- ator 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 overhea-
ted can cause some fluids which may have leaked into the engine compart-
ment 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 traffic condi-
tions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 178).308
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Warning/
indicator
lamp
N N
Signal type
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 340).
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 At coolant temperatures below 125 †, drive to the nearest qualified spe-
cialist 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
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ·
N
The red distance warning 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. ·
N
The red distance warning 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.
Further information on PRE ‑SAFE®
Brake (Y page 77).
For further information about the distance warning function of COLLISION
PREVENTION ASSIST PLUS, see (Y page 73). Warning and indicator lamps in the instrument cluster
309On-board computer and displays Z
Tyres
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions h
N
The yellow tyre pressure 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.
G WARNING
Underinflated tyres pose the following risks:
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.
X Stop the vehicle without making any sudden steering or braking manoeu-
vres. Pay attention to the traffic conditions as you do so.
X Secure the vehicle to prevent it from rolling away (Y page 178).
X Observe the additional display messages in the multifunction display.
X Check the tyres and, if necessary, follow the instructions for a flat tyre
(Y page 356).
X Check the tyre pressure (Y page 381).
X If necessary, correct the tyre pressure. h
N
The yellow tyre pressure monitor warning lamp (pressure loss/malfunction)
flashes for approximately one minute and then remains lit.
The tyre pressure monitor is faulty.
G WARNING
The system is possibly unable to detect or register low tyre pressure.
There is a risk of an accident.
X Observe the additional display messages in the multifunction display.
X Visit a qualified specialist workshop. 310
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Vehicle
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions Ð
N
The red power steering warning lamp is lit while the engine is running.
The power steering assistance is faulty.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident. X Check whether you are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified specialist
workshop.
X If you are unable to steer safely: do not drive on. Contact the nearest
qualified specialist workshop. Warning and indicator lamps in the instrument cluster
311On-board computer and displays Z
be scalded by hot coolant spraying out when
opening the cap. There is a danger of injury.
Allow the engine to cool before opening the
cap. Wear gloves and protective eyewear
when opening. Slowly turn the cap half a turn to allow pressure to escape. 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 159).
or
X Press the Start/Stop button twice
(Y page 159).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
70 †.
X Turn the key to position 0in the ignition
lock (Y page 159).
or
X Remove the Start/Stop button from the
ignition lock (Y page 159).
X Slowly turn cap :half a turn anti-clock-
wise 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 ;.
If the coolant level is approximately 1.5 cm above marker bar =in the filler neck when warm, 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 406).
Topping up the windscreen washer sys-
tem 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 Place cap :on the edge of the filler neck
and engage in place. Engine compartment
341Maintenance and care Z
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
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 cloth G
WARNING
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. G
WARNING
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. H
Environmental note Batteries 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 batteries carried
out at a qualified specialist workshop.
Should it, in exceptional circumstances, be absolutely necessary to disconnect the 12-
volt battery yourself, please observe the
following:
R secure the vehicle to prevent it from roll-
ing away.
R switch off the engine and remove the
key. Make sure the ignition is switched
off. 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 the transmission is locked in position P
after disconnecting the battery. The vehi- Battery (vehicle)
361Breakdown assistance Z
Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged,
the engine can be jump-started from another vehicle or from a second battery using jump
leads. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or a jump-starting device.
R You may only jump-start the vehicle when the engine and exhaust system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may only be performed using batteries with a nominal voltage of 12 V.
R Only use jump leads that have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start. This charges the empty battery a little.
R Make sure that the two vehicles do not touch.
Make sure that:
R The jump leads are not damaged.
R Non-insulated parts of the terminal clamps do not come into contact with other metal parts
while the jump leads are connected to the battery.
R The jump leads cannot come into contact with parts which can move when the engine is
running, such as the V-belt pulley or the fan.
X Secure the vehicle by applying the electric parking brake.
X Shift the transmission to position P.
X Make sure the ignition is switched off (Y page 159). All indicator lamps in the instrument
cluster must be off. When using the key, turn the key to position 0in the ignition lock and
remove it (Y page 159).
X Switch off all electrical consumers, e.g. rear window heating, lighting etc.
X Open the bonnet. Earth point cover (example: right-hand drive) Jump-starting
365Breakdown assistance Z