Display messagesPossible causes/consequences andMSolutions
Highbeam AssistinoperativeHighbeamAssis tis faulty.
XVisit aqualified specialist workshop .
HighbeamAssisttem‐porarily unavaila‐ble
Highbea mAssis tis deactivated and temporarily inoperative.
Possibl ecauses are:
RThe camera' sfunctionalit yis impaire ddue to heav yrain ,snow or
fog .
RThe windshield is dirty in th ecamera' sfield of vision .
XStop thevehicl epayin gattention to roa dand traffic conditions.
XSecur eth evehicl eto preven tit from rollin gaway (Ypage 127).
XClean th ewindshield (Ypage 231), particularly in th ecamera' s
field of vision .
If th emalfunction has been rectified, th eHighbeam Assist
available againmessage appears.
Engine
Display messagesPossible causes/consequences and MSolutions
Check DieselExhaustFluid SeeOperator' sManual
The DE Fsupply has dropped belo w1.5US gal (5. 5l).
XAd dDE Fsupply (Ypage 126).
The display message only disappear swhen th evehicl eis stationary,
at th elatest after 20 seconds, as soo nas you switch on th eignition
or start th eengin eafter refueling.
å
XX starts remaining
Three short warning tone salso sound.
Afte rth emessage appear sfor th efirst time, th eremaining DE Fsupply
will last for approximately 1200 mile s(1900 km). The engin ecan then
only be started another 16 times .
The number of remaining engin estart sxx
(16to 0)is shown in th e
message every time th eengin eis started.
XAd dat least 1. 5US gal (5.5l)of DEF (Ypage 126).
å
Idle Mode
The yellow ;Check Engine indicator lamp also lights up and three
short warning tones sound.
You cannot drive the vehicle at a speed exceeding 5 mph (8 km/h).
XAdd at least 1.5 US gal (5.5 l)of DEF (Ypage 126).
The display message and the yellow ;Check Engine indicator
lamp only disappear when the vehicle is stationary, at the latest
after 20 seconds as soon as you switch on the ignition or start the
engine after refueling.
Check DieselExhaust Fluid SeeOperator's Manual
In addition, the yellow ;DEF indicator lamp lights up and a warning
tone sounds.
The DEF reducing agent is contaminated, diluted or is not compliant
with ISO 22241.
XHave the DEF tank cleaned and refilled at a qualified specialist
workshop as soon as possible.
184Display messages
On-board computer and displays
Display messagesPossible causes/consequences andMSolutions
å
XX starts remaining
The yellow; CheckEngin eindicator lamp also lights up and three
short warning tone ssound.
Afte rth emessage appear sfor th efirst time, th eremaining DE Fsupply
will last for approximately 1200 mile s(1900 km). The engin ecan then
only be started another 16 times .
The number of remaining engin estart sxx
(16to 0)is shown in th e
message every time th eengin eis started.
The DE Freducin gagen tis contaminated, diluted or is no tcomplian t
wit hIS O 22241.
The exhaust gas aftertreatmen tis malfunctioning or an emission rel -
evan tmalfunction has occurred .This malfunction or defec tcan dam-
age th eexhaust gas aftertreatment.
XVisit aqualified specialist workshop immediately.
å
Idl eMod e
The yello w; CheckEngin eindicator lamp also lights up and three
short warning tone ssound.
The vehicl ecanno tbe driven at aspeed exceedin g 5mph (8 km/h).
XVisit aqualified specialist workshop immediately.
?
Coolan tStop, tur nengine off
The coolanttemperature is to ohigh .
If th evehicl eis stoppe dafter bein gsubjecte dto extreme loads ,th e
coolan twarning lamp may come on when th eignition is switched on
or th eengin eis restarted. Suc hloads can be, for example, drivin gin
mountainous terrain or drivin gwit h a trailer .
XRun th eengin efor approximately 1minute at idlin gspeed.
XConsult aqualified specialist workshop if th edisplay message con-
tinue sto be shown.
*
Check coolan tlevel
The coolan tlevel is to olow.
Never run th eengin eif th ecoolan tlevel is to olow. The engin ecould
overheat and be damaged.
XStop th evehicl eas soo nas possible, payin gattention to roa dand
traffic conditions.
XSwitc hoff th eengin eand let it cool down .
XAddcoolan tand be sur eto observ eth ewarning note s
(Ypage 280).
XIf you need to add coolan tfrequently, hav eth eengin ecoolin gsys-
te m checke dat aqualified specialist workshop .
7
Reservefue lDriveto agas statio n
The fuel level has fallen int oth ereserv erange.
XRefue lat th eneares tgas station (Ypage 124).
:
WaterinfuelVisitworkshop
The water that has collecte din th ewater separator has reached th e
maximum level.
XDrain th ewater separator (Ypage 220).
Display messages185
On-board computer and displays
Z
ProblemPossible causes/consequences andMSolutions
h
The yellow ESP®
indicator lamp is
lit while the
engine is running.ESP®is deactivated due to undervoltage or a malfunction. As a result,
cruise control has also been deactivated.
Engine power output may be reduced.
The battery may not be being charged.
GWARNING
If ESP
®is not operational, ESP®will not stabilize the vehicle.
There is an increased risk of skidding and accidents.
XVehicles with steering wheel buttons: also observe the messages in the display (Ypage 173).
XDrive on with care.
XVisit a qualified specialist workshop immediately.
6 The red warning
lamp does not go
out approx-
imately 4 seconds
after the ignition
is switched on, or
it lights up again.The restraint systems have malfunctioned.
GWARNING
If the restraint systems are malfunctioning, individual systems could
be triggered inadvertently or might not be triggered at all in the event
of an accident.
There is an increased risk of injury and accidents.
XDrive on with care.
XVisit a qualified specialist workshop immediately.
# The red battery
indicator lamp is
lit while the
engine is running.The battery is not being charged. Possible causes are a defective
alternator or a torn poly-V-belt.
XStop the vehicle as soon as possible, paying attention to road and
traffic conditions.
XCheck the poly-V-belt.
XIf the poly-V-belt is torn: do not continue driving. Consult the near-
est qualified specialist workshop.
XIf the poly-V-belt is not damaged: have the vehicle checked as soon
as possible by a qualified specialist workshop.
#The red battery
indicator lamp is
lit while the
engine is running.The battery is faulty.
XStop the vehicle as soon as possible, paying attention to road and
traffic conditions.
XDo not continue driving under any circumstances.
XConsult a qualified specialist workshop.
#The yellow brake
pad wear indica-
tor lamp is lit after
the engine is star-
ted or while the
vehicle is in
motion.The brake pads/linings have reached their wear limit.
GWARNING
Braking performance can be impaired.
There is a risk of an accident.
XHave the brake pads/linings replaced as soon as possible at a
qualified specialist workshop.
194Indicator and warning lamps in the instrument cluster
On-board computer and displays
ProblemPossible causes/consequences andMSolutions
4
The yellow engine
oil level warning
lamp lights up
after the engine is
started or while
the vehicle is in
motion.The oil level has dropped to the minimum level.
XCheck the engine for oil loss.
XIf oil loss is detected: consult a qualified specialist workshop imme-
diately.
XIf no oil loss is detected: check the oil level and add engine oil
(Ypage 217).
4 The yellow warn-
ing lamp flashes
and the warning
buzzer sounds
after the engine is
started or while
the vehicle is in
motion.On vehicles with a diesel engine, the oil level display additionally
appears in the display, e.g. – 2.0 qts(Canada:– 2.0 ltr).
There is not enough or no oil in the engine.
There is a danger of engine damage.
XStop the vehicle as soon as possible, paying attention to road and
traffic conditions.
XCheck the oil level with the oil dipstick (Ypage 217).
XIf the engine oil level is correct: have the malfunction rectified
immediately at a qualified specialist workshop.
XIf the engine oil level is too low: have the vehicle towed to a qualified
specialist workshop.
4 The yellow engine
oil level warning
lamp lights up and
the warning buz-
zer sounds after
the engine is star-
ted or while the
vehicle is in
motion.The engine oil level is above the maximum level.
There is a risk of damaging the engine or catalytic converter.
XCheck the oil level with the oil dipstick (Ypage 217).
XIf the oil level is too high: have the engine oil extracted as soon as
possible at a qualified specialist workshop.
XIf the oil level is correct: have the malfunction rectified as soon as
possible at a qualified specialist workshop.
4 On vehicles with a
diesel engine, the
yellow warning
lamp lights up
repeatedly during
the journey.There is a malfunction in the engine oil level display.
XHave the vehicle checked immediately at a qualified specialist
workshop.
%The yellow cool-
ant level warning
lamp lights up
while the engine
is running.The coolant level is too low.
Never run the engine if the coolant level is too low. The engine could
overheat and be damaged.
XStop the vehicle as soon as possible, paying attention to road and
traffic conditions.
XSwitch off the engine and let it cool down.
XAdd coolant and be sure to observe the warning notes
(Ypage 218).
XIf you need to add coolant frequently, have the engine cooling sys-
tem checked at a qualified specialist workshop.
Indicator and warning lamps in the instrument cluster195
On-board computer and displays
Z
ProblemPossible causes/consequences andMSolutions
?
The red coolant
warning lamp is lit
while the engine
is running.The coolant temperature is too high.
XStop the vehicle as soon as possible, paying attention to road and
traffic conditions.
XConsult a qualified specialist workshop.
?The red coolant
warning lamp is lit
while the engine
is running.The coolant temperature is too high.
If the vehicle is stopped after being subjected to extreme loads, the
coolant warning lamp may come on when the ignition is switched on
or the engine is restarted. Such loads can be, for example, driving in
mountainous terrain or driving with a trailer.
XRun the engine for approximately 1 minute at idling speed.
XConsult a qualified specialist workshop if the display message con-
tinues to be shown.
7
|The yellow
reserve fuel warn-
ing lamp is on. At
the same time,
0
appears in the
fuel tank content
display while the
engine is running,
although there is
fuel in the fuel
tank.
The fuel filler cap is not closed.
XClose the fuel filler cap.
You will hear a click when the fuel filler cap is closed fully.
XIf the malfunction continues to be displayed, have it rectified imme-
diately at a qualified specialist workshop.
;
The yellow Check
Engine indicator
lamp is lit up or
flashes while the
engine is running.You have used up all fuel in the tank.
The engine is running in emergency mode.
XRefuel at the nearest gas station (Ypage 124).
XBleed the fuel system (Ypage 120).
XStart the engine three to four times in succession after refueling.
Emergency running mode will be canceled. The vehicle does not
need to be checked.
;The yellow Check
Engine indicator
lamp is lit up or
flashes while the
engine is running.The injection control is malfunctioning.
The engine is running in emergency mode.
Engine power output may be reduced.
XHave the vehicle checked at a qualified specialist workshop as soon
as possible.
In some states it is legally prescribed that after the Check Engine
indicator lamp lights up you must contact a qualified specialist work-
shop immediately. Observe the legal requirements.
196Indicator and warning lamps in the instrument cluster
On-board computer and displays
ProblemPossible causes/consequences andMSolutions
;
The yellow Check
Engine indicator
lamp is lit while
the engine is run-
ning.The exhaust gas aftertreatment is malfunctioning or an emission rel-
evant malfunction has occurred. This malfunction or defect can dam-
age the exhaust gas aftertreatment.
After the first message and under normal operating conditions, you
can drive on for up to approximately 500 mi (800 km). Then a warning
tone sequence sounds and the engine can only be started another 16
times.
XObserve the messages in the display.
XHave the exhaust gas aftertreatment checked immediately at a
qualified specialist workshop.
In some states it is legally prescribed that after the Check Engine
indicator lamp lights up you must contact a qualified specialist work-
shop immediately. Observe the legal requirements.
% If you turn the
SmartKey to posi-
tion2in the igni-
tion lock, the yel-
low preglow indi-
cator lamp
remains lit for
approximately
1 minute. Or the
yellow preglow
indicator lamp
lights up for
approximately
1 minute while
the engine is run-
ning.At extremely low temperatures, the engine may not start.
There is a malfunction in the preglow system.
XHave any malfunction rectified at a qualified specialist workshop.
È The yellow air fil-
ter indicator lamp
is lit while the
engine is running.The service limit for the air filter has been reached. The air filter is dirty.
XHave the air filter element replaced as soon as possible at a quali-
fied specialist workshop.
hThe yellow tire
pressure monitor
warning lamp
comes on.GWARNING
The tire pressure monitor indicates a rapid or severe loss of pressure
in at least one tire.
XStop the vehicle without making any extreme steering maneuvers or
braking suddenly. Pay attention to the traffic conditions while doing
so.
XCheck the tires and correct the tire pressure. If a tire continues to
lose pressure, it must be replaced. Replace damaged tires imme-
diately.
The warning light will go out after the flat tire has been rectified and
you have been driving for a few minutes.
XVehicles with steering wheel buttons: also observe the messages in the display (Ypage 173).
Indicator and warning lamps in the instrument cluster197
On-board computer and displays
Z
ProblemPossible causes/consequences andMSolutions
h
US vehicles only:
The yellow tire
pressure monitor
warning lamp
flashes for
60 seconds and
then remains lit.The tire pressure monitor has malfunctioned.
XHave the tire pressure monitor and the wheels checked at a quali-
fied specialist workshop.
:
The yellow water
separator indica-
tor lamp is lit
when the ignition
is switched on.The water that has collected in the water separator of the fuel filter has
reached the maximum level.
XDrain the water separator (Ypage 220).
m
The yellow water
separator indica-
tor lamp is lit
when the ignition
is switched on.The fuel filter is dirty.
XHave the fuel filter element replaced as soon as possible at a quali-
fied specialist workshop.
¦The yellow
washer fluid level
indicator lamp for
the windshield
washer/head-
lamp cleaning
system is lit after
the engine is star-
ted or while the
vehicle is in
motion.The water level is too low.
XAdd washer fluid (Ypage 220).
7The red seat belt
warning lamp
lights up continu-
ously or flashes. A
warning tone may
also sound.The warning lamp is to remind you to fasten your seat belt.
XFasten seat belt (Ypage 43).
bWhen the Smart-
Key is turned to
position 2in the
ignition lock, the
yellow bulb warn-
ing lamp lights up.One of the exterior lighting bulbs is faulty, with the exception of the
perimeter lamps and the trailer lighting.
iDepending on the equipment, the bulb failure indicator can fail for
all lamps with the exception of the turn signal lamps.
XReplace the faulty bulb as soon as possible (Ypage 87).
1 The yellow "door
open" indicator
lamp is lit while
driving.The vehicle is moving without all doors or the hood being closed.
XClose the doors or hood.
198Indicator and warning lamps in the instrument cluster
On-board computer and displays
Checking the brake fluid level
XStop your vehicle as far away from traffic as
possible on level ground.
XSwitch off the engine.
XSecure the vehicle to prevent it from rolling
away.
XOpen the hood (Ypage 214).
XCheck the brake fluid level.
The brake fluid level is correct if the level is
between the MIN mark and MAX mark on
brake fluid reservoir:.
XClose the hood.
!If the brake fluid level in the brake fluid res-
ervoir has fallen to the MIN mark or below,
check the brake system immediately for
leaks. Also check the thickness of the brake
linings. Visit a qualified specialist workshop
immediately.
Do not add brake fluid. This does not correct
the malfunction.
Washer fluid
GWARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
!Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or MB WinterFit. Unsuitable washer fluid could dam-
age the plastic lenses of the headlamps.
Example: washer fluid reservoir
Add windshield washer concentrate to the
washer fluid all year round. Observe the infor-
mation on washer fluid in the "Technical data"
section (
Ypage 281).
Adding washer fluid
XMix the washer fluid to the appropriate mixing ratio in a container beforehand.
XOpen the hood (Ypage 214).
XPull cap :on the washer fluid reservoir
upwards at the tab.
XAdd the premixed washer fluid.
XPress cap :onto the filler neck until it
engages audibly.
XClose the hood.
Fuel system
Draining the fuel filter
GWARNING
Fuel is highly flammable. Improper handling of
fuel creates a risk of fire and explosion.
Avoid fire, open flames, smoking and creating
sparks under all circumstances. Switch off the
ignition and auxiliary heating before carrying
out work to the fuel system. Always wear pro-
tective gloves.
HEnvironmental note
Dispose of the water-fuel mixture in an envi-
ronmentally responsible manner.
!When the :indicator lamp lights up,
drain the fuel filter with water separator
immediately. Otherwise, the engine may be
damaged.
220Engine compartment
Maintenance and care