ProblemPossible causes/consequences andMSolutions
d
The yellow
ASR/ESP®warn-
ing lamp is lit
while the engine
is running.
The all-wheel drive is activated/deactivated. When changing gear,
ASR and ESP®are deactivated.
After changing gear, ASR and ESP®are automatically reactivated.
Engage/disengage the all-wheel drive (
Ypage 147).
d The yellow
ASR/ESP®warn-
ing lamp flashes
slowly while the
vehicle is in
motion.
In vehicles with all-wheel drive the brake system is overheated.
GWARNING
The performance of 4ETS is reduced. The braking power output may
be lower.
There is a risk of an accident.
XDrive on carefully and adapt your driving style to suit the road and
traffic conditions.
XWhen the message is no longer displayed, 4ETS and normal braking
power are available again.
d The yellow
ASR/ESP®warn-
ing lamp is lit
while the engine
is running.
ASR is deactivated.
GWARNING
The driven wheels can spin when accelerating.
There is an increased risk of skidding and accidents.
XActivate ASR again. Exceptions (Ypage 55).
h !:b
The yellow ESP®, ABS
and ASR/BAS indicator
lamps and the red brake
system indicator lamp
are lit while the engine is
running.
EBD is malfunctioning or deactivated due to undervoltage or malfunc-
tion.
The battery may not be being charged.
GWARNING
The rear wheels could lock sooner than expected when you apply the
brakes. The braking distance can increase in emergency braking sit-
uations.
There is an increased risk of skidding and accidents.
XVehicles with steering wheel buttons: also observe the messages in
the display (Ypage 181).
XStop the vehicle as soon as possible, paying attention to road and
traffic conditions.
XDo not drive on.
XConsult a qualified specialist workshop.
196Indicator and warning lamps in the instrument cluster
On-board computer and displays
ProblemPossible causes/consequences andMSolutions
b
The red brake sys-
tem indicator
lamp is lit while
the engine is run-
ning.There is insufficient brake fluid in the expansion tank.
GWARNING
Braking performance can be impaired.
There is a risk of an accident.
XVehicles with steering wheel buttons: also observe the messages in
the display (Ypage 181).
XStop the vehicle as soon as possible, paying attention to road and
traffic conditions.
XCheck the brake fluid level in the expansion tank (Ypage 224).
XIf the brake fluid is below the MIN mark: do not drive on!
XDo not add brake fluid. This does not solve the problem.
XConsult a qualified specialist workshop.
b When towing a
trailer: the red
brake system
indicator lamp is
lit while the
engine is running.
Additionally, a
warning tone
sounds.GWARNING
The brake force booster in the trailer is faulty.
The driving and braking characteristics of your vehicle could change.
There is a risk of the trailer overbraking and of you losing control over
the truck/trailer combination.
There is a risk of an accident.
XVehicles with steering wheel buttons: also observe the messages in
the display (Ypage 181).
XStop the vehicle as soon as possible, paying attention to road and
traffic conditions.
XDo not drive on.
XConsult a qualified specialist workshop.
: The yellow
ASR/BAS indica-
tor lamp is lit
while the engine
is running.ASR has been deactivated due to a malfunction.
The engine power output may be reduced.
GWARNING
The driven wheels can spin when accelerating.
There is an increased risk of skidding and accidents.
XDrive on with care.
XConsult a qualified specialist workshop as soon as possible.
: The yellow
ASR/BAS indica-
tor lamp is lit
while the engine
is running.BAS has been deactivated due to a malfunction.
GWARNING
The brake system continues to function normally, but without elec-
tronic support.
The braking distance can increase in emergency braking situations.
There is a risk of an accident.
XDrive on with care.
XVisit a qualified specialist workshop immediately.
Indicator and warning lamps in the instrument cluster197
On-board computer and displays
Z
ProblemPossible causes/consequences andMSolutions
:
The yellow
ASR/BAS indica-
tor lamp is lit
while the engine
is running.ASR and BAS have been deactivated due to undervoltage.
The battery may not be being charged.
GWARNING
The brake system is still available with the normal braking effect.
The driven wheels can spin when accelerating.
The braking distance can increase in emergency braking situations.
There is an increased risk of skidding and accidents.
XDrive on with care.
XVisit a qualified specialist workshop immediately.
! The yellow ABS
indicator lamp is
lit while the
engine is running.ABS is deactivated due to a malfunction or is temporarily unavailable.
ESP®, ASR and BAS, as well as cruise control, are also unavailable as
a result.
Self-diagnosis may not be complete, or the battery may not be charg-
ing.
GWARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock, e.g. if the
brakes are applied with maximum force.
This causes steerability and braking to be greatly impaired.
The braking distance can increase in emergency braking situations.
The driven wheels can spin when accelerating.
If ESP
®is not operational, ESP®will not stabilize the vehicle.
There is an increased risk of skidding and accidents.
XDrive a short distance at a speed above 13 mph (20 km/h).
The functions mentioned above are available again when the indi-
cator lamp goes out.
If the indicator lamp does not go out:
XDrive on with care.
XVisit a qualified specialist workshop immediately.
å The yellow DEF
indicator lamp is
lit while the
engine is running.The exhaust gas aftertreatment is malfunctioning or the current Diesel
Exhaust Fluid (DEF) supply is limiting the range.
XObserve the messages in the display.
198Indicator and warning lamps in the instrument cluster
On-board computer and displays
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 181).
XDrive on with care.
XVisit a qualified specialist workshop immediately.
6 The red warning
lamp does not go
out approx-
imately four sec-
onds 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.
Indicator and warning lamps in the instrument cluster199
On-board computer and displays
Z
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 222).
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 222).
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
starting the
engine 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 222).
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 223).
XIf you need to add coolant frequently, have the engine cooling sys-
tem checked at a qualified specialist workshop.
200Indicator and warning lamps in the instrument cluster
On-board computer and displays
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.
XLet the engine run at idling speed for approximately one minute.
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 126).
XBleed the fuel system (Ypage 122).
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.
Indicator and warning lamps in the instrument cluster201
On-board computer and displays
Z
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 key
to position 2in
the ignition lock,
the yellow pre-
glow indicator
lamp remains lit
for approximately
one minute. Or
the yellow pre-
glow indicator
lamp lights up for
approximately
one 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 193).
202Indicator and warning lamps in the instrument cluster
On-board computer and displays
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 225).
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 225).
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 44).
bWhen the key is
turned to position
2in the ignition
lock, the yellow
bulb warning
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 89).
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.
Indicator and warning lamps in the instrument cluster203
On-board computer and displays
Z