
Display messagesPossible causes/consequences andMSolutions
¯
StArtS IdLE
In addition,th eyellow åDEFindicator lamp and th e; Check
Engin eindicator lamp ligh tup in th einstrumen tcluste rand three
warning tone ssound.
If th eStArtS
IdL Emessage is displayed, you canno tdrive th evehicl e
at aspeed of mor ethan 5mph (8 km/ h).
XAdd at least 1.5 US gal (5.5 l) of DEF (Ypage 128).
The å DEF indicator lamp only disappears when the vehicle is
stationary, at the latest after 20 secondsa s soon as you switch on
the ignition or start the engine after refueling.
In addition, the yellow ;Check Engine indicator lamp and the yel-
low å DEF indicator lamp light up in the instrument cluster and a
warning tone sounds.
You cannot drive the vehicle at a speed exceeding 5 mph (8 km/h).
XVisit a qualified specialist workshop immediately.
Vehicles with commercial vehicle approval
Display messagesPossible causes/consequences and MSolutions
dEF ChkIn addition, the yellowåDEF indicator lamp lights up in the instru-
ment cluster and a warning tone sounds.
The DEF supply has dropped below 1.5 US gal (5.5 l).
XAdd DEF supply (Ypage 128). The
The å DEF indicator lamp only disappears when the vehicle is
stationary, at the latest after 20 secondsa s soon as you switch on
the ignition or start the engine after refueling.
In addition, the yellow ;Check Engine indicator lamp and the yel-
low å DEF indicator lamp light up in the instrument cluster 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.
StArtS RExxIn addition, the yellow åDEF indicator lamp lights up and a warning
tone sequence sounds.
The DEF supply has dropped below the 0.8 US gal (3.0 l) reserve mark.
After the message appears for the first time, the remaining DEF supply
will last for approximately 1200 miles (1900 km). The engine can then
only be started another 16 times.
The number of remaining engine starts XX
(16to1) is shown in the
message every time the engine is started.
XAdd at least 1.5 US gal (5.5 l) of DEF (Ypage 128).
The å DEF indicator lamp only disappears 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.
178Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
In addition,th eyellow ;CheckEngin eindicator lamp and th eyel-
low å DEFindicator lamp ligh tup in th einstrumen tcluste rand
three short warning tone ssound.
The DE Freducin gagen tis contaminated, diluted or is no tcomplian t
wit hIS O 2224 1.
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.
XVisit a qualified specialist workshop immediately.
¯
StArtS IdLE
In addition, the yellow åDEF indicator lamp and the ;Check
Engine indicator lamp light up in the instrument cluster and three
warning tones sound.
If the StArtS
IdLEmessage is displayed, you cannot drive the vehicle
at a speed of more than 5 mph (8 km/h).
XAdd at least 1.5 US gal (5.5 l) of DEF (Ypage 128).
The å DEF indicator lamp only disappears 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.
In addition, the yellow ;Check Engine indicator lamp and the yel-
low å DEF indicator lamp light up in the instrument cluster and a
warning tone sounds.
You cannot drive the vehicle at a speed exceeding 5 mph (8 km/h).
XVisit a qualified specialist workshop immediately.
Display messages179
On-board computer and displays
Z

Lights
Display messagesPossible causes/consequences andMSolutions
b
Low beam left
The left-hand low beam is faulty3.
XHalogen headlamps:replace the bulb as soon as possible
(Ypage 90).
XBi-Xenon headlamps: consult a qualified specialist workshop as
soon as possible.
b
Low beam right
The right-hand low-beam headlamp is faulty3.
XHalogen headlamps: replace the bulb as soon as possible
(Ypage 90).
XBi-Xenon headlamps: consult a qualified specialist workshop as
soon as possible.
b
Cornering lt. left
The left-hand cornering light is faulty.
XReplace the bulb as soon as possible (Ypage 90).
b
Cornering lt. right
The right-hand cornering light is faulty.
XReplace the bulb as soon as possible (Ypage 90).
b
Lights on auto‐matic. Remove key
The automatic headlamp feature is active: the light switch is in the
à position and you have forgotten to remove the key.
XRemove the key from the ignition lock.
b
Turn signal left
The left-hand turn signal is faulty.
XChange the bulb as soon as possible in the front (Ypage 91) or rear
(Ypage 92) indicator lamp.
b
Turn signal right
The right-hand turn signal is faulty.
XChange the bulb as soon as possible in the front (Ypage 91) or rear
(Ypage 92) turn signal lamp.
b
Brake lamp left
The left brake lamp is faulty3.
XReplace the bulb as soon as possible (Ypage 92).
b
Brake lamp right
The right brake lamp is faulty3.
XReplace the bulb as soon as possible (Ypage 92).
b
Third brake lamp
The additional brake lamp is faulty3. This display message will only
appear if all LEDs have failed.
XConsult a qualified specialized workshop as soon as possible.
b
High beam left
The left-hand high-beam headlamp is faulty3.
XReplace the bulb as soon as possible (Ypage 90).
3Depending on the equipment, the bulb-failure indicator may not befeatured for any lamps other than the turn
signals.
Display messages185
On-board computer and displays
Z

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 129).
XClean th ewindshield (Ypage 236), particularly in th ecamera' s
field of vision .
If th emalfunction has been rectified, th emessage Highbeam
Assist Available Againappears.
Engine
Diesel Exhaust Flui d(DEF)
Vehicles wit hpassenger vehicle approva l
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 128).
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 toppin gup.
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 128).
å
Idle Mode
The yellow ;engine diagnostic 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 128).
The display message and the yellow ;engine diagnostic indi-
cator 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 topping up.
Display messages187
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
Check DieselExhaustFluid seeOperator' sManual
In addition ,th eyellow ;enginediagnostic indicator lamp lights up
and awarning tone sounds.
The DE Freducin gagen tis contaminated, diluted or is no tcomplian t
wit hIS O 22241.
XHav eth eDE Ftan kcleane dand refilled at aqualified specialist
workshop as soo nas possible.
å
XX starts remaining
The yellow ;enginediagnostic indicator 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 yellow ;enginediagnostic indicator lamp also lights up and
three short warning tone ssound.
You canno tdrive th evehicl eat aspeed exceedin g 5mph (8 km/h).
XVisit aqualified specialist workshop immediately.
Vehicles wit hcommercial vehicle approva l
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 128).
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 toppin gup.
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 128).
188Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
å
IdleMod e
The yellow ;enginediagnostic indicator lamp also lights up and
three short warning tone ssound.
You canno tdrive th evehicl eat aspeed exceedin g 5mph (8 km/h).
XAddat least 1. 5US gal (5.5l)of DEF (Ypage 128).
The display message and the yellow ;engine diagnostic indi-
cator 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 topping up.
Check DieselExhaust Fluid seeOperator's Manual
In addition, the yellow ;engine diagnostic 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.
å
XX starts remaining
The yellow ;engine diagnostic indicator lamp also lights up and
three short warning tones sound.
After the message appears for the first time, the remaining DEF supply
will last for approximately 1200 miles (1900 km). The engine can then
only be started another 16 times.
The number of remaining engine starts xx
(16to0) is shown in the
message every time the engine is started.
The DEF reducing agent is contaminated, diluted or is not compliant
with ISO 22241.
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.
XVisit a qualified specialist workshop immediately.
å
Idle Mode
The yellow ;engine diagnostic 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).
XVisit a qualified specialist workshop immediately.
Display messages189
On-board computer and displays
Z

Engine
Display messagesPossible causes/consequences andMSolutions
?
Coolant Stop, turnengine off
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.
*
Coolant Check level
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 285).
XIf you need to add coolant frequently, have the engine cooling sys-
tem checked at a qualified specialist workshop.
7
Reserve fuel Driveto a filling stat.
The fuel level has fallen into the reserve range.
XRefuel at the nearest gas station (Ypage 126).
:
WaterinfuelVisitworkshop
The water that has collected in the water separator has reached the
maximum level.
XDrain the water separator (Ypage 225).
m
Fuel filter Visitworkshop
The fuel filter is dirty.
XHave the fuel filter element replaced as soon as possible at a quali-
fied specialist workshop.
4
Engine oil Add 1.0quart(Canada: 1.0liter)
The oil level is too low.
XCheck the oil level the next time you refuel (Ypage 221), and add
oil.
4
Engine oil levelNot when eng. run‐ning
You want to check the engine oil level even though the engine is still
running.
XSwitch off the engine.
XCheck the oil level (Ypage 221).
190Display messages
On-board computer and displays

Indicator and warning lamps in the instrument cluster
When switching on theignition ,som esystems carry out aself-test .Some indicator and warning
lamp smay temporarily tur non or start to flash. This is no tan indication of any problem .Only when
these indicator and warning lights tur non or start flashin gafter th eengin ehas started or during th e
journey has amalfunction occurred .
ProblemPossible causes/consequences and MSolutions
·
The red distanc e
warning lamp
lights up while th e
vehicl eis in
motion .The distanc eto th evehicl ein fron tis to osmall for th espee dselected.
Increase th edistance.
·
The red distanc e
warning lamp
flashes while th e
vehicl eis in
motion .Addition -
ally, an intermit -
tent warning tone
sounds.You are approachin g avehicl eahead at to ohigh aspeed.
XBe prepare dto brak eimmediately.
XPay particular attention to th etraffic situation .You may hav eto
brak eor tak eevasive action .
Ã
The yellow Lan e
Keepin gAssist
indicator lamp
lights up while
you are driving .LaneKeepin gAssist is deactivated.
XActivat eLan eKeepin gAssist if necessar y (Ypage 146).
Ã
The green Lan e
Keepin gAssist
indicator lamp
lights up while
you are driving .LaneKeepin gAssist is operational.
Ã
The red Lan e
Keepin gAssist
indicator lamp
lights up while
you are driving .
Additionally, an
intermittent
warning tone
sounds.You are driving wit hth efron twhee lon alan emarking.
d
The yellow
ASR/ESP®warn-
ing lamp flashes
while th evehicl e
is in motion .GWARNING
ES P
®or AS Ris intervening because at least on eof th ewheels has
reached it stire gri plimit.
Cruis econtrol is deactivated for th eduration of th eintervention .
XAdapt your driving style to suit th eroad and traffic conditions. Do
no tuse to omuc hthrottle.
XDrive slowly.
Indicator and warning lamps in the instrument cluster195
On-board computer and displays
Z