
Diesel Exhaust Fluid(DEF)
Vehicles wit hpassenger vehicle approva l
Display messagesPossible causes/consequences an dMSolutions
dEF ChkIn addition ,th eyello wå DEFindicator lamp lights up in th einstru-
men tcluster and awarnin gtone sounds.
The DE Fsupply has dropped belo w1.5US gal (5.5l).
XAdd DEF supply (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.
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.
In addition, the yellow ;Check Engine indicator lamp and the yel-
low å DEF indicator lamp light up in the instrument cluster and
three short warning tones sound.
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.
Display messages177
On-board computer and displays
Z

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

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

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

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