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
Drivingsystems
Display messagesPossible causes/consequences an dMSolutions
Errflashe sfo r 5 seconds, in addition th eà indicator lamp flashes in
th einstrumen tcluster and then lights up yello wcontinuously.
Lan eKeepin gAssis tis deactivated and temporarily inoperative .
Possible causes are :
RThere are no lanemarking spresent.
RThe camera's functionalit yis impaire ddue to heav yrain ,snow or
fog.
RThe camera canno trecogniz eth eroad markings:
-It is to odark.
-The lan emarking sare wor nor are covered, fo rexample, by dir tor
snow.
RThe windshield is dirty in th ecamera's field of vision .
XStop thevehicle payin gattention to road and traffic conditions.
XSecur eth evehicle to preven tit from rollin gaway (Ypage 129).
XClean th ewindshield (Ypage 236), particularly in th ecamera's
field of vision .
If th eà indicator lamp goe sout ,Lan eKeepin gAssis tis opera-
tional again .
If th eproblem persists ,visit aqualified specialis tworkshop .
Errflashesfo r 5 seconds ,th e_ indicator lamp also flashes and then
goe sout .
Highbeam Assis tis deactivated and temporarily no toperational or
Highbeam Assis tis malfunctioning.
Possible causes are :
RThe camera's functionalit yis impaire ddue to heav yrain ,snow or
fog.
RThe windshield is dirty in th ecamera's field of vision .
XStop thevehicle payin gattention to road and traffic conditions.
XSecur eth evehicle to preven tit from rollin gaway (Ypage 129).
XClean th ewindshield (Ypage 236), particularly in th ecamera's
field of vision .
If th e_ indicator lamp goe sout ,Highbeam Assis tis operational
again .
If th eproblem persists ,visit aqualified specialis tworkshop .
Blind_Errflashesfo r 5 seconds ,th eyello windicator lamp sflas hin th eexterio r
mirrors and then ligh tup constantly.
Blin dSpot Assis tis faulty.
XVisit aqualified specialis tworkshop .
Errflashesfo r 5 seconds ,th eÄ indicator lamp also flashes and then
lights up constantly.
COLLISION PREVENTION ASSIST is malfunctioning.
XVisit aqualified specialis tworkshop .
180Display messages
On-board computer and displays
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
b
Highbea mright
The right-hand high beam headlamp is fault y3.
XReplaceth ebulb as soo nas possibl e (Ypage 90).
b
Licenseplate lam p
Alicense plat elamp is faulty.3
XReplac eth ebulb as soo nas possibl e (Ypage 93).
b
Switch off lights
You haveforgotte nto switch off th elights when leaving th evehicle.
XTurn th eligh tswitch to $.
b
Foglampfront lef t
The left-han dfron tfog lamp is faulty.3
XHav eth ebulb replace das soo nas possibl eat aqualified specialist
workshop .
b
Foglampfront right
The right-hand fron tfog lamp is fault y3.
XHaveth ebulb replace das soo nas possibl eat aqualified specialist
workshop .
b
Rearfoglam p
The rear fog lamp is fault y3.
XReplaceth ebulb as soo nas possibl e (Ypage 92).
b
Parkinglam pfrontlef t
The left-han dfron tparking lamp/standin glamp is fault y3.
XReplaceth ebulb as soo nas possibl e (Ypage 91).
b
Parkinglam pfrontright
The right-hand fron tparking lamp/standin glamp is fault y3.
XReplaceth ebulb as soo nas possibl e (Ypage 91).
b
Reverselam p
Abackup lamp is fault y3.
XReplaceth ebulb as soo nas possibl e (Ypage 92).
b
Taillam plef t
The left-han dtai llamp is faulty.3
XReplac eth ebulb as soo nas possibl e (Ypage 92).
b
Taillam pright
The right-hand tai llamp is faulty.3
XReplac eth ebulb as soo nas possibl e (Ypage 92).
b
Marker lam p
Aperimete rlamp is fault y3.
XReplaceth ebulb as soo nas possibl e (Ypage 94).
3Dependin gon th eequipment, th ebulb-failure indicato rmay no tbe featured for any lamp sother than th etur n
signals.
186Display messages
On-board computer and displays
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