
Display messages
Possible causes/consequences and M
MSolutions
j Check trailer hitch lock *T
he trailer hitch is not operational. &
WARNING Risk of an accident if the ball neck is not loc ked
If th e ball neck is not in the loc ked position, the trailer may come loose. #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions.
Do not continue driving under any circums tances. #
Uncouple the trailer and secure it against rolling away. #
Initiate a new swivelling procedure and do not re-couple the trailer until the display message disappears. #
Stop theve hicle immediately, paying attention toroad and traf fic conditions, and switch off the engine. #
Uncouple the trailer and safeguard it against rolling away. #
Initiate a new swivelling procedure . #
When the display message disappears, couple up the trailer and drive on.
If th e display message does not disappear, the trailer hitch is defective and the ball neck is not loc ked. #
Do not couple up the trailer. Drive on without the trailer. Pay attention tothere duced ground clearance due to
th e unloc ked ball nec k. #
Consult a qualified specialist workshop.
Apply brake to deselect
Park (P) position *
Yo u ha veattem ptedto shift the transmission out of position jand into ano ther transmission position. #
Depress the brake pedal. Display messages and
warning/indicator lamps 449

Display messages
Possible causes/consequences and M
MSolutions
M *T
he engine bonnet is open. &
WARNING Risk of accident due todriving with the engine bonn etunlo cked
An unloc ked engine bonn etmay open up when theve hicle is in motion and block your vie w. #
Never unlock the engine bonn etwhen driving. #
Before every trip, ensure that the engine bonn etis loc ked. #
Pull over and stop theve hicle safely as soon as possible. #
Close the engine bonn et.
C *A
t least one door is open. #
Close all doors. 456
Displaymessa ges and warning/indicator lamps

Display messages
Possible causes/consequences and M
MSolutions
N *T
he boot lid is open. &
WARNING Risk ofexhaust gas poisoning
Combustion engines emit poisonous exhaust gases such as carbon monoxide. Exhaust gases can enter the
ve hicle interior if the boot lid is open when the engine is running, especially if theve hicle is in motion. #
Alw ays switch off the engine before opening the boot lid. #
Never drive with the boot lid open. #
Close the boot lid.
_ Example:Front left seat
backrest not locked *T
he seat backrest of the cor responding front seat is not engaged. #
Push the seat backrest back until it engages.
_
Example:Rear left seat
backrest not locked *T
he cor responding seat backrest of there ar ben chseat is not engaged. #
Foldthe cor responding seat backrest back until it engages. Display messages and
warning/indicator lamps 457

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
J Brake sy stem warning lamp The
red brake sy stem warning lamp is lit while the engine is running.
Po ssible causes:
R The brake forc e boosting is malfunctioning and the braking characteristics may be af fected.
R The reis insuf ficient brake fluid in the brake fluid reser voir. &
WARNING Thereis a risk of an accident if brake forc e boosting is malfunctioning
If brake forc e boosting is malfunctioning, the wheels may lock when braking. Braking characteristics may be
impaired. The braking dis tance may increase in an eme rgency braking situation. #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions. Do
not continue driving under any circums tances. #
Consult a qualified specialist workshop. &
WARNING Risk of an accident due tolow brake fluid le vel
If th e brake fluid le vel is too lo w,the braking ef fect and the braking characteristics may be impaired. #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions. Do
not continue driving under any circums tances. #
Consult a qualified specialist workshop.
Do not top up the brake fluid. Display messages and
warning/indicator lamps 465

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions #
Pull over and stop theve hicle safely as soon as possible, paying attention toroad and traf fic conditions. Do not
continue driving under any circums tances. #
Obser vethe messages in the multifunction displa y. #
Consult a qualified specialist workshop.
! ABS warning lamp The
yellow ABS warning lamp is lit while the engine is running.
ABS is malfunctioning.
If th ere is an additional acoustic warning signal, EBD is malfunctioning.
Other driving sy stems and driving saf ety sy stems may also be faulty. &
WARNING Thereisrisk of skidding if EBD or ABS is malfunctioning
If EBD or ABS is malfunctioning, the wheels could lock when braking
The steering capability and braking characteristics are thus se verely impaired. The braking dis tance may increase in
an emergency braking situation. In addition, other driving saf ety sy stems are switched off. #
Drive on carefull y. #
Have the brake sy stem checked immediately at a qualified specialist workshop. #
Drive on carefully. #
Obser vethe messages in the multifunction displa y. #
Consult a qualified specialist workshop. 466
Display messages and warning/indicator lamps

1,
2, 3 ...
12 V so cket
see Soc ket (12 V)
360° Camera ........................................... 201
Assigning as a favo urite ...................... .204
Care .................................................... 358
Fu nction .............................................. 201
Selecting a view .................................. 203 A
A/C function Activating/deactivating (control
panel) .................................................. 13 0
Ac tivating/deactivating (multimedia
sy stem) ................................................ 13 0
ABS (Anti-lock Braking Sy stem) ............ .167
Ac celeration
see Kickdown
Ac cess data
Editing ................................................ .314
Setting ................................................. 313
Ac oustic locking verification signal
Swit ching on/off .................................. .60Ac
tive Blind Spot Assi st.......................... 213
Ac tivating/deactivating ...................... .215
Brake application ................................. 213
Fu nction/no tes .................................... 213
Sy stem limits ....................................... 213
Tr ailer operation .................................. .213
Ac tive bonn et(pedestrian pr otection) .. 346
Operation ............................................ 346
Re setting ............................................. 346
Ac tive Brake Assi st.................................. 172
Fu nction/no tes .................................... 172
Setting ................................................. 176
Ac tive Eme rgency Stop Assist ...............189
Ac tive headlamps function .....................11 7
Ac tive Lane Change Assi st..................... 188
Ac tive Lane Keeping Assist .....................215
Ac tivating/deactivating ...................... .217
Fu nction ............................................... 215
Sensitivity (function/no tes) ................. 218
Setting the sensitivity .......................... 218
Sy stem limits ....................................... 215
Tr ailer operation .................................. .215
Ad aptive brake lights ..............................17 7Ad
aptive cruise control
see Dis tance Pilot DISTRONIC
Ad aptive functions, MULTIBEAM LED
see Intelligent Light Sy stem
Ad aptive Highbeam Assist Plus
Ac tivating/deactivating ...................... .120
Fu nction ............................................... 11 9
Ad Blue ®
..................................................... 411
Ad ditives .............................................. 411
Filling capacity ..................................... 412
No tes ................................................... 15 6
Purity ....................................................4 11
Ad ditional door lo ck.................................. 63
Ad diti ves................................................... 412
Ad Blue ®
............................................... 411
Engine oil ............................................. 412
Fu el ...................................................... 41 0
Ad diti ves (engine oil)
see Additives
Ad diti ves (fuel)
see Fuel
Ad dress book
see Contacts Index
47 9

Ad
justing the balance/ fader
Burmes ter®
sur round sound sy stem ... 343
Ad justing the sound focus
Burmes ter®
sur round sound sy stem ... 344
Ad versewe ather light ............................ .118
Af ter-sales service centre
see ASS YST PLUS
AIR BODY CONT ROL................................ .191
Setting ................................................. 19 3
Suspension .......................................... 191
Air conditioning sy stem
see Climate control
Air distribution ........................................ 12 9
Air freshener sy stem
see Frag rance sy stem
Air suspension see AIR BODY CONTROL
Air vents ................................................... 13 8
Ad justing (front) .................................. 13 8
Ad justing (rear) .................................... 13 9
Ad justing the AIRSCARF vents ............. 14 0
Glo vebox .............................................1 39Air
vents
see Air vents
Ai r-re circulation mode ............................ 13 2
Airbag ........................................................ .32
Ac tivation .............................................. 26
Fr ont airbag ...........................................32
Head airbag ........................................... 32
Ins tallation locations ............................ .32
Knee airbag ........................................... 32
Overview ............................................... 32
Pr otection ..............................................33
Re duced pr otection ...............................34
Side impact airbag ................................ 32
AI RC AP
Ac tivating .............................................. 80
Deactivating .......................................... 80
Ai rflow ...................................................... 12 9
AIRS CARF
Switching on/off ................................... 97
AIRS CARF vents
Ad justing ............................................. 14 0
Alarm see Panic alarm Alarm sy
stem
see ATA (anti-theft alarm sy stem)
Alternative route
see Route
Ambient lighting ...................................... 121
Android Auto ............................................ 304
Connecting a mobile phone ................. 304
Ending ................................................. 305
Overview ............................................. 304
To ne settings ....................................... 305
Tr ans ferred vehicle data ......................3 05
Animals Pets in theve hicle ................................. 58
Anti-lock braking sy stem
see ABS (Anti-lock Braking Sy stem)
Anti-theft alarm sy stem
see ATA (anti-theft alarm sy stem)
Anti-theft pr otection
Ad ditional door lock .............................. 63
Immobiliser ...........................................84
Anti-theft pr otection
see ATA (anti-theft alarm sy stem) 480
Index

Selecting pa
rkposition ........................ 151
Shifting toneutral ................................ 15 0
St eering wheel gearshift paddles ........ .151
Tr ansmission position display .............. 14 9
Tr ansmission positions ........................ 14 9
Axle load Perm issible .......................................... 406
Tr ailer operation .................................. .418 B
Bag hook .................................................. 106
Ball ne ck
Fo lding in/out ...................................... 219
BA S (Brake Assist Sy stem) .................... .168
Battery Key ........................................................ .61
Re mo tecontrol (s tationary heater) ...... 137
Battery (vehicle) Charging .............................................. 373
No tes ................................................... 371
St arting assis tance .............................. 373
Belt see Seat belt Bic
ycle rack
Tr ailer operation .................................. 222
Blind Spot Assist ...................................... 213
Ac tivating/deactivating ...................... .215
Fu nction/no tes .................................... 213
Sy stem limits ....................................... 213
Blind Spot Assi st
see Active Blind Spot Assi st
Blo wer
see Climate control
BlueTEC see AdBlue ®
Blue tooth ®
Ac tivating/deactivating ...................... .259
Setting up an Internet connection ....... .313
Settings ............................................... 259
Switching profile (DUN/PAN) .............. 314
Blue tooth ®
Au dio
Ac tivating ............................................ 331
De-authorising (de-regis tering) the
device .................................................. 331
Information .......................................... 328
Overview .............................................3 29Sear
ching for and auth orisingthe
device .................................................. 330
Switching device via NFC .................... 331
Boot lid .......................................................68
Ac tivating/deactivating the boot lid
opening limiter ...................................... 73
Closing .................................................. 69
HANDS-FREE ACCESS .......................... .71
Loc ked separately .................................73
Opening .................................................68
Opening dimensions ............................4 15
Boot lid see Boot lid
see Locking/unlocking
Boot separator Closing .................................................. 80
Opening ................................................. 80
Brake Assi stSystem
see BAS (Brake Assi stSystem)
Brake fluid Notes ................................................... 413
Brake forc e distribution
EBD (Elect ronic Brake forc e Distribu‐
tion) ..................................................... 171482
Index