Vehicles with halogen headlamps
:
Dipped-beam headlamp: H7 55 W
; Main-beam headlamp: H7 55 W
= Turn signal lamp: PY 21 W Tail lamps (vehicles with halogen headlamps)
: Rear foglamp: P 21 W
; Reversing lamp: W 16 W
= Turn signal lamp: PY 21 W Licence plate lamp (vehicles with halogen head-
lamps)
: Licence plate lamp: C 5 W Replacing the front bulbs
Fitting/removing the cover on the front wheel arch You must remove the cover of the front wheel
housing before you can change the front turn signal lamp.
X To remove: switch off the lights.
X Turn the front wheels inwards.
X Turn rotary knob :through 90°.
Cover ;is released.
X Push cover ;down.
X Turn rotary knob :through 90°.
Cover ;is locked.
Dipped-beam headlamps (halogen
lamps) X
Remove the cover in the front wheel arch
(Y page 129).
X Turn housing cover :anti-clockwise and
remove it.
X Turn bulb holder ;anticlockwise and pull
out. Replacing bulbs
129Lights and windscreen wipers Z
Replacing the rear bulbs
Opening and closing the side trim pan-
els View of left-hand side trim panel
You must open the side trim panel in the lug-
gage compartment before you can replace
the bulbs in the tail lamps.
X To open: turn release knob :anti-clock-
wise and remove side trim panel ;.
X To close: insert side trim panel ;and turn
release knob :clockwise.
Tail lamps Turn signals
X Switch off the lights.
X Open the luggage compartment.
X Open the side trim panel (Y page 131).X
Turn bulb holder :anti-clockwise and pull
out.
X Press the bulb lightly, turn it anti-clockwise
and pull it out. X
Insert the new bulb and turn it clockwise.
X Insert bulb holder :and turn it clockwise
until it engages.
X Close the side trim panel (Y page 131).
Reversing lamp and rear foglamp
Due to their location, have the bulbs in the
reversing lamp and the foglamp in the tailgate
replaced at a qualified specialist workshop. X
Switch off the lights.
X Open the tailgate.
X In recess ?on the inside of the closing
handle, prise out and remove the upper
section of handle =with a flat and smooth
object, e.g. a screwdriver.
X Pull the lower section of handle :using a
sharp, sudden movement to remove it from the trim and then place it to one side. Replacing bulbs
131Lights and windscreen wipers Z
X
Reach under the right-hand side of trim B
and apply a gentle jolting force along the
entire length of the trim in order to unclip it.
X Pull out connector Cof the surround light-
ing by releasing the latches.
X Place trim Bto one side. X
On the side where the bulb is to be
replaced, unclip the remaining part of trim
D from the assembly using a sudden,
sharp movement, until the bulb holder is
accessible. X
Remove bulb holder Eusing both sides of
lever F. Bulb holder
X Reversing lamp G: remove the bulb from
bulb holder E.
X Insert the new bulb into the bulb holder.
X Rear foglamp H: press the bulb gently
into bulb holder E, turn it anti-clockwise
and remove it from the bulb holder.
X Insert the new bulb into the bulb holder and
turn it clockwise.
X Reinsert the bulb holder until you hear it
engage audibly.
X Position trim Dand engage it in place by
tapping it with your hand.
X Before continuing with the installation,
check that all the metal clips are inserted in
the parts placed to one side: 2 clips ;in
the upper part of handle =and 5 clips A
in trim B.
X If not, remove the missing metal clips from
the metal openings in the tailgate and
insert them in the appropriate places.
X Take trim Band connect plug connector
C to the surround lighting.
i The surround lighting only illuminates
when the tailgate has been shut and reop-
ened.
X Position trim Band engage it in place by
tapping it with your hand, starting from the
outside.
X Clip in the lower section of handle :again.
X Insert and engage the upper section of han-
dle =into lower section :.132
Replacing bulbsLights and windscreen wipers
You should drive particularly carefully on slip-
pery road surfaces. Avoid sudden accelera-
tion, steering and braking manoeuvres. Do
not use cruise control or DISTRONIC PLUS.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
X Vehicles with manual transmission:
shift to neutral.
X Vehicles with automatic transmission:
shift the transmission to position N.
X Try to bring the vehicle under control by
using corrective steering.
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Changes in the outside temperature are dis-
played after a short delay.
Indicated temperatures just above the freez-
ing point do not guarantee that the road sur-
face is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Further information on driving with snow
chains (Y page 355).
Further information on driving with summer
tyres (Y page 354).
Observe the notes in the "Winter operation"
section (Y page 354). Driving systems
Cruise control
General notes Cruise control maintains a constant road
speed for you. It brakes automatically in order to avoid exceeding the set speed. You must
select a lower gear in good time on long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer. For vehi-
cles with automatic transmission, you need to have selected manual drive program M
(Y page 175). By doing so, you will make use of the braking effect of the engine. This
relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly.
Use cruise control only if road and traffic con-
ditions are appropriate for maintaining a
steady speed for a prolonged period. You canstore any road speed above 30 km/h.
The speed indicated in the speedometer maydiffer slightly from the speed stored.
Important safety notes If you fail to adapt your driving style, cruise
control can neither reduce the risk of an acci-
dent nor override the laws of physics. Cruise
control cannot take into account road,
weather or traffic conditions. Cruise control is
only an aid. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed, for braking in good time, and for staying in
lane.
Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed, e.g.
in heavy traffic or on winding roads
R on smooth or slippery roads. Braking or
accelerating can cause the drive wheels to
lose traction and the vehicle could then
skid
R when there is poor visibility, e.g. due to fog,
heavy rain or snow
If there is a change of drivers, advise the new driver of the speed stored. 188
Driving systemsDriving and parking
Under the following circumstances, the
reversing camera will not function, or will
function in a limited manner:
R if the boot lid is open
R in heavy rain, snow or fog
R at night or in very dark places
R if the camera is exposed to very bright light
R if the area is lit by fluorescent bulbs or LED
lighting (the display may flicker)
R if there is a sudden change in temperature,
e.g. when driving into a heated garage in
winter
R if the camera lens is dirty or obstructed.
Observe the notes on cleaning
(Y page 328)
R if the rear of your vehicle is damaged. In this
case, have the camera position and setting checked at a qualified specialist workshop
The field of vision and other functions of the
reversing camera may be restricted due to
additional accessories on the rear of the vehi-
cle (e.g. licence plate holder, bicycle rack).
Activating/deactivating the reversing
camera X
To activate: make sure that the key is in
position 2in the ignition lock.
X Make sure that the Activation by R
Activation by R
gear
gear function is selected in Audio 20/ COMAND Online; see the Digital Owner's
Manual.
X Engage reverse gear.
The area behind the vehicle is shown with
guide lines in the Audio 20/COMAND
Online display.
The image from the reversing camera is
available throughout the manoeuvring
process.
X To change the function mode for vehi-
cles with trailer tow hitch: using the
Audio 20/COMAND controller, select sym- bol :for the "Reverse parking" function or
symbol ;for "Coupling up a trailer".
The symbol of the selected function is high- lighted.
To deactivate: the reversing camera deacti-
vates if you shift the transmission to Por after
driving forwards a short distance.
Displays in the Audio 20/COMAND dis-
play The reversing camera may show a distorted
view of obstacles or show them incorrectly or
not at all. Obstacles are not shown by the
reversing camera in the following locations:
R very close to the rear bumper
R under the rear bumper
R in the area immediately above the tailgate
handle
! Objects not at ground level may appear to
be further away than they actually are, e.g.:
R the bumper of a parked vehicle
R the drawbar of a trailer
R the ball coupling of a trailer tow hitch
R the rear section of an HGV
R a slanted post
Use the guidelines only for orientation.
Approach objects no further than the bot-
tom-most guideline. 212
Driving systemsDriving and parking
Display messages
Possible causes/consequences and
M
MSolutions b
Rear fog lamp
Rear fog lamp The rear foglamp is faulty.
X Tail lamps (vehicles with halogen headlamps): replace the
bulb (Y page 128).
X Tail lamps (vehicles with LED headlamps): visit a qualified
specialist workshop. b
Front Front
left
leftparking
parking
lamp
lamp orFront
Front
right parking lamp
right parking lamp The front left or front right parking lamp is faulty.
X Visit a qualified specialist workshop. b
Reversing light Reversing light The reversing lamp is faulty.
X Tail lamps (vehicles with halogen headlamps): replace the
bulb (Y page 128).
X Tail lamps (vehicles with LED headlamps): visit a qualified
specialist workshop. b
Left tail lamp Left tail lamp
or
Right tail lamp
Right tail lamp The left or right-hand tail lamp is faulty.
X Visit a qualified specialist workshop. b
Left daytime driv‐ Left daytime driv‐
ing lamp ing lamp
orRight
Right
daytime driving
daytime driving
lamp lamp The left or right-hand daytime driving lamp is faulty.
X Visit a qualified specialist workshop. b
Malfunction See Malfunction See
Owner's Manual Owner's Manual The exterior lighting is faulty.
X Visit a qualified specialist workshop. Vehicles with trailer tow hitch: a fuse may have blown.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 181).
X Check the fuses (Y page 349).
X If necessary, replace the blown fuse. Observe the warning notes
as you do so.
If the display message continues to be displayed: X Visit a qualified specialist workshop. Display
messages
267On-board computer and displays Z
Display messages
Possible causes/consequences and
M
MSolutions b
AUTO AUTO
lights
lights inoper‐
inoper‐
ative
ative The light sensor is faulty.
X Visit a qualified specialist workshop. b
Switch off lights Switch off lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Turn the light switch to Ã.Adaptive Adaptive
Main-beam
Main-beam
Assist currently
Assist currently
unavailable See unavailable See
Owner's Manual Owner's Manual Adaptive Highbeam Assist is deactivated and temporarily inoper-
ative. Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
X Clean the windscreen.
If the system detects that the camera is fully operational again, the
Adaptive Main-beam Assist available again
Adaptive Main-beam Assist available again message is
displayed.
Adaptive Highbeam Assist is operational again. Adaptive Adaptive
Main-beam
Main-beam
Assist inoperative
Assist inoperative Adaptive Highbeam Assist is faulty.
X
Visit a qualified specialist workshop. Engine
Display messages
Possible causes/consequences and
M MSolutions +
Top Top
up
upcoolant
coolant See
See
Owner's Manual
Owner's Manual The coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, observing the warning notes before doing so
(Y page 322).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. ? The fan motor is faulty.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g.
driving in mountainous terrain and stop-start traffic. 268
Display
messagesOn-board computer and displays
Display messages
Possible causes/consequences and
M
MSolutions Lane Keeping
Lane Keeping
Assist currently Assist currently
unavailable See unavailable See
Owner's Manual Owner's Manual Lane Keeping Assist is deactivated and temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
R there have been no lane markings for an extended period
R the lane markings are worn, dark or covered, e.g. by dirt or snow
Once the causes listed above no longer apply, the display message
goes out.
Lane Keeping Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle to prevent it from rolling away (Y page 181).
X Clean the windscreen. Lane Keeping Lane Keeping
Assist inoperative Assist inoperative Lane Keeping Assist is faulty.
X Visit a qualified specialist workshop. Blind Spot Assist
Blind Spot Assist
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual Blind Spot Assist is temporarily inoperative. Possible causes:
R the function is impaired due to heavy rain or snow
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation
R the radar sensor system is outside the operating temperature
range
The yellow 9indicator lamps also light up in the exterior mir-
rors.
Once the causes listed above no longer apply, the display message goes out.
Blind Spot Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 181).
X Restart the engine. 272
Display
messagesOn-board computer and displays