trailer MERCEDES-BENZ E-CLASS ESTATE 2012 Service Manual

Display messages Possible causes/consequences and
M Solutions
b
Trailer left indi‐
cator or
Trailer right indicator The lef
torright-hand trailer tur nsignal lamp is faulty.
X Check whether you are permitted to replace the bulb yourself.
or
X Visit a qualified specialist workshop. b
Trailer brake lamp The trailer brake lamp is faulty.
X
Check whether you are permitted to replace the bulb yourself.
or
X Visit a qualified specialist workshop. b
Rear left indica‐
tor or
Rear right indicator The rear left-hand or rear right-hand tur
nsignal is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 135).
or
X Visit a qualified specialist workshop. b
Front left indica‐
tor or
Front right indicator The front left-hand or front right-hand turn signal is faulty.
X
Check whether you are permitted to replace the bulb yourself
(Y page 135).
or
X Visit a qualified specialist workshop. b
Left
mirror indica‐
tor or
Right mir‐ ror indicator The turn signal in the left-hand or right-hand exterior mirror is
faulty.
X
Check whether you are permitted to replace the bulb yourself
(Y page 135).
or
X Visit a qualified specialist workshop. b
Third brake lamp The third brake lamp is faulty.
X
Check whether you are permitted to replace the bulb yourself
(Y page 135).
or
X Visit a qualified specialist workshop. b
Left-hand tail
lamp/brake
lamp orRight-hand
tail lamp/brake
lamp The left or right-hand tail lamp/brake lamp is faulty.
X
Check whether you are permitted to replace the bulb yourself
(Y page 135).
or
X Visit a qualified specialist workshop. 276
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
b
Left daytime driv‐
ing lamp or
Right daytime driving
lamp The left-hand or right-hand daytime driving lamp is faulty.
X
Chec kwhether you are permitted to replace the bulb yourself
(Y page 135).
or
X Visit a qualified specialist workshop. b
Intell. Light Sys‐
tem inoperative The Intelligent Light System is faulty. The lights remain available
without the Intelligent Light System.
X
Visit a qualified specialist workshop. b
Malfunction See
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
Check the fuses (Y page 375).
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. b
AUTO
lights inoper‐
ative The light sensor is faulty.
X
Visit a qualified specialist workshop. b
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 Main-beam
Assist inoperative Adaptive Highbeam Assist is faulty.
X
Visit a qualified specialist workshop. Adaptive Main-beam
Assist currently
unavailable See
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 Cleant he windscreen.
If the system detects that the camera is fully operational again,
the Adaptive Main-beam Assist available again message
is displayed.
Adaptive Highbeam Assist is operational again. 278
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
Lane Keeping
Assist inopera‐
tive or
Active Lane Keeping
Assist inoperative Lane Keeping Assis
torActive Lane Keeping Assist is faulty.
X Visit a qualified specialist workshop. Lane Keeping
Assist currently
unavailable See
Owner's Manual or
Active Lane Keep‐ ing Assist cur‐
rently unavailable
See Owner's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily inop-
erative.
You have established the electrical connection between the trailer
and your vehicle.
X Press aon the steering wheel to confirm the display mes-
sage.
Blind Spot Assist or Active Blind Spot Assist is deactivated while
towing a trailer. Blind Spot Assist or Active Blind Spot Assist is temporarily inop-
erative .Possible causes:
R the sensors are dirty.
R the function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
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.
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 or Active 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 183).
X Clean the sensors (Y page 354).
X Restart the engine. Blind Spot Assist
inoperative or
Active Blind Spot Assist inoperative Blind Spot Assist or Active Blind Spot Assist is faulty.
The yellow 9indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Display messages
285On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
M
or? The bonne
tis open. Awarning tone also sounds.
G WARNING
The open bonne tmay then bloc kyour view when the vehicle is in
motion.
There is a risk of an accident.
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 183).
X Close the bonnet.
If the active bonnet (pedestrian protection) has been triggered:
X Reset the bonnet (Y page 344).
X Close the bonnet. Active bonnet mal‐
function See Own‐
er's Manual The active bonnet (pedestrian protection) is not active due to a
malfunction.
X
Visit a qualified specialist workshop. C At least one door is open.
Awarning tone also sounds.
X Close all doors. _
Rear left seat
backrest not
locked or
Rear right seat back‐
rest not locked Saloon with through-loading feature in the rear bench seat:
The backres
tinthe rear is not engaged on the left-hand and/or
right-hand side. Awarning tone also sounds.
X Push the backres tback until it engages. j
Check trailer
hitch lock The trailer tow hitch is no
tcorrectly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Apply the parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 237). &
inoperative Bat‐
tery low The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on (Y page 151).
X Drive for a longer distance.
The battery is being charged. The auxiliary heating is operational
again as soon as the on-board electrical system voltage is suf-
ficient. Display messages
295On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
!
The yellow ABS warning
lamp is lit while the
engine is running. ABS (Anti-lock Brake System) has been deactivated due to a fault.
For this reason, BAS (Brake Assist), BAS PLUS, ESP ®
(Electronic
Stability Program), PRE-SAFE ®
,P RE-SAFE ®
Brake ,the HOLD func-
tion, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation are also deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic trans-
mission, will not be available. Indicator and warning lamps in the instrument cluster
301On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
!
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds. EBD is not available due to a malfunction. Therefore, ABS, BAS,
BAS PLUS, ESP
®
, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD func-
tion, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation, for example, are not available either.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Jäå!
The red brake warning
lamp, the yellow ESP
®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running. ABS and ESP
®
are not available due to a fault. Therefore, BAS, BAS
PLUS, EBD,P RE-SAFE®
,P RE-SAFE ®
Brake, the HOLD function, hill
start assist, the adaptive brake lights and ESP ®
trailer stabilisa-
tion, for example, are no tavailable either.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The dange rofskidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visi taqualified specialist workshop. 302
Indicator and warning lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
äå
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, BAS PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD
function, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation are not available due to a malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. J
The red brake system
warning lamp comes on
while the vehicle is
moving. A warning tone
also sounds.
You are driving with the parking brake applied.
X
Release the parking brake.
The warning lamp goes out and the warning tone ceases. 6
The red SRS warning
lamp is lit while the
engine is running.
There is a malfunction in the SRS (Supplemental Restraint Sys-
tem).
G WARNING
The airbags or belt tensioners may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury.
X Drive on carefully.
X Have SRS checked at a qualified specialist workshop immedi-
ately.
For further information about the Supplemental Restraint System,
see (Y page 43). 304
Indicator and warning lamps in the instrument clusterOn-board computer and displays

X
Use clear water and a soft cloth to clean
camera lens :.
Cleaning the exhaust tail pipes !
Do not clean the exhaust pipe with alka-
line-based cleaning agents, such as wheel
cleaner.
Impurities combined with the effects of road
grit and corrosive environmental factors may
cause flash rust to form on the surface. You
can restore the original shine of the exhaust
pipe by cleaning it regularly, especially in win-
ter and after washing.
X Cleant he exhaust pipe with a chrome care
product tested and approved by Mercedes-
Benz.
Cleaning the trailer tow hitch H
Environmental note
Dispose of oily and greasy cloths in an envi-
ronmentally-responsible manner.
! Do not clean the ball coupling with a high-
pressure cleaner. Do not use solvents.
! Observe the note on care provided by the
trailer manufacturer. The ball coupling must be cleaned if it
becomes dirty or corroded.
X Remove rust, e.g. with a wire brush.
X Remove dirt with a clean, lint-free cloth or
a brush. X
After cleaning, lightly oil or grease ball cou-
pling :.
X Check that the vehicle's trailer tow hitch is
working properly.
i You can also have the maintenance work
on the ball coupling and the trailer tow hitch
carried out by a qualified specialist work-
shop. Interior care
Cleaning the display !
For cleaning, do not use any of the fol-
lowing:
R alcohol-based thinner or petrol
R abrasive cleaning agents
R commercially-available household clean-
ing agents
These may damage the display surface. Do
not put pressure on the display surface
when cleaning. This could lead to irrepara-
ble damage to the display.
X Before cleaning the display, make sure that
it is switched off and has cooled down.
X Cleant he display surface using a commer-
cially available microfibre cloth and TFT/
LCD display cleaner.
X Dry the display surface using a dry micro-
fibre cloth.
Cleaning Night View Assist Plus !
Never clean the camera lens. When clean-
ing the field of vision of the driving systems,
make sure that you do not spray glass
cleaner on the camera lens. If the camera
lens is dirty, visit a qualified specialist work-
shop. Care
355Maintenance and care Z

Towing and tow-starting
Important safety notes
G
WARNING
Hybrid vehicles: it is imperative tha tyou read
the "HYBRID" supplement. Otherwise, you
may not recognise dangers. G
WARNING
If you tow the vehicle, you must use a rigid
towing bar if:
R the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the power supply
or the vehicle's electrical system.
The power assistance for the steering and the
brake force booster do not work when the
engine is not running. You will need more
force to steer and brake, you may have to
depress the brake pedal with maximum force.
Before towing away, make sure that the steer-
ing can be moved and is not locked.
If you tow or tow-start another vehicle, its
weight must not exceed the maximum per-
missible gross vehicle weight of your vehicle. G
WARNING
The vehicle is braked when the HOLD function
or DISTRONIC PLUS is activated. Therefore,
deactivate HOLD and DISTRONIC PLUS if the
vehicle is to be towed.
! Only secure the tow rope or towing bar to
the towing eyes. The vehicle may otherwise
be damaged.
! Observe the following points when towing
with a tow rope:
R secure the tow rope on the same side on
both vehicles.
R the tow rope must not be longer than is
legally permitted. It should be marked in
the middle, e.g. with a white cloth
(30 x30c m) so thatothe rroad users are
aware that a vehicle is being towed. R
the tow rope may only be attached to the
towing eyes.
R observe the brake lamps of the towing
vehicle while driving. Always maintain a
distance so that the tow rope does not
sag.
R do not use steel cables or chains to tow
your vehicle. The vehicle could be dam-
aged.
! Do not use the towing eye for recovery,
this could damage the vehicle. If in doubt,
recover the vehicle with acrane.
! Pull away smoothly when towing away or
tow-starting a vehicle. If the tractive power
is too high, the vehicles could be damaged.
! To tow vehicles with KEYLESS-GO, use
the key instead of the Start/Stop button.
The automatic transmission may otherwise
switch to position Pwhen you open the
driver's or front-passenge rdoor which
could damage the transmission.
! You may tow the vehicle for a maximum
of 50km. A towing speed of 50 km/h must
not be exceeded.
For towing distances over 50 km, the entire
vehicle must be lifted up and transported.
! If you tow or tow-start another vehicle, its
weight must not exceed the maximu mper-
missible gross vehicle weight of your vehi-
cle.
Information on your vehicle's gross vehicle
weight rating can be found on the vehicle
identification plate (Y page 435).
Observe the legal requirement sfor the rele-
vant countries when towing and tow-starting.
It is better to have the vehicle transported
than to have it towed.
If the vehicle has suffered transmission dam-
age, have it transported on a transporter or
trailer.
When towing a vehicle with an automatic
transmission, the transmission must be in
position N. 372
Towing and tow-startingBreakdown assistance

The battery must be connected and charged.
Otherwise, you:
R
cannot turn the key in the ignition lock to
position 2
R cannot shift the transmission to position
N on vehicles with automatic transmission
Vehicles with automatic transmission:
release the selector lever lock manually to
move it out of position P(Y page 179).
i Deactivate the automatic locking feature
(Y page 90). You could otherwise be locked
out when pushing or towing the vehicle.
Deactivate tow-away protection
(Y page 79) before the vehicle is towed. Fitting/removing the towing eye
Fitting the towing eye G
WARNING
The exhaust tail pipe may be hot. You could
burn yourself if you touch the tail pipe. Be
particularly careful when removing the rear
cover. Example: Saloon, towing eye covers Vehicles with a trailer tow hitch: if you intend
to use the vehicle for towing, fold out the ball
coupling and connect the towbar to it
(Y
page 237).
The mountings for the removable towing eyes
are located in the bumpers. They are at the
front and at the rear, under the covers.
X Remove the towing eye from the vehicle
tool kit (Y page 361).
X Press the mark on cover :inwards in the
direction of the arrow.
X Take cover :off the opening.
X Screw the towing eye in clockwise to the
stop and tighten it.
Removing the towing eye X
Loosen the towing eye and unscrew it.
X Position cover :on the bumper and press
it until it engages.
X Place the towing eye in the vehicle tool kit. Towing the vehicle with the rear axle
raised
! The ignition must be switched off if you
are towing the vehicle with the rear axle
raised. Intervention by ESP ®
could other-
wise damage the brake system.
Only possible on vehicles without
4MATIC.
X Switch on the hazard warning lamps
(Y page 129).
X Turn the key in the ignition lock to position
0and remove the key from the ignition
lock.
X When leaving the vehicle, take the key or
the KEYLESS-GO key with you.
When towing your vehicle with the rear axle
raised, it is importan tthat you observe the
safety instructions (Y page 372). Towing and tow-starting
373Breakdown assistance Z