warning light MERCEDES-BENZ C-CLASS SALOON 2014 Service Manual

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos- sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 27). Correct driver's seat position
G
WARNING
You could lose control of the vehicle while
driving if you:
R adjust the driver's seat, steering wheel or
mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirrors and fasten your seat
belt before starting the engine. X
Observe the safety guidelines on seat
adjustment (Y page 119).
X Make sure that seat =is correctly adjus-
ted.
Manual and electrical seat adjustment
(Y page 120)
Electrical seat adjustment (Y page 121)
When adjusting the seat, make sure that:
R you are as far away from the driver's airbag
as possible
R you are sitting in a normal upright position
R you can fasten the seat belt properly
R you have moved the backrest to an almost
vertical position
R you have set the seat angle so that your
thighs are gently supported
R you can depress the pedals properly
R your legs are not fully extended
X Check whether the head restraint is adjus-
ted correctly.
When doing so, make sure that you have
adjusted the head restraint so that the back of your head is supported at eye level by the centre of the head restraint.
X Observe the safety guidelines on steering
wheel adjustment (Y page 125).
X Make sure that steering wheel :is adjus-
ted correctly.
Adjusting the steering wheel manually
(Y page 125)
Adjusting the steering wheel electrically
(Y page 126)
When adjusting the steering wheel, make
sure that:
R you can hold the steering wheel with your
arms slightly bent
R you can move your legs freely
R you can see all the displays in the instru-
ment cluster clearly
X Observe the safety guidelines for seat belts
(Y page 47).
X Check whether you have fastened seat
belt ;properly (Y page 49).118
Correct driver's seat positionSeats, steering wheel and mirrors

X
Release the rear seat backrest and fold it
slightly forwards (Y page 372).
X To remove: pull the head restraint up to
the stop.
X Press release catch :and pull the head
restraint out of the guides.
X To refit: insert the head restraint so that
the notches on the bar are on the left when
viewed in the direction of travel.
X Push the head restraint down until you hear
it engage in position.
X Fold back the rear seat backrest until it
engages. Adjusting the 4-way lumbar support
:
To raise the backrest contour
; To soften the backrest contour
= To lower the backrest contour
? To harden the backrest contour
You can adjust the contour of the front seat
backrests individually to provide optimum
support for your back. Switching the seat heating on/off
Activating/deactivating G
WARNING
If you repeatedly switch on seat heating, the
seat cushion and backrest padding may
become very hot. The health of vehicle occu-
pants with limited temperature sensitivity or a limited ability to react to excessively high temperatures may be affected or they may
even suffer burn-like injuries. There is a risk of
injury.
Therefore, do not switch on the seat heating
repeatedly. The three red indicator lamps in the button
indicate the heating level you have selected.
The system automatically switches from level
3 to level 2after approximately eight
minutes.
The system automatically switches from level 2 to level 1after approximately ten minutes.
The system automatically switches off
approximately 20 minutes after it is set to
level 1.
X Turn the key to position 1or 2in the ignition
lock (Y page 181).
X To switch on: press button:repeatedly
until the desired heating level is set.
X To switch off: press button:repeatedly
until all the indicator lamps go out.
i If the battery voltage is too low, the seat
heating may switch off.
i If drive program Eis selected, the power
of the seat heating is reduced.
R Manual transmission (Y page 192)
R Automatic transmission (Y page 197) Seats
123Seats, ste ering wheel and mirrors Z

Problems with the seat ventilation
Problem
Possible causes/consequences and
M
MSolutions The seat ventilation has
switched off prema-
turely or cannot be
switched on. The on-board voltage is too low because too many electrical con-
sumers are switched on.
X Switch off electrical consumers that you do not need, such as
the rear window heating or interior lighting.
Once the battery is sufficiently charged, the seat ventilation can
be switched back on. Steering wheel
Important safety notes
G
WARNING
You could lose control of the vehicle while
driving if you:
R adjust the driver's seat, steering wheel or
mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirrors and fasten your seat
belt before starting the engine. G
WARNING
Children could become trapped by the steer-
ing wheel if they adjust it. There is a risk of
injury.
When leaving the vehicle, always take the key with you and lock the vehicle. Never leave
children unattended in the vehicle.
The electrically adjustable steering wheel can
still be adjusted when there is no key in the
ignition lock. Adjusting the steering wheel man-
ually
:
Release lever
; To adjust the steering wheel height
= To adjust the steering wheel position
(fore-and-aft adjustment)
X Push release lever :down completely.
The steering column is unlocked.
X Adjust the steering wheel to the desired
position.
X Push release lever :up completely.
The steering column is locked.
X Check if the steering column is locked.
When doing so, try to push the steering
wheel up or down or try to move it in the
fore-and-aft direction. Steering wheel
125Seats, steering wheel and mirrors Z

R
the exterior mirrors fold in automatically as
soon as you lock the vehicle from the out-
side
R the exterior mirrors fold out automatically
again as soon as you unlock the vehicle
i If the exterior mirrors have been folded in
manually, they do not fold out.
Exterior mirror pushed out of position If an exterior mirror has been pushed out of
position (forwards or backwards), proceed as
follows:
X Vehicles without electrically folding
exterior mirrors: move the exterior mirror
into the correct position manually.
X Vehicles with electrically folding exte-
rior mirrors: press and hold button :
until you hear a click and then the mirror
engaging in position (Y page 128).
The mirror housing is engaged again and
you can adjust the exterior mirrors as usual
(Y page 128). Automatic anti-dazzle mirrors
G
WARNING
Electrolyte may escape if the glass of an auto- matic anti-dazzle mirror breaks. Electrolyte is
harmful and causes irritation. It must not
come into contact with your skin, eyes, res-
piratory organs or clothing or be swallowed.
There is a risk of injury.
If you come into contact with electrolyte,
observe the following:
R immediately rinse off electrolyte from your
skin with water.
R immediately and thoroughly rinse electro-
lyte out of eyes using clean water.
R if electrolyte is swallowed, immediately
rinse out your mouth thoroughly. Do not
induce vomiting. R
if electrolyte comes into contact with skin
or eyes or is swallowed, seek medical atten-
tion immediately.
R immediately change out of clothing that has
been in contact with electrolyte.
R if an allergic reaction occurs, seek medical
attention immediately.
The rear-view mirror and the exterior mirror
on the driver's side automatically go into anti- dazzle mode if the following conditions are
met simultaneously:
R the ignition is switched on
R incident light from headlamps strikes the
sensor in the rear-view mirror
The mirrors do not dip if reverse gear is
engaged or if the interior lighting is switched
on. Parking position of the exterior mirror
on the front-passenger side
Using reverse gear :
Memory button M
; Adjustment button
= Button for the exterior mirror on the front-
passenger side
? Button for the exterior mirror on the driv-
er's side
You can set the front-passenger side exterior
mirror so that you can see the rear wheel on
that side as soon as you engage reverse gear.
You can store this position. Mirrors
129Seats, steering wheel and mirrors Z

3
T
Side lamps, licence plate and instru-
ment cluster lighting
4 Ã
Automatic headlamp mode, control-
led by the light sensor
5 L
Dipped-beam/main-beam head-
lamps
B R
Rear foglamp
If you hear a warning tone when you leave the
vehicle, the lights may still be switched on.
X Turn the light switch to Ã.
The exterior lighting (except the side lamps/
parking lamps) switches off automatically if
you:
R remove the key from the ignition lock
R open the driver's door with the key in posi-
tion 0
Automatic headlamp mode G
WARNING
When the light switch is set to Ã, the
dipped-beam headlamps may not be switched on automatically if there is fog, snow or othercauses of poor visibility due to the weather
conditions such as spray. There is a risk of an
accident.
In such situations, turn the light switch to
L.
The automatic headlamp feature is only an
aid. The driver is responsible for the vehicle
lighting at all times.
The daytime driving lights improve the detect- ability of your vehicle during the day.
When the side lamps and dipped-beam head-lamps are switched on, the green T(side
lamps) and L(dipped-beam headlamps)
indicator lamps in the instrument cluster light
up. Ã
is the preferred light switch setting. The
light setting is automatically selected accord- ing to the brightness of the ambient light
(exception: poor visibility due to weather con-
ditions such as fog, snow or spray):
R key in position 1in the ignition lock: the
side lamps are switched on or off automat- ically depending on the brightness of the
ambient light
R with the engine running: depending on the
ambient light conditions, the daytime driv-
ing lights or the parking and dipped-beam
headlamps are switched on or off automat-
ically
X To switch on automatic headlamp
mode: turn the light switch to Ã.
Dipped-beam headlamps
When the ignition is switched on and the light switch is in position L, the side lamps and
dipped-beam headlamps are switched on
even if the light sensor does not sense dark
ambient light conditions. This is advanta-
geous when there is fog or rain.
X To switch on the dipped-beam head-
lamps: turn the key in the ignition lock to
position 2or start the engine.
X Turn the light switch to L.
The green Lindicator lamp in the instru-
ment cluster lights up.
Rear foglamp
The rear foglamp improves the visibility of
your vehicle in heavy fog for the following
traffic. Please observe the country-specific
laws on the use of rear foglamps.
X To switch on the rear foglamp: turn the
key in the ignition lock to position 2or start
the engine.
X Turn the light switch to LorÃ. Exterior lighting
135Lights and windscreen wipers Z

Combination switch
Turn signals :
Main-beam headlamps
; Turn signal, right
= Headlamp flasher
? Turn signal, left
X To indicate briefly: press the combination
switch briefly to the pressure point in the
direction of arrow ;or?.
The corresponding turn signal flashes three
times.
X To indicate: press the combination switch
beyond the pressure point in the direction
of arrow ;or?.
Main-beam headlamps X
To switch on the main-beam head-
lamps: turn the key in the ignition lock to
position 2or start the engine.
X Turn the light switch to LorÃ.
X Press the combination switch beyond the
pressure point in the direction of arrow :.
In the Ãposition, the main-beam head-
lamps are only switched on when it is dark
and the engine is running.
The blue Kindicator lamp in the instru-
ment cluster lights up when the main-beam headlamps are switched on.
X To switch off the main-beam head-
lamps: move the combination switch back
to its normal position.
The blue Kindicator lamp in the instru-
ment cluster goes out. If Adaptive Highbeam Assist is active, it con-
trols activation and deactivation of the main-
beam headlamps (Y page 139).
Headlamp flasher X
To switch on: turn the key in the ignition
lock to position 1or 2, or start the engine.
X Pull the combination switch in the direction
of arrow =. Hazard warning lamps
X
To switch on the hazard warning lamps:
press button :.
All turn signals flash. If you now switch on a turn signal using the combination switch,
only the turn signal lamp on the corre-
sponding side of the vehicle will flash.
X To switch off the hazard warning lamps:
press button :.
The hazard warning lamps switch on auto-
matically if:
R an airbag is deployed or
R the vehicle decelerates rapidly from a
speed of above 70 km/h and comes to a
standstill
The hazard warning lamps switch off auto-
matically if the vehicle reaches a speed of
above 10 km/h again after a full brake appli- cation.
The hazard warning lamps continue to oper-
ate even if the ignition is switched off. Exterior lighting
137Lights and windscreen wipers Z

Not active:
if you are driving at speeds below
80 km/h following activation
Extended range foglamps The extended range foglamps reduce the
glare experienced by the driver and improve
the illumination of the edge of the carriage-
way.
Active: if you are driving at speeds below
70 km/h and you switch on the rear foglamp
Not active: if, following activation, you are
driving at speeds above 100 km/h or if you
switch off the rear foglamp Adaptive Highbeam Assist Plus
General notes With Adaptive Highbeam Assist Plus, you can
automatically switch between dipped-beam,
partial main-beam and main-beam head-
lamps.
Partial main-beam illumination is a form of
illumination whereby the main beam is direc-
ted past other road users. Other road users
are kept out of the main-beam. This prevents
glare. If there is a vehicle in front, for example, the main-beam headlamps illuminate the
areas to its right and left, and the vehicle in
front is illuminated by the dipped-beam head-
lamps.
The system automatically adapts the dipped-
beam headlamp range depending on the dis-
tance to the other vehicle. Once the system
no longer detects any other vehicles, it
switches on the main-beam headlamps again.
If the main-beam or partial main-beam head-
lamps are causing too much reflection from
traffic signs, the lights are automatically dim- med and glare for the driver caused by the
reflections is thus avoided.
The system's optical sensor is located behind
the windscreen near the overhead control
panel.
Important safety notes G
WARNING
Adaptive Highbeam Assist Plus does not rec-
ognise road users:
R who have no lights, e.g. pedestrians
R who have poor lighting, e.g. cyclists
R whose lighting is blocked, e.g. by a barrier
In very rare cases, Adaptive Highbeam Assist
Plus may not recognise road users who do
have lights, or may recognise them too late. In this, or in similar situations, the automatic
main-beam headlamps will not be deactivated
or will be activated despite the presence of
other road users. There is a risk of an acci-
dent.
Always carefully observe the traffic conditions and switch off the main-beam headlamps in
good time. Exterior lighting
139Lights andwindscreen wipers Z

?
u Switches the rear interior lighting
on/off
A p Switches the right-hand front read-
ing lamp on/off
Control panel in the grab handle (rear
compartment) :
Reading lamp
; p Switches the reading lamp on/off Interior lighting control
General notes In order to prevent the vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time,
unless the key is in position 2in the ignition
lock.
The colour, brightness and display lamp for
the ambient lighting may be set using
COMAND Online or Audio 20 (see the sepa-
rate operating instructions).
Automatic interior lighting control X
To switch on/off: press the|button.
When the automatic interior lighting con-
trol is activated, the button is flush with the overhead control panel.
The interior lighting automatically switches
on if you:
R unlock the vehicle
R open a door
R remove the key from the ignition lock The interior lighting is activated for a short
time when the key is removed from the igni-
tion lock. This delayed switch-off can be
adjusted using COMAND Online or Audio 20
(see the separate operating instructions).
Manual interior lighting control X
To switch the front interior lighting on/
off: press the cbutton.
X To switch the rear interior lighting on/
off: press the ubutton.
X To switch the reading lamps on/off:
press the pbutton. Crash-responsive emergency lighting
The interior lighting is activated automatically
if the vehicle is involved in an accident.
X To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or X Lock and then unlock the vehicle using the
key. Replacing bulbs (vehicles with LED
headlamps)
The front and rear light clusters of your vehi-
cle are equipped with LED light bulbs. Do not
replace the bulbs yourself. Contact a qualified specialist workshop which has the necessaryspecialist knowledge and tools to carry out
the work required.
Lamps are an important aspect of vehicle
safety. You must therefore make sure that
these function correctly at all times. Have the
headlamp setting checked regularly. Replacing bulbs (vehicles with LED headlamps)
141Lights and windscreen wipers Z

Replacing bulbs (vehicles with halo-
gen headlamps) Important safety notes
G
WARNING
Bulbs, lamps and plug connectors can
become very hot during use. When replacing a bulb, you could burn yourself on these com-
ponents. There is a risk of injury.
Allow these components to cool down before replacing the bulb.
Do not use a bulb that has been dropped or if
its glass tube has been scratched.
The bulb may explode if:
R you touch it
R it is hot
R you drop it
R you scratch it
Only operate bulbs in enclosed lamps
designed for that purpose. Only fit spare
bulbs of the same type and the specified volt- age.
Marks on the glass tube reduce the service
life of the bulbs. Do not touch the glass tube
with your bare hands. If necessary, clean the
glass tube when cold with alcohol or spirit and
rub it off with a lint-free cloth.
Protect bulbs from moisture during opera-
tion. Do not allow bulbs to come into contact
with liquids.
Replace only the bulbs listed (Y page 142).
Have the bulbs that you cannot replace your- self replaced at a qualified specialist work-
shop.
If you require assistance replacing bulbs, con-
sult a qualified specialist workshop.
If the new bulb still does not light up, consult
a qualified specialist workshop.
Bulbs and lamps are an important aspect of
vehicle safety. You must therefore make sure that these function correctly at all times.
Have the headlamp setting checked regularly. Overview of bulb replacement – bulbs
You can replace the following bulbs. The
details for the bulb type can be found in the
legend. Vehicles with halogen headlamps
:
Dipped-beam headlamp: H7 55 W
; Main-beam headlamp: H7 55 W
= Turn signal lamp: PWY 24 W Tail lamp (halogen headlamps)
:
Turn signal lamp: P 21 W
; Reversing lamp: W 16 W 142
Replacing bulbs (vehicles with halogen headlamps)Lights and windscreen wipers

X
Insert the new bulb into the bulb holder.
X Insert the bulb holder again.
X Turn wing nut :90° clockwise.
X Insert the connector.
X Close the side trim panel (Y page 144).Windscreen wipers
Switching the windscreen wipers on/
off
! Do not operate the windscreen wipers
when the windscreen is dry, as this could
damage the wiper blades. Moreover, dust
that has collected on the windscreen can
scratch the glass if wiping takes place when the windscreen is dry.
If it is necessary to switch on the wind-
screen wipers in dry weather conditions,
always operate them using washer fluid.
! If the windscreen wipers leave smears on
the windscreen after the vehicle has been
washed in an automatic car wash, this may
be due to wax or other residue. Clean the
windscreen with washer fluid after an auto- matic car wash.
! Intermittent wiping with rain sensor: due
to optical influences and the windscreen
becoming dirty in dry weather conditions,
the windscreen wipers may be activated
inadvertently. This could damage the wind- screen wiper blades or scratch the wind-
screen.
For this reason, you should always switch
off the windscreen wipers in dry weather. 1
$ Windscreen wipers off
2 Ä Intermittent wipe, low (rain sensor
set to low sensitivity)
3 Å Intermittent wipe, high (rain sensor
set to high sensitivity)
4 ° Continuous wipe, slow
5 ¯ Continuous wipe, fast
B í Single wipe/ îto wipe the wind-
screen using washer fluid
X Turn the key to position 1or 2in the ignition
lock (Y page 181).
X Turn the combination switch to the corre-
sponding position.
Vehicles with a rain sensor: in theÄor
Å position, the appropriate wiping fre-
quency is automatically set according to the
intensity of the rain. In the Åposition, the
rain sensor is more sensitive than in the Ä
position, causing the windscreen wipers to
wipe more frequently.
If the wiper blades are worn, the windscreen
will no longer be wiped properly. This could
prevent you from observing the traffic condi-
tions. Replacing the wiper blades
Important safety notes G
WARNING
If the windscreen wipers begin to move while
you are changing the wiper blades, you can be trapped by the wiper arm. There is a risk of
injury. Windscreen wipers
145Lights and windscreen wipers
Z