service MERCEDES-BENZ C-CLASS SALOON 2012 Repair Manual

#
Todeactivate full-sc reen mode: select
%. Ac
tivating or deactivating the frequency fix
function Multimedia sy
stem:
4 Radio 5
Z Options 5
Frequency fix #
Activate Oor deacti vate ª the function.
If th e function is activated, the set frequency
is ke pt eve n ifthere ception is poo r. Ta
gging music trac ks Multimedia sy
stem:
4 Radio
If ra dio stations pr ovide there leva nt information,
th is function allo wsyouto trans fer information
on the music track cur rently pl aying toan
Apple ®
device. You can then pur chase the audio
fi le from iTunes ®
. #
Select ♫→ Tag this song.
The track information is sa ved. Switching traf
fic announcements on/off Multimedia sy
stem:
4 System 5
õ Audio
5 Navigation and traffic announcements #
Activate Oor deacti vate ª the function.
or #
Press and hold the8 button on the multi‐
function steering wheel. Setting
the traf fic information service vol‐
ume increase Multimedia sy
stem:
4 System 5
õ Audio
5 Navigation and traffic announcements #
Select Traffic announcements volume
increase. #
Select No increase or avalue. Ac
tivating/deactivating radio text Multimedia sy
stem:
4 Radio 5
Z Options
5 Display radio text information #
Activate Oor deacti vate ª the function. TV
Information on
TVmode In
fo rm ation on copy right pr otection and
trademarks
Ubiquitous DTCP-MOST
Copyright ®
20 15 Ubiquitous Corp.
DV B and DVB logos are trademark s oftheDVB
Project.
The TVtuner enables reception of digital chan‐
nels according tothefo llowing standards:
R DVB-T
R DVB-T2
In some countries, thest andards may not be
av ailable, or may not be available in all areas. Multimedia sy
stem 361
Internal use only

ASS
YST PLUS se rvice inter val display Fu
nction of the ASS YST PLUS se rvice inter val
displ ay The ASS
YST PLUS service inter val display on the
instrument display pr ovides information on the
re maining time or dis tance be fore the next
service due date.
Yo u can hide this service display using the back
button on the left-hand side of thesteering
wheel.
Depending on how theve hicle is used, the
ASS YST PLUS service inter val display may
shor tenth e service inter val, e.g. in thefo llowing
cases:
R mainly short-dis tance driving
R when the engine is of ten le ftidling for long
periods
R intheeve nt of frequent cold start phases
R vehicles with a diesel particulate filter: in
th eev ent of frequently inter rupted rege nera‐
tion of the diesel particulate filter Mercedes-Benz
recommends avoiding such
operating conditions.
Yo u can obtain information concerning the serv‐
icing of your vehicle from a qualified specialist
wo rkshop, e.g. a Mercedes-Benz Service Centre. Displaying
the service due da te On-board computer:
4 Service 5
ASSYST PLUS
The next service due date is displa yed. #
Toexitth e displa y:press the back button
on the left-hand side of thesteering wheel.
Bear in mind thefo llowing related topic:
R Operating the on-board computer
(/ page 246). Infor
mation on regular maintenance work *
NO
TEPremature wearthro ugh failure to
obser veservice due dates Maintenance
workwhich is not car ried out at
th eright time or incomple tely can le adto
inc reased wear and damage totheve hicle. #
Adhere tothe prescribed service inter‐
va ls. #
Alw ays ha vethe prescribed mainte‐
nance workcar ried out at a qualified
specialist workshop. Special service
requ irements The prescribed service inter
val is based on nor‐
mal operation of theve hicle. Maintenance work
will need tobe per form ed more of ten if theve hi‐
cle is operated under arduous conditions or
increased loads.
The ASS YST PLUS service inter val display is only
an aid. The driver of theve hicle bears responsi‐
bility as rega rdsto whe ther maintenance work
needs tobe per form ed more of tenth an speci‐ 372
Maintenance and care
Internal use only

fi
ed based on the actual operating conditions
and/or loads.
Examples of arduous operating conditions:
R regular city driving with frequent intermedi‐
ate stops
R mainly short-dis tance driving
R frequent operation in mountainous terrain or
on poor road sur faces
R when the engine is of ten le ftidling for long
periods
R operation in particula rly dusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air filter, engine air cleaner, engine oil
and oil filter etc. changed more frequent ly. The
ty re s must be checked more frequently if the
ve hicle is operated under increased loads. Fur‐
th er information can be obtained at a qualified
specialist workshop. Battery disconnection periods
The ASS
YST PLUS service inter val display can
calculate the service due date only when the
battery is connec ted. #
Notedown the service due date displa yed on
th e instrument display before disconnecting
th e battery (/ page372). Engine com
partment Ac
tive bonn et(pedestrian pr otection) Operation of
the active bonnet (pedestrian
pr otection)
In cer tain accident situations, the actuation of
th e active bonn etreduces therisk of injury to
pedestrians. The rear area of the bonn etis
ra ised byappr oximately 85 mm.
Fo rth e drive tothewo rkshop, reset the actuated
active bonn etyourself (/ page373).
Af terth e active bonn ethas been actuated,
pedestrian pr otection may be limited.
Ha ve the full functionality of the active bonn et
re stored in a qualified specialist workshop. Re
setting the active bonnet &
WARNING Risk of burn s from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. Maintenance and care
373
Internal use only

#
With your hand flat, push down active bonnet
1 inthe area around the hinges on bo th
sides (ar rows).
In doing so, the actuator is depressurised
and you may hear a hissing sound.
The engine bonnet must en gage in position. #
Ifth e active bonn etcan be raised slight lyat
th ere ar in the area of the hinges, repeat the
st ep until it engages cor rectl y. Opening and closing
the bonnet &
WARNING Risk of accident due todriv‐
ing with the bonn etunlo cked
The bonn etmay open and block your vie w. #
Neverre lease the bonn etwhen driving. #
Before every trip, ensure that the
engine bonn etis loc ked. &
WARNING Risk of accident and inju ry
when opening and closing the bonn et
The bonnet may suddenly drop into the end
position.
There is a risk of injury for an yone in the
engine bonn et's range of mo vement. #
Do not open or close the bonn etifth ere
is a person in the bonn et's range of
mo vement. &
WARNING Risk of burn s when opening
th e bonn et
If yo u open the bonn etwhen the engine has
ove rheated or when there is a fire inthe
engine compartment, thefo llowing situations
may occur:
R You could come into contact with hot
ga ses.
R You could come into contact with other
hot, escaping operating fluids. #
Before opening the bonn et, allow the
engine tocool down. #
Intheeve nt of a fire inthe engine com‐
partment, keep the bonn etclosed and
call thefire service. &
WARNING Risk of injury duetomoving
parts
Components in the engine compartment may
continue running or start up sudden ly,even if
th e ignition is switched off.
Make sure of thefo llowing before per form ing
ta sks in the engine compartmen t: #
Switch the ignition off. #
Neverre ach into the danger zone sur‐
ro unding moving co mponents, e.g. the
ro tation area of thefa n. #
Remo vejewe llery and watches. #
Keep items of clo thing and hair away
from moving parts. 374
Maintenance and care
Internal use only

#
Park theve hicle on a le vel sur face. #
Pull oil dipstick 1out and wipe off. #
Slowly slide oil dipstick 1into the guide
tube tothestop, and pull it out again af ter
about thre e seconds.
R Oil le vel is cor rect: oil le vel is between 2
and 3.
R Oil le velto o low: oil le vel is at 3or
belo w. R
Oil le velto o high: oil le vel is abo ve2 . #
Ifth e oil le vel is too lo w,top up with 1 litre of
engine oil. #
Ifth e oil le vel is too high, drain off excess
engine oil. Consult a qualified specialist
wo rkshop.
Checking the engine oil le vel using the on-
board compu ter
Re quirements:
R The engine has an oil le vel sensor. If not, the
engine oil le vel can be checked only with the
oil dipstick (/ page376).
R The engine has been warmed up.
R The vehicle is par ked on a le vel sur face.
R The engine is running at idle speed.
R The bonnet is closed.
The engine oil le vel is de term ined during driving.
De term ining the engine oil le vel can take up to
30 minutes with a normal driving style and even
longer with an active driving style. On-board computer:
4 Service 5
Engine oil level
One of thefo llowing messages will appear on
th e multifunction display:
R Engine oil level Measuring now : measure‐
ment of the oil le vel is not yet possible. #
Repeat there qu est af ter a maximum of
30 minutes' driving.
R Engine oil level OK andthe bar display for
indicating the oil le vel on the multifunction
display is green and is between "min" and
"max": the oil le vel is cor rect.
R Engine oil level Add 1.0 l andthe bar display
fo r indicating the oil le vel on the multifunc‐
tion display is orange and is below "min": #
Add 1 l of engine oil.
R Reduce engine oil level andthe bar display
fo r indicating the oil le vel on the multifunc‐
tion display is orange and is abo ve"max": Main
tenance and care 377
Internal use only

#
Drain off any excess engine oil that has been
added. Todo so, consult a qualified specialist
wo rkshop.
R For engine oil level turn on ignition #
Switch on the ignition tocheck the engine oil
le ve l.
R Engine oil level System inoperative : The oil
le ve l sensor is defective or not connecte d.#
Consult a qualified specialist workshop.
R Engine oil level System currently unavail. #
Close the bonn et.
To pping up engine oil &
WARNING Risk of burn s from hot com‐
ponent parts in the engine compartment
Cer tain component parts in the engine com‐
partment can be very hot, e.g. the engine,
th e cooler and parts of theex haust sy stem. #
Allow the engine tocool down and only
to uch co mponent parts described in
th efo llowing. &
WARNING Risk offire and injury from
engine oil
If engine oil comes into con tact with hot
component parts in the engine compart‐
ment, it may ignite. #
Make sure that no engine oil is spilled
next tothefiller opening. #
Allow the engine tocool off and thor‐
oughly clean the engine oil from compo‐
nent parts before starting theve hicle. *
NO
TEEngine damage causedbyan
incor rect oil filter, incor rect oil or addi‐
tives #
Do not use engine oils or oil filters
which do not cor respond tothe specifi‐
cations explicitly prescribed forthe
service inter vals. #
Follow the instructions on the service
inter val display forch anging the engine
oil and obser vethe prescribed change
inter vals. #
Do not use additives. *
NO
TEDama gecaused bytopping up too
much engine oil To
o much engine oil can damage the engine
or the catalytic con verter. #
Have excess engine oil remo ved at a
qu alified specialist workshop. %
Depending on driving style, theve hicle con‐
sumes up to0.8 litr e of oil pe r10 00 km. The
oil consum ption may be higher than this
when theve hicle is new or if you frequently
drive at high engine speeds. 378
Maintenance and care
Internal use only

Note
s on paint work/matt finish paintwork
care Obse
rveth e no tes on cleaning and care toavo id
damaging the paintwor k.
Pa int
R Insect remains: soak with insect remo ver and
ri nse off the treated areas af terw ards.
R Bird droppings: soak with water and rinse off
af te rw ards.
R Tree resin, oils, fuels and greases: remo veby
ru bbing gently wi tha clo thsoaked in petro‐
leum ether or lighter fluid.
R Coolant and brake fluid: remo vewith a damp
clo thand clean water.
R Tarst ains: use tar remo ver.
R Wax: use silicone remo ver.
R Do not attach sticke rs,fi lms or similar mate‐
ri als.
R Remo vedirt immediately, where possible.
Matt finish
R Only use care products appr ovedfor
Mercedes-Benz. R
Do not polish theve hicle and light-alloy
wheels.
R Only use car washes that cor respond tothe
latest engineering standards.
R Do not use car wash programmes with a final
hot wax treatment.
R Do not use paint cleane rs, buf fing or polish‐
ing products, gloss preser vers, e.g. wax.
R Alw ays ha vepaintwork repairs car ried out at
a qu alified specialist workshop. Note
s on cleaning decorative foils Obser
vethe no tes on matt finish care in the
ch ap ter "No tes on paintwork/matt finish paint‐
wo rkcare" (/ page 383). They also apply to
matt decorative foils.
Obser vethe no tes on cleaning decorative foils to
av oid vehicle damage.
Cleaning
R For cleaning, use plenty of water and a mild
cleaning agent without additives or abrasive
subs tances, e.g. a car sha mpoo appr ovedfor
Mercedes-Benz. R
Remo vedirt immediatel y,where possible,
whilst avoiding rubbing too hard. There is
ot herwise a risk of damaging the decorative
fo il ir reparabl y.
R Ifth ere is dirt on thefinish or if the decora‐
tive foil is dull: use thePa int Cleaner recom‐
mended and appr oved for Mercedes-Benz.
R Insect remains: soak with insect remo ver and
ri nse off the treated areas af terw ards.
R Bird droppings: soak with water and rinse off
af te rw ards.
R Topreve ntwate rst ains, dry a foil-wrapped
ve hicle with a soft, absorbent clo thafter
eve rycar wash.
Av oiding dama getothe decorative foil
R The service life and colouring of decorative
foils are impaired by:
- sunlight
- temp erature, e.g. hot air blo wer
- weather conditions
- stone chippings and dirt
- chemical cleaning agents Maintenance and care
383
Internal use only

-
oily products
R Do not use polish on matt decorative foil.
Po lishing will ha vethe ef fect of shining the
fo il-wrapped sur face.
R Do not treat matt or stru ctured deco rative
fo ils with wax.Pe rm anent stains may occur.
Sc ratches, cor rosive deposits, areas af fected by
cor rosion and damage caused byincor rect care
cannot al ways be comple tely re paired. In such
cases, visit a qualified specialist workshop.
Yo u can obtain more information on care and
cleaning products from the manufacturer.
In the case of foil-wrapped sur faces, optical dif‐
fe re nces may occur between the sur faces that
we renot pr otected bya decorative foil af ter
re moving a decorative foil.
% Have wo rkor repairs todecorative foils car‐
ri ed out at a qualified specialist workshop,
e.g. in a Mercedes-Benz Service Centre. Note
s on care of car parts &
WARNING Risk of entrapment if the
windscreen wipers are swit ched on while
th e windscreen is being cleaned
If th e windscreen wipers are set in motion
while you are cleaning the windscreen or
wiper blades, you can be trapped bythe
wiper arm. #
Alw ays switch off the windscreen wip‐
ers and the ignition before cleaning the
windscreen or wiper blades. &
WARNING Risk of burn s fromtheta il‐
pipe and tailpipe trims
The exhaust tailpipe and tailpipe trims can
become very hot. If you come into contact
with these parts of theve hicle, you could
burn yourself. #
Alw ays be particular lycareful around
th eta ilpipe and theta ilpipe trims and
supervise children especially closely in
th is area. #
Allow vehicle parts tocool down before
to uching them. To
avo id damage totheve hicle, obser vethe
no tes on cleaning and care of thefo llowing vehi‐
cle parts:
Wheels and rims
R Use wate r and acid-free alloy wheel cleaners.
R Do not use acidic alloy wheel cleaners to
re mo vebrake dust. This could damage wheel
bolts and brake components.
R Toavo id cor rosion of the brake disks and
brakepads, drive theve hicle for a few
minutes af ter cleaning before parking it. The
brake disks and brakepads warm up and dry
out.
Wi ndo ws
R Clean the windo wsinside and outside with a
damp clo thand with a cleaning agent recom‐
mended for Mercedes-Benz.
R Do not use dry clo ths or abrasive or sol vent-
based cleaning agents toclean the inside of
windo ws. 384
Maintenance and care
Internal use only

If, af
terte n minutes, a tyre pressure of
200 kPa (2.0 bar/29 psi) has been attained: &
WARNING Risk of accident from driving
wi th sealed tyres
A tyre temp orarily sealed with tyre sealant
impairs the handling characteristics and is
not suitable for higher speeds. #
Adapt your driving style according lyand
drive carefull y. #
Do not exceed the maximum speed
limit with a tyre that has been repaired
using tyre sealant. #
Obser vethe maximum permissible speed for
a tyre sealed with tyre sealant 80 km/h. #
Affix th e upper section of the TIREFIT sticker
to the instrument clus ter in a location where
it will be easi lyseen bythe driver.
* NO
TEStaining from leaking tyre sealant Af
ter use, excess tyre sealant may leak out
from thefilling hose. #
Therefore, place thefilling hose in the
plastic bag that con tained the TIREFIT
kit. +
ENVIRONMEN
TALNO TEEnvironmental
pollution caused byenvironmen tally ir re‐
sponsible disposal Ty
re sealant contains polluta nts. #
Have the tyre sealant bottle disposed of
professionall y,e.g. at a Mercedes-Benz
Service Centre. #
Switch off the tyre inflation compressor. #
Unscr ew thefilling hose from theva lve of the
defective tyre. #
Stow th e tyre sealant bottle and the tyre
inflation compressor. #
Pull away immediatel y. #
Stop driving af ter appro ximately ten minu tes
and check the tyre pressure using the tyre
inflation compressor.
The tyre pressure must now be at least
13 0 kPa (1.3 bar/19 psi). &
WARNING Risk of accident due tothe
specified tyre pressure not being
attained
If th e specified tyre pressure is not reached,
th e tyre is too badly damaged. The tyre seal‐
ant cannot repair the tyre in this ins tance.
The braking and driving characteristics may
be great lyimpaired. #
Do not continue driving. #
Consult a qualified specialist workshop. Countries
that ha veMercedes-Benz
Service24h: you will find a sticke r with thete le‐
phone number, e.g. on the B‑pillar on the driver's
side. #
Cor rect the tyre pressure if it is still at least
13 0 kPa (1.3 bar/19 psi). See the tyre pres‐
sure table on the fuel filler flap forva lues. #
Toincrease the ty repressure: switch on
th e tyre inflation compressor. Breakdown assis
tance 395
Internal use only

&
WARNING Risk ofexplosion from hydro‐
ge nga s igniting
There is a danger of hydrogen gas igniting
when charging the battery if there is a short
circuit or spar ksstart toform. #
Make sure that the positive term inal of
th e connected battery does not come
into conta ct withvehicle parts. #
Never place me tal objects or tools on a
batter y. #
The described order of the battery
clamps must be obser ved when con‐
necting and disconnecting the batter y. #
When giving starting assis tance, al ways
make sure that you on lyconnect bat‐
te ry term inals with identical polarity. #
During starting assis tance, you must
obse rveth e described order for con‐
necting and disconnecting the jump
lead. #
Do not connect or disconnect the bat‐
te ry cla mp s while the engine is running. &
WARNING Risk ofexplosion during
ch arging process and starting assis tance
During thech arging process and starting
assis tance, the battery may release an explo‐
sive gas mixture. #
Avoid fire , naked flames, creating
spar ksand smoking. #
Make sure there is suf ficient ventila‐
tion. #
Do not lean over a batter y. &
WARNING Risk ofexplosion from a fro‐
zen battery
A dischar ged battery may freeze at temp era‐
tures slightly abo veor below freezing point.
During starting assis tance or battery charg‐
ing, bat tery gas can be released. #
Alw ays allow a battery tothaw before
ch arging it or per form ing starting assis‐
ta nce. If
th e indicator/warning lamps in the instrument
clus ter do not light up at low temp eratures, it is
ve ry likely that the dischar ged battery has fro‐
zen. In this case you may neither jump-s tart the
ve hicle nor charge the batter y.
The service life of a battery that has been
th awe d may be dramatically shor tened. The
st arting characteristics may be impaired, espe‐
cially at low temp eratures.
It is recommended that you ha veathaw ed bat‐
te ry checked at a qualified specialist workshop.
Plug-in hybrid: be sure toobser vethe no tes in
th e Supplement. You could otherwise failto rec‐
ognise dangers.
All vehicles
* NO
TEDama gecaused bynumerous or
ex tended attempt sto start the engine Nume
rous or extended attempt sto start the
engine may damage the catalytic con verter
due tonon-combu sted fuel. #
Avoid numerous and extended attem pts
to start the engine. Breakdown assis
tance 399
Internal use only