ECU MERCEDES-BENZ C-CLASS SALOON 2012 Service Manual

#
When leaving theve hicle, alw aysta ke
th eke y with you and lock theve hicle. #
Keep theve hicle key out of there ach of
ch ildren. *
NO
TEDama getotheve hicle due toit
ro lling away #
Alw ays secure theve hicle against roll‐
ing away. *
NO
TEDama gedue totheve hicle lo wer‐
ing Ve
hicles with AIRMATIC or le vel control:
The vehicle can lo wer because of temp era‐
ture dif fere nces or longer non-operational
times. This can cause dama getoparts of the
body. #
When stopping theve hicle and when
driving off, make sure that there are no
obs tacles su chas curbs under or in the
immediate vicinity of the body. #
Bring theve hicle toast andstill bypressing
th e brake pedal. #
On gradients, turn the front wheels so that
th eve hicle will rollto wa rdsth eke rb if it
st arts moving. #
App lythe electric parking brake. #
Enga getransmission position jin a station‐
ary vehicle with the brake pedal applied
(/ page 169). #
Switch off the engine and the ignition by
pressing the1 button. #
Release the service brake slowl y. #
Get out of theve hicle and lock it.
% When you park theve hicle, you can still
operate the side windo wsand the sliding
sunroof for appro ximately four minutes if the
driver's door is closed.
% When you park theve hicle, you can still
operate the side windo wsand the panoramic
sliding sunroof for appro ximately four
minutes if the driver's door is closed. Driving and parking
17 9
Internal use only

%
The electric parking brake is only securely
applied if the indicator lamp is lit continu‐
ously.
Re leasing #
Swit chon the ignition. #
Pull handle 1.
The red! indicator lamp in the instru‐
ment clus ter goes out.
Emer gency braking #
Press and hold handle 1.
As long as theve hicle is driving, theRelease
parking brake message is displa yed and the
re d! indicator lamp flashes.
When theve hicle has been braked to a
st andstill, the electric parking brake is
applied. The red! indicator lamp lights
up in the instrument clus ter. Information on collision de
tection on a
pa rked vehicle If a collision is de
tected when theto w- aw ay pro‐
te ction is primed on a loc kedve hicle, you will re
cei vea notification in the multimedia sy stem
when you swit chon the ignition.
Yo u will recei veinformation about thefo llowing
points:
R The area of theve hicle that may ha vebeen
damaged.
R The forc e of the impact.
The following situations can lead toinadver tent
acti vation:
R The pa rked vehicle is mo ved, e.g. in a two-
st or ey garage.
% Deactivate tow- aw ay protection in order to
pr eve nt inadver tent acti vation. If you deacti‐
va te tow- aw ay protection, collision de tection
will also be deactivated.
Sy stem limits
De tection may be restricted in thefo llowing sit‐
uations:
R theve hicle is damaged without impact, e.g. if
an outside mir ror is torn off or the paint is
damaged byakey
R an impact occurs at low speed R
the electric parking brake is not applied Note
s on parking up theve hicle If
yo u lea vetheve hicle par ked up for longer than
six weeks, it may suf fer dama gethro ugh disuse.
The 12V battery may also be impaired or dam‐
aged byheavy discharging.
% Further information can be obtained at a
qu alified specialist workshop.
* NO
TEPlug-in hybrid #
Obser vethe no tes about the high-volt‐
age battery in the Supplement. Yo u
could otherwise failto recognise dan‐
ge rs. St
andby mode (extension of the star ter bat‐
te ry 's period out of use) St
andby mode function
% This function is not available for all models. 184
Driving and pa rking
Internal use only

Ac
tivating/deactivating the HOLD function &
WARNING Risk of an accident due tothe
HOLD function being active when you
lea vetheve hicle
If th eve hicle is only braked with the HOLD
function it could, in thefo llowing situations,
ro llaw ay:
R Ifth ere is a malfunction in the sy stem or
in the po wer supply.
R Ifth e HOLD function is deactivated by
depressing the accelerator pedal or brake
pedal, e.g. byave hicle occupant. #
Alw ays secure theve hicle against roll‐
ing away before you lea veit. Re
quirements:
R The vehicle is stationar y.
R The driver's door is closed or the seat belt on
th e driver's side is fastened.
R The engine is running or has been au tomati‐
cally switched off bythe ECO start/ stop
function. R
The electric parking brake is released.
R Active Dis tance Assi stDISTRONIC is deacti‐
va ted.
R The transmission is in position h,kori.
Ac tivating the HOLD function #
Dep ress the brake pedal, and af ter a short
time quickly depress fur ther until theë
display appears in the multifunction displa y. #
Release the brake pedal.
Deactivating the HOLD function #
Depress the accelerator pedal topull away.
or #
Depress the brake pedal until theë dis‐
play disappears from the multifunction dis‐
pla y.
The HOLD function is deactivated in thefo llow‐
ing situations:
R Active Dis tance Assi stDISTRONIC is acti va‐
te d.
R The transmission is shif tedto position j. R
The vehicle is secured with the electric park‐
ing brake.
In thefo llowing situations, theve hicle is held by
transmission position jand/or bythe electric
parking brake:
R The seat belt is unfas tened and the driver's
door is opened.
R The vehicle is switched off.
R There is a malfunction in the sy stem or the
po we r supp lyis insuf ficient. Fu
nction of Hill Start Assist Hill
Start Assist holds theve hicle for a short
time when pulling away on a hill under thefo l‐
lowing conditions:
R Vehicles with automatic transmission: the
transmission is in position hork.
R The electric pa rking brake is released.
This gives you enough time tomo veyour foot
from the brake pedal tothe accelera tor pedal
and depress it before theve hicle begins toroll
aw ay. Driving and pa
rking 191
Internal use only

&
WARNING Risk of accident and inju ry
due totheve hicle rolling away
Af ter a short time, Hill Start Assist no lon ger
holds theve hicle. #
Swiftly mo veyour foot from the brake
pedal tothe accelera tor pedal. Do not
lea vetheve hicle when it is being held
by Hill Start Assist. Fu
nction of Adaptive Brake Lights Ad
aptive Brake Lights warnfollowing traf fic in an
emergency braking situation with th efo llowing
actions:
R Byflashing the brake lamps
R By activating the hazard warning lights
If th eve hicle is braked sharply from speeds
abo ve50 km/h, the brake lamps flash rapidl y.
This pr ovides traf fic tr avelling behind you with an
ev en more noticeable warning.
If th eve hicle is tr avelling at speeds of more than
70 km/h at the beginning of the brake applica‐
tion, the hazard warning lights switch on once th
eve hicle is stationar y.When you pull away
again, the hazard warning lights will switch off
automatically at appr oximately 10km/h. Yo u
can also switch off the hazard warning lights
using the hazard warning button. AT
TENTION ASSI ST Fu
nction of ATTENTION ASSI ST
AT TENTION ASSIST assists you on long, mon oto‐
nous jou rney s, e.g. on mo torw ays and trunk
ro ads. If ATTENTION ASSIST de tects indicators
of fatigue or increasing lapses in concentration
on the part of the driver, it suggests taking a
brea k.
AT TENTION ASSIST is only an aid. It cannot
alw ays de tect fatigue or lapses in concentration
in time. The sy stem is not a substitute for a well-
re sted and attentive driver. On long journe ys,
ta ke regular breaks in good time that allow for
adequate recuperation.
Yo u can choose between two settings:
R Standard: normal sy stem sensitivity. R
Sensitive: higher system sensitivity. The
driver is warned earlier and the attention
le ve l de tected byATTENTION ASSIST is adap‐
te d accordingly.
If dr owsiness or inc reasing lapses in concentra‐
tion are de tected, theATTENTION ASSIST: Take
a break! warning appears in the Instrument Dis‐
pla y.Yo u can ackn owledge the message and
ta ke a break where necessar y.Ifyo u do not take
a break and ATTENTION ASSIST continues to
de tect increasing lapses in concentration, you
will be warned again af ter a minimum of
15 minutes. 19 2
Driving and pa rking
Internal use only

&
WARNING Risk of an accident due to
Ac tive Dis tance Assi stDISTRONIC being
acti vewhen you lea vethe driver's seat
If yo u lea vethe driver's seat while theve hicle
is being braked byActive Dis tance Assi st
DISTRONIC only, theve hicle can rollaw ay. #
Alw ays deactivate Active Dis tance
Assi stDISTRONIC and secure theve hi‐
cle topreve nt it from rolling away
before you lea vethe driver's seat. #
Select Owiththe left rock er switch.
% Ifyo u brake, deactivate ESP ®
or if ESP ®
inter venes, Active Dis tance Assi st
DISTRONIC is deacti vated.
Increasing/decreasing thesto red speed #
1 km/h: press rocker switch 1upM or
down Ntothe pressure point, or press
and hold (increments of 1 km/h).
or #
10km/h: press rock er switch 1upM or
down Nbeyond the pressure point, or
press and hold (increments of 10km/h).
or #
Accelerate theve hicle tothe desired speed
and press rocker switch 1upM.
Changing the specified distance totheve hi‐
cle in front #
Toreduce the speci fied distance: press
th eright rock er switch up (Ñ). #
Toincrease the specified distance: press
th eright rock er switch down (Ò).
Fu nction of Active Speed Limit Assi st
If speed limit change between 20 km/h and
13 0 km/h is de tected and the automatic adop‐
tion of speed limits is active, it will be automati‐
cally adop ted as thestored speed
(/ page 212).
The driven speed is adju sted when theve hicle is
le ve l with the traf fic sign at the latest. In the
case of signs indicating entry into an urban area,
th e speed is adap ted according tothe speed
permitted within the urban area. The speed limit display in
the Instrument Display is alw ays upda‐
te d when theve hicle is le vel with the tra ffic sign.
If th ere is no speed restriction on an unlimited
st re tch of road (e.g. on a mo torw ay),th ere com‐
mended speed is auto maticallyadop ted as the
st ored speed. The sy stem uses the speed stored
on an unlimited stre tch of road as there com‐
mended speed. If you do not alter thestored
speed on an unlimited stre tch of road, there c‐
ommended speed is 130 km/h.
If Ac tive Dis tance Assi stDISTRONIC has been
put into passi vemode bypressing the accelera‐
to r pedal, only speed limits which are higher
th an the set speed are adop ted.
Obser vethe no tes on driving sy stems and your
re sponsibility; you may otherwise failto recog‐
nise dangers (/ page 185).
Sy stem limits
The sy stem limits of Traf fic Sign Assi stapply to
th e de tection of traf fic signs (/ page 211).
Speed limits bel ow20 km/h are not auto mati‐
cally adop tedby the sy stem as thestored speed.
Te mp orary speed restrictions (e.g. for a cer tain
time or due towe ather conditions) cannot be Driving and parking
201
Internal use only

Fu
nction of Active Eme rgency Stop Assist If
th e sy stem de tects that the driver has not
st eered theve hicle for a considerable period of
time or has remo vedth eir hands from thesteer‐
ing wheel, display 1appears in the multifunc‐
tion displa y.Ifth e driver still does not steer the
ve hicle, or gives no confirmation tothe sy stem,
a wa rning tone sounds in addition tothe visual
wa rning message.
If th e driver still does not respond tothewa rn‐
ing, theBeginning emergency stop message
appears in the multifunction displa y.Ifth e driver
st ill does not respond, Active Dis tance Assi st DISTRONIC
reduces the speed. The vehicle is
decelerated in stages toast andstill.
Depending on the count ry, at speeds below
60 km/h the hazard warning lights switch on
automaticall y.
When theve hicle is stationar y,thefo llowing
actions are car ried out:
R The vehicle is secured with the electric park‐
ing brake.
R Active Dis tance Assi stDISTRONIC is ended
R The vehicle is unloc ked.
R If possible, an emer gency call is placed to
th e Mercedes-Benz emer gency call centre
The driver can cancel the deceleration at any
time byper form ing one of thefo llowing actions:
R Steering
R Braking or accelerating
R Deactivating Active Dis tance Assi st
DISTRONIC Ac
tive Brake Assi st Fu
nction of Active Brake Assi st
Ac tive Brake Assi stconsi sts of thefo llowing
functions:
R Distance warning function
R Autonomous braking function
R Situation-dependent braking assi stance
R Vehicles with Driving Assistance Pack‐
age: Evasi veSteering Assist and cornering
function
Ac tive Brake Assi stcan help youto minimise the
ri sk of a collision with vehicles, cyclists or
pedestrians or toreduce the ef fects of such a
collision.
If Ac tive Brake Assi sthas de tected a risk of colli‐
sion, a warning tone sounds and theL dis‐
ta nce warning lamp lights up in the instrument
clus ter.
If yo u do not react tothewa rning, autonomous
braking can be initiated in critical situations.
In especially critical situations, Active Brake
Assi stcan initia teautonomous braking direct ly.206
Driving and parking
Internal use only

#
Alw ays engage the ball neck as descri‐
bed. &
WARNING Risk of injury from ball neck
swinging outwards
The ball neck may swing outwards when
unlo cking or when it has not been properly
engaged.
There is a risk of injury within the ball neck's
ra nge of mo vement! #
Unlock the ball neck only when its
ra nge of mo vement is unobstructed. #
Alw ays be sure the ball neck is engaged
when folding in wards. Re
quirements:
R The vehicle is secured against rolling away.
R The swivel range is clear.
R The trailer cables or adap ter plugs ha vebeen
re mo ved. Fo
lding the ball neck out #
Pull switch 2until the ball neck unloc ks.
The ball neck will fold out from under the
re ar bumper.
Indicator lamp 1will flash. #
Pull the ball neck in the direction of the
ar row until it en gage s audibly in a vertical
position.
Indicator lamp 1onthe ball neck release
switch will go out.
If th e ball neck is not securely loc ked in
place, theCheck trailer hitch lock message
will appear on the multifunction displa y.238
Driving and parking
Internal use only

#
Remo vethe co ver cap from the ball head and
st ore it in a safe place.
Make sure that the ball on the ball neck is clean.
Check that it is either greased or dr y (grease-
free), depending on the instructions forthe
traile r.
Fo lding the ball neck in #
Pull swit ch2 until the ball neck unloc ks.
The ball neck will fold up under there ar
bumper.
Indicator lamp 1will flash. #
Push the ball neck in the direction of the
ar row until it en gage s audibly behind the
bumper.
Indicator lamp 1will go out and the mes‐
sage on the multifunction display will disap‐
pear.
Obser vethe information about the displa yson
th e instrument clus ter:
R Indicator and warning lamps (/ page 498)
R Display messages (/ page445) Coupling/uncoupling a trailer
&
WARNING Risk of injury fromtheve hicle
le ve l being changed
Ve hicles with le vel control sy stem: the
ve hicle le vel may be changed unin tentional ly,
e.g. by ot her persons. You may become trap‐
ped if you couple up or uncouple a trailer
while theve hicle le vel is changing. In addi‐
tion, other people could become trapped if
th eir limbs are between theve hicle body and
th e tyres or underneath theve hicle.
When coupling up or uncoupling a trailer,
make sure that: #
The doors or tailgate are not opened or
closed. #
You do not initiate the le vel control sys‐
te m and do not operate theDY NA MIC
SELECT switch. #
Do not lock or unlock theve hicle. Re
quirements:
R The ball neck is extended and engaged in a
secu rely loc ked position. Tr
ailers with a 7-pin plug can be connec tedto
th eve hicle with thefo llowing adap ters:
R Adapter plug
R Adapter cable
The trailer will be cor rectly de tected bytheve hi‐
cle only if thefo llowing conditions are me t:
R The trailer is connected cor rectl y.
R The trailer lighting sy stem is in working
order.
The functions of thefo llowing sy stems will be
af fected bya cor rectly connected trailer:
R ESP ®
trailer stabilisation
R Active Lane Keeping Assist
R Parking Assist PARKTRONIC
R Active Parking Assist
R Blind Spot Assist or Active Blind Spot Assi st
R Drive AwayAssi st
R Cross Traf fic Alert
R Reversing camera
R 360° camera Driving and parking
239
Internal use only

R
AIRMATIC
Coupling up a trailer
* NO
TEDama getothest ar ter battery due
to full dischar ge Charging
the trailer battery using the po wer
supply of the trailer can damage thest ar ter
batter y. #
Do not use theve hicle's po wer supply
to charge the trailer batter y.#
Remo vethe co ver cap from the ball head and
st ore it in a safe place. #
Position the trailer on a le vel sur face behind
th eve hicle and couple it up totheve hicle. #
Open the soc ket cap. #
Inse rtthe plug with lug 1in groo ve3 on
th e soc ket. #
Turn bayonet coupling 2totheright as far
as it will go. #
Let the cap engage. #
Secure the cable tothe trailer with cable ties
(only if you are using an adap ter cable). #
Make sure that the cable is alw ays slack for
ease of mo vement during cornering. Under
thefo llowing conditions, a message may
appear on the multifunction display even if the
trailer has been connected cor rectly:
R LEDs ha vebeen ins talled in the trailer light‐
ing sy stem.
R The cur rent has fallen below the trailer light‐
ing sy stem's minimum cur rent (50 mA).
% Accessories can be connected tothe perma‐
nent po wer supp lyup to180 W and tothe
po we r supp lythat is swit ched on via the igni‐
tion loc k.
Un coupling a trailer &
WARNING Risk of being crushed and
becoming trapped when uncoupling a
trailer
When uncoupling a trailer with an engaged
ine rtia-activated brake, your hand may
become trapped between theve hicle and the
trailer dr awbar. #
Do not uncouple trailers with an
engaged overrun brake. 240
Driving and pa rking
Internal use only

*
NO
TEDama gewhen uncoupling in a
st ate of overrun Uncou
pling in a state of overru n can dama ge
th eve hicle. #
Do not uncouple trailers with an
engaged overrun brake. &
WARNING Risk of becoming trapped
when disconnecting the trailer cable
Ve hicles with le vel control sy stem: The
ve hicle may lo wer when the trailer cable is
disconnected.
This could result in you or other people
becoming trapped if your or their limbs are
between theve hicle body and the tyres or
underneath theve hicle. #
Make sure that nobody is unde rneath
th eve hicle or in the immediate vicinity
of the wheel ar ches when you discon‐
nect the trailer cable. #
Secure the trailer against rolling away. #
Disconnect the electrical connection
between theve hicle and the trailer. #
Uncouple the trailer. #
Place the co ver cap on the ball head. Bicycle
rackfunction &
WARNING Risk of an accident when
using the bicycle rack incor rectly
The bicycle rack may become de tach ed from
th eve hicle in thefo llowing cases:
R the permissible load capacity of the
trailer hitch is exceeded.
R the bicycle rack is used incor rectl y.
R the bicycle rack is secured tothe ball
neck beneath the ball head.
Obser vethefo llowing foryo ur ow n sa fety
and that of other road users: #
always adhere tothe permissible load
capacity of the trailer hitch. #
only use the bicycle rack totranspo rt
bicycles. #
always proper lysecure the bicycle rack
by attaching it tothe ball head. #
only use bicycle rack s appr ovedby
Mercedes-Benz. #
always obser vethe bicycle rack operat‐
ing instructions. *
NO
TEDama geto, or cra cks on, the
trailer hitch due tounsuitable bic ycle
ra ck s or bicycle rack s being used incor‐
re ctly #
use only bicycle rack s appr ovedby
Mercedes-Benz. Driving and parking
241
Internal use only