ECU MERCEDES-BENZ C-CLASS SALOON 2012 Repair Manual

#
Push bo thsides of warning triangle holder
1 inthe direction of the ar row and open it. #
Remo ve wa rning triangle 2.
Setting up thewa rning triangle #
Fold side reflectors 1upwards toform a tri‐
angle and attach at theto p using upper
press-stud 2. #
Fold legs 3down and out tothe side. Fi
rs t-aid kit (soft-sided) overview Fir
st-aid kit (so ftsided) 1is in the boot in the
left-hand or right-hand stowage net, depending
on the model. Re
moving the fire extinguisher &
WARNING Risk of accident due toan
incor rectly secu redfire extinguisher in
th e driver's foot we ll
A fire extinguisher may impede pedal tr avel
or block a depressed pedal.
This jeopardises the operating and road
saf ety of theve hicle.
The fire extinguisher can be flung around and
injure the driver or other vehicle occupants. #
Alw aysst ore and secure thefire extin‐
guisher in the brac ket. #
Do not remo vethefire extinguisher
while driving. Breakdown assi
stance 389
Internal use only

Obser
vethefo llowing points during starting
assis tance and when charging the battery:
R Only use undamaged jump lead/charging
cables with a suf ficient cross-section and
insula tedte rm inal clamps.
R Non- insulated parts of thete rm inal clamps
must not come into con tact wi thother me tal
parts while the jump lead/charging cable is
connected tothe battery/jump-s tart connec‐
tion point.
R The jump lead/charging cable must not
come into contact wi thany parts which may
mo vewhen the engine is running.
R Alw ays make sure that nei ther you nor the
battery is elect rostatically charge d.
R Keep away from fire and naked flames.
R Do not lean overth e batter y.
Obser vethe additional following points when
ch arging the battery:
R Only use battery charge rs tested and
appr oved for Mercedes-Benz.
R Read the battery charge r's operating instruc‐
tions before charging the batter y. Obser
vethe additional following points during
st arting assis tance:
R Starting assis tance may only be pr ovided
using vehicles, batteries or other jump start
devices with a nominal voltage of 12V.
R The vehicles must not touch.
R Vehicles with a petrol engine: jump-start
th eve hicle only when the engine and exhaust
sy stem are cold. St
arting assi stance and charging the12 V
battery Preparing
starting assi stance/charging #
Secure theve hicle byapplying the electric
parking brake. #
Automatic transmission: shiftthe trans‐
mission toposition j. #
Manual transmission: shiftthe transmis‐
sion toneutral. #
Switch off the ignition and all electrical con‐
sumers. #
Open the bonn et. #
Fold co ver1 up in the direction of the
ar row. 400
Breakdown assis tance
Internal use only

*
NO
TEDama gedue toexcessive tracti ve
po wer If
yo u pull away sharpl y,the tractive po wer
may be too high and theve hicles could be
damaged. #
Pull away slowly and smoo thly. Loading the
vehicle for transport #
Obser vethe no tes on towing away
( / page 403). #
Connect theto w bar totheto wing eye in
order toload theve hicle.
% You can also attach theto w bar tothe trailer
hitch. #
Vehicles with automatic transmission:
shift the automatic transmission toposition
i.
% Ve
hicles with automatic transmission:
th e automatic transmission may be loc ked in
position jintheeve nt of damage tothe
electrical sy stem. Toshift toi , pr ovide the on-board electrical sy
stem with po wer
( / page 400). #
Load theve hicle onto the transpor ter. #
Vehicles with automatic transmission:
shift the automatic transmission toposition
j. #
Use the electric parking brake tosecure the
ve hicle against rolling away. #
Only secure theve hicle bythe wheels.
Ve hicles with ADS PLUS (Adaptive Damping
Sy stem PLUS) &
WARNING Risk of an accident when
transporting vehicles with Adaptive
Damping Sy stem PLUS
When transporting vehicles with Adaptive
Damping Sy stem PLUS, theve hicle/trailer
combination may begin torock andstart to
skid. #
When transporting, ensure that:
R theve hicle has been loaded onto
th e transpor ter cor rectly R
theve hicle is secured at all four
wheels with suitable tensioning
st ra ps
R the maximum permissible speed of
60 km/h is not exceeded when
transporting *
NO
TEDama getotheve hicle from secur‐
ing it incor rectly #
After loading, theve hicle must be
secured on all four wheels. Otherwise,
th eve hicle could be damaged. #
A minimum dis tance of 20 cm up wards
and 10cm down wards must be kept to
th e transport platform. #
Secure theve hicle on all four wheels af ter
loading. Breakdown assis
tance 405
Internal use only

To
w starting theve hicle (eme rgency engine
st art) Ve
hicles with automatic transmission
* NO
TEDama getothe automatic trans‐
mission due to tow-starting The automatic transmission may be damaged
in
the process of tow- starting vehicles with
automatic transmission. #
Vehicles with automatic transmission
must not be tow- star ted. #
Vehicles with automatic transmission must
not be tow- star ted. Electrical fuses
Note
s on electrical fuses &
WARNING Risk of accident and inju ry
due to ov erloaded lines
If yo u manipulate or bridge a faulty fuse or if
yo ure place it with a fuse with a higher amperage,
the electric line could be overloa‐
ded.
This could result in a fire. #
Alw aysre place faulty fuses with speci‐
fi ed new fuses conta iningthe cor rect
amperage. *
NO
TEDama gedue toincor rect fuses Electrical components or sy
stems may be
damaged byincor rect fuses, or their func‐
tionality may be significant lyimpaired. #
Only use fuses that ha vebeen appr oved
by Mercedes-Benz and which ha vethe
cor rect fuse rating. Blown fuses mu
stbe replaced with fuses of the
same rating, which you can recognise bythe col‐
our and the labelling. The fuse ratings and fur‐
th er information tobe obser ved can be found in
th e fuse assignment diagram.
Fu se assignment diag ram: onthe fuse box in
th e boot (/ page 409). *
NO
TEDama geor malfunctions caused
by moisture Moisture may cause dama
getothe electrical
sy stem or cause it tomalfunction. #
When the fuse box is open, make sure
th at no moisture can enter the fuse
box. #
When closing the fuse box, make sure
th at the seal of the lid is positioned cor‐
re ctly on the fuse box. If
th e newly inser ted fuse also blo ws, ha vethe
cause traced and rectified at a qualified special‐
ist workshop.
Ensure thefo llowing before replacing a fuse:
R The vehicle is secured against rolling away.
R All electrical consumers are switched off.
R The ignition is switched off.
The electrical fuses are located in various fuse
bo xes:
R Fuse box in the engine compartment on the
driver's side (/ page 408) Breakdown assis
tance 407
Internal use only

#
Ensu rethat the wheel bolts or wheel
nuts are tightened tothe prescribed
tightening torque. #
Ifyo u are not sure, do not mo vethe
ve hicle. Contact a qualified specialist
wo rkshop and ha vethe tightening tor‐
qu ech ecked immediately. #
Check the tyre pressure of the newly fitted
wheel and adjust it if necessa ry.#
Vehicles with a tyre pressure monitoring
sy stem: restart the tyre pressure monitoring
sy stem (/ page413).
Excep tion:the new wheel is an emer gency
spa rewheel. Emer
gency spare wheel Note
s onthe emer gency spare wheel &
WARNING Risk of accident caused by
incor rect wheel and tyre dimensions
The wheel or tyre size and the tyre type of
th e emer gency spa rewheel or spare wheel
and the wheel tobe replaced may dif fer. The
emer gency spa rewheel or spare wheel can
significantly impair driving characteristics of
th eve hicle.
To preve nt hazardous situations: #
Drive carefully. #
Neverfit more than one emer gency
spa rewheel or spare wheel that dif fers
in size. #
Only use an emer gency spa rewheel or
spare wheel brief ly. #
Do not deacti vate ESP ®
. #
Have the emer gency spa rewheel or
spare wheel of a dif fere nt size replaced
at the nearest qualified specialist work‐ shop. The new wheel must ha
vethe
cor rect dimensions. %
The emergency spa rewheel is secured in the
emer gency spa rewheel bag in the boot.
Obser vethefo llowing no tes on fitting an emer‐
ge ncy spa rewheel:
R Check the tyre pressure of the emer gency
spa rewheel fitted. Co rrect the pressure as
necessar y.
R The maximum permissible speed with an
emer gency spa rewheel fitted is 80 km/h.
R Do not fit th e emer gency spa rewheel with
sn ow ch ains.
R Replace the emer gency spa rewheel af ter six
ye ars at the latest, rega rdless of wear. 424
Wheels and tyres
Internal use only

Display messages
Possible causes/consequences and M
MSolutions &
WARNING Risk of injury or death when using a child restra int sy stem while the front passenger airbag is
enabled
If yo u secure a child in a child restra int sy stem on the front passenger seat and the front passenger airbag is
enabled, the front passenger airbag can deploy in theeve nt of an accident.
The child could be stru ck bythe airbag. #
Ensure, bo thbefore and during the journe y,that thest atus of the front passenger airbag is cor rect.
NEVER use a rear wa rdfacing child restra int on a seat pr otected byan ACTIVE AIRB AGin front of it, DE ATH or
SERIOUS INJU RYtotheCH ILD can occur. #
Stop theve hicle immediately in accordance with the traf fic conditions. #
Makesure that no objects are trapped under the front passenger seat. #
Check thest atus of automatic front passenger airbag actuation (/ page 48).#
If necessar y,consult a qualified specialist workshop immediatel y.
PRE-SAFE inoperative See
Owner's Manual *
The PRE‑SAFE ®
functions are malfunctioning. #
Consult a qualified specialist workshop. 448
Displaymessa ges and warning/indicator lamps
Internal use only

Ve
hicle Display messages
Possible causes/consequences and M
MSolutions
d Vehicle is operational
Switch off ignition before
exiting *Y
ou are leaving theve hicle in a ready-to-drive state. #
When you lea vetheve hicle, switch off the ignition, secure theve hicle against rolling away and take theke y with
yo u. #
Ifyo u do not lea vetheve hicle, switch off the electrical consumers, e.g. the seat heating. Otherwise, the12 V
battery may dischar geand it will then be possible tostart theve hicle only with the aid of a second battery
(s ta rting assis tance).
ï Check trailer hitch lock *T
he trailer hitch is not operational during a journey with a trailer. &
WARNING Risk of an accident if the ball neck is not loc ked
The trailer may become de tach ed. #
Stop theve hicle immediately in accordance with the traf fic conditions. Do not continue driving. #
Uncouple the trailer and secure it against rolling away. #
Initiate a new swivel mo vement and do not re-couple the trailer until thewa rning/indicator lamp goes out. #
Initiate a new swivel mo vement (/ page 237). #
When the display message disappears, couple up the trailer and drive on.
If th e display message does not disappear, the trailer hitch is malfunctioning and the ball neck is not loc ked. 456
Display messages and warning/indicator lamps
Internal use only

Display messages
Possible causes/consequences and M
MSolutions #
Do not couple up the trailer. Drive on without the trailer. No tethere duced ground clearance due tothe
unlo cked ball nec k. #
Consult a qualified specialist workshop.
*T he trailer hitch will not be operational when theve hicle is stationar y. #
Uncouple the coupled trailer and secure it against rolling away. #
Ifth e ball neck has been folded in: unlockthe ball neck (/ page 237). #
Swivel the ball neck into the end position manually and let it engage. #
Ifth e ball neck has been folded out: unlockthe ball neck (/ page 237). #
Swivel the ball neck beneath the bumper manually and let it engage.
If th e display message does not disappear, the trailer hitch is malfunctioning and the ball neck is not loc ked. #
Do not couple up the trailer. Drive on without the trailer. No tethere duced ground clearance due tothe
unlo cked ball nec k. #
Consult a qualified specialist workshop.
Ù Steering malfunction
Increased physical effort
See Owner's Manual *T
he po werst eering assis tance is malfunctioning. &
WARNING Risk of an accident due toaltered steering characteristics
If th e po wer assi stance of thesteering fails partially or comple tely, you will need touse more forc eto steer. #
If safe steering is possible, drive on carefully. Display messages and
warning/indicator lamps 457
Internal use only

Display messages
Possible causes/consequences and M
MSolutions
Auxiliary battery malfunc-
tion *T
he auxiliary batteryforth e transmission is no longer being charge d. #
Consult a qualified specialist workshop. #
Untilthen, alw ays select park position jmanually before you swit choff the engine. #
Before leaving theve hicle, apply the electric parking brake. Brakes
Display messages
Possible causes/consequences and M MSolutions
! Parking brake See Owner's
Manual *
The yellow ! indicator lamp is lit. The elect ric pa rking brake is malfunctioning.
To appl y: #
Switch the ignition off and switch it back on. #
Apply the electric parking brake manually (/ page183).
If it is not possible toapply the electric parking brake: #
Consult a qualified specialist workshop. #
Where necessar y,also secure the par kedve hicle against rolling away.
* The yellow ! indicator lamp and there d! indicator lamp are lit. The elect ric pa rking brake is malfunction‐
ing.
To release: Display messages and
warning/indicator lamps 465
Internal use only

Display messages
Possible causes/consequences and M
MSolutions #
Switch the ignition off and switch it back on. #
Release the electric parking brake manually (/ page183).
or #
Release the electric parking brake automatically (/ page183).
If it is still not possible torelease the electric parking brake: #
Do not continue driving. Consult a qualified specialist workshop.
* The yellow ! indicator lamp is lit and there d! indicator lamp is flashing. The electric parking brake is mal‐
functioning.
The electric parking brake could not be applied or released. #
Swit chthe ignition off and switch it back on.
To appl y: #
Release and then apply the electric parking brake manually (/ page183).
To release: #
Apply and then release the electric parking brake manuall y.
If it is not possible toapply the electric parking brake or there d! indicator lamp continues toflash: #
Do not continue driving. Consult a qualified specialist workshop. #
Where necessar y,also secure the par kedve hicle against rolling away. 466
Display messages and warning/indicator lamps
Internal use only