Sensors MERCEDES-BENZ C-Class SEDAN 2012 W204 Owner's Manual

CareCarpets .......................................... 289
Car wash ........................................ 284
Display ........................................... 288
Exterior lights ................................ 287
Gear or selector lever ....................288
Matte finish ................................... 285
Notes ............................................. 283
Paint .............................................. 285
Plastic trim .................................... 288
Power washer ................................ 284
Rear view camera .......................... 287
Roof lining ...................................... 289
Seat belt ........................................ 289
Seat cover ..................................... 288
Sensors ......................................... 287
Steering wheel ............................... 288
Tail pipes ....................................... 287
Trim pieces .................................... 288
Washing by hand ........................... 284
Wheels ........................................... 285
Windows ........................................ 286
Wiper blades .................................. 286
Wooden trim .................................. 288
Cargo tie down rings ......................... 258
Car wash (care) ................................. 284
CD player/CD changer (on-board
computer) .......................................... 202
Cell phone see Mobile phone
Center console ..................................... 32
Central locking Automatic locking (on-board
computer) ...................................... 208
Locking/unlocking (SmartKey) ........70
Changing bulbs
Brake lamps ................................... 116
Cornering light function .................115
High-beam headlamps ...................115
Important safety notes ..................113
Low-beam headlamps ....................114
Overview of bulb types ..................114
Parking lamps ................................ 115
Reversing lamps ............................ 116
Standing lamps (front) ...................115
Child-proof locks
Important safety notes ....................57
Rear doors ....................................... 57Children
In the vehicle ................................... 53
Restraint systems ............................ 53
Child seat
LATCH-type (ISOFIX) child seat
anchors ............................................ 55
Special seat belt retractor ...............55
Top Tether ....................................... 56
Cigarette lighter ................................ 262
Climate control Automatic climate control (3-
zone) .............................................. 125
Controlling automatically ...............127
Cooling with air dehumidification ..126
Defrosting the windows .................130
Defrosting the windshield ..............129
Dual-zone automatic climate
control ........................................... 123
Important safety notes ..................122
Indicator lamp ................................ 127
Maximum cooling .......................... 130
Notes on using automatic climate
control ................................... 124, 126
Overview of systems ......................122
Problems with cooling with air
dehumidification ............................ 127
Problem with the rear window
defroster ........................................ 130
Rear control panel .........................125
Refrigerant ..................................... 350
Setting the air distribution .............128
Setting the airflow .........................129
Setting the air vents ......................131
Setting the climate mode (AIR
FLOW) ............................................ 127
Setting the temperature ................128
Switching air-recirculation mode
on/off ............................................ 130
Switching on/off ........................... 126
Switching residual heat on/off ......131
Switching the rear window
heating on/off ............................... 130
Switching the ZONE function on/
off .................................................. 129
Cockpit
Overview .......................................... 28
see Instrument cluster 6Index

Position of exterior mirror, front-
passenger side ............................... 102
Rear view camera .......................... 181
see PARKTRONIC
Parking aid
Parking Guidance ........................... 178
see Exterior mirrors
see PARKTRONIC
Parking brake
Display message ............................ 216
Notes/function .............................. 154
Parking Guidance
Display message ............................ 230
Important safety notes ..................178
Parking lamps (changing bulbs) ...... 115
PARKTRONIC Deactivating/activating .................177
Driving system ............................... 175
Function/notes ............................. 175
Problem (malfunction) ...................178
Range of the sensors .....................176
Warning display ............................. 177
PASSENGER AIR BAG OFF indicator
lamp ...................................................... 42
Pedals ................................................. 155
Permanent four-wheel drive see 4MATIC (permanent four-
wheel drive)
Plastic trim (cleaning instructions) . 288
Power washers .................................. 284
Power windows see Side windows
PRE-SAFE ®
Brake (vehicles with
DISTRONIC PLUS) Display message ............................ 218
Function/notes ................................ 65
Switching on/off ........................... 205
Warning lamp ................................. 249
Preventive occupant safety
system
see PRE-SAFE ®
(Preventive
occupant safety system)
Product information ............................ 21
Program selector button .................. 144
Pulling away Automatic transmission .................139Q
Qualified specialist workshop ........... 24
R
RACE START (AMG vehicles) ............. 174
RACETIMER (on-board computer) .... 211
Radar sensor system Activating/deactivating .................208
Display message ............................ 229
Radio
Selecting a station .........................201
see separate operating instructions
Reading lamp ..................................... 112
Rear compartment Setting the airflow .........................129
Setting the air vents ......................133
Rear fog lamp
Display message ............................ 223
Switching on/off ........................... 108
Rear seat
Display message ............................ 237
Folding the backrest forwards/
back ............................................... 257
Rear view camera
Cleaning instructions .....................287
Function/notes ............................. 181
Rear-view mirror
Anti-glare (manual) ........................101
Dipping (automatic) .......................102
Rear window blind ............................ 261
Rear window defroster Problem (malfunction) ...................130
Rear window heating
Switching on/off ........................... 130
Rear window wiper
Replacing the wiper blade .............. 118
Switching on/off ........................... 117
Refueling
Fuel gauge ....................................... 29
Important safety notes ..................150
Refueling process ..........................151
see Fuel
Releasing the parking lock
manually (automatic
transmission) ..................................... 149
14Index

Remote controlGarage door opener .......................270
Reporting safety defects .................... 25
Reserve (fuel tank) see Fuel
Reserve fuel
Display message ............................ 228
Warning lamp ................................. 246
see Fuel
Residual heat (climate control) ........ 131
Restraint system see SRS (Supplemental Restraint
System)
Reverse gear
Engaging (automatic
transmission) ................................. 142
Roadside Assistance (breakdown) .... 22
Roller blind see Roller sunblind
Roller sunblind
Panorama roof with power tilt/
sliding panel ..................................... 88
Rear side windows .........................261
Rear window .................................. 261
Roof carrier ........................................ 259
Roof lining and carpets (cleaning
guidelines) ......................................... 289
Roof load (maximum) ........................ 351
Route see Route guidance (navigation)
Route guidance (navigation) ............ 200
S
Safety Children in the vehicle .....................53
Child restraint systems ....................53
Occupant Classification System
(OCS) ............................................... 42
Overview of occupant safety
systems ........................................... 36
Safety systems
see Driving safety systems
Seat belts
Adjusting the height ......................... 51
Belt force limiters ............................ 52
Cleaning ......................................... 289
Correct usage .................................. 49
Emergency Tensioning Devices ........ 52
Fastening ......................................... 50
Important safety guidelines .............48
Releasing ......................................... 51
Safety guidelines ............................. 37
Special seat belt retractor ...............55
Warning lamp ................................. 239
Warning lamp (function) ................... 51
Seats
Adaptive seat backrests (AMG
vehicles) .......................................... 97
Adjusting (electrically) .....................94
Adjusting (manually and
electrically) ...................................... 94
Adjusting lumbar support ................97
Adjusting the 4-way lumbar
support ............................................ 97
Adjusting the head restraint ............95
Cleaning the cover .........................288
Correct driver's seat position ........... 92
Important safety notes ....................93
Seat heating problem ......................98
Seat ventilation problem ..................99
Storing settings (memory
function) ........................................ 103
Switching seat heating on/off .........98
Switching seat ventilation on/off ....98
Sensors (cleaning instructions) ....... 287
Service see ASSYST PLUS service interval
display
Service interval display
Displaying service messages .........283
Hiding service messages ...............283
Notes ............................................. 283
Service messages ..........................282
Service menu (on-board computer) . 206
Service products Brake fluid ..................................... 350
Capacities ...................................... 346
Coolant (engine) ............................ 350
Engine oil ....................................... 349
Fuel ................................................ 347
Important safety notes ..................344
Refrigerant (air-conditioning
system) .......................................... 350
Washer fluid ................................... 351Index15

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops ( Y page 24).
Occupant safety
Overview of occupant safety
In this section, you will learn the most
important facts about the restraint system
components of the vehicle.
The restraint system consists of:
R seat belts
R child restraint systems
R LATCH-type (ISOFIX) child seat anchors
Additional protection is provided by:
R SRS (Supplemental Restraint System)
R NECK-PRO head restraints/NECK-PRO
luxury head restraints
R Air bag system components with:
- PASSENGER AIR BAG OFF indicator lamp
- front-passenger seat with Occupant
Classification System (OCS)
The different air bag systems work
independently of each other. The protective
functions of the system work in conjunction
with each other. Not all air bags are deployed
in an accident.
GWARNING
Modifications to or work improperly
conducted on restraint system components
or their wiring, as well as tampering with
interconnected electronic systems, can lead
to the restraint systems no longer functioning
as intended.
Air bags or Emergency Tensioning Devices
(ETDs), for example, could deploy
inadvertently or fail to deploy in accidents
although the deceleration threshold for air
bag deployment is exceeded. Therefore,
never modify the restraint systems. Do not
tamper with electronic components or their
software.
i See "Children in the vehicle"
( Y page 53) for more information on
infants and children traveling with you in
the vehicle and restraints for infants and
children.
SRS (Supplemental Restraint System)
Introduction
SRS consists of:
R the 6 SRS warning lamp
R air bags
R air bag control unit (with crash sensors)
R Emergency Tensioning Devices
R belt force limiters
SRS reduces the risk of occupants coming
into contact with the vehicle's interior in the
event of an accident. It can also reduce the
effect of the forces to which occupants are
subjected during an accident.
SRS warning lamp
SRS functions are checked regularly when
you switch on the ignition and when the
engine is running. Therefore, malfunctions
can be detected in good time.
The 6 SRS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out no later than a few seconds
after the engine is started.
The SRS components are in operational
readiness when the 6 SRS warning lamp
is not lit while the engine is running .
36Occupant safetySafety

Your vehicle has adaptive, two-stage front air
bags. In the event of a collision, the air bag
control unit evaluates the vehicle
deceleration. In the first deployment stage,
the front air bag is filled with enough
propellant gas to reduce the risk of injuries.
The front air bag is fully deployed if a second
deployment threshold is exceeded within a
few milliseconds.
The deployment of the front-passenger front
air bag is also influenced by the weight
category of the front passenger, which is
determined by the Occupant Classification
System (OCS) ( Y page 42).
The lighter the passenger side occupant, the
higher the vehicle deceleration rate required
(predicted at the start of the impact) for
second stage inflation of the front-passenger
front air bag. In the second stage, the front
air bags are inflated with the maximum
amount of propellant gas available.
The front air bags are not deployed in
situations where a low impact severity is
predicted. You will then be protected by the
fastened seat belt.
The front-passenger front air bag will only
deploy if:
R the system, based on the OCS weight
sensor readings, detects that the front-
passenger seat is occupied.
R the 45 indicator lamp in the center
console is not lit, ( Y page 42).
R the air bag control unit predicts a high
impact severity.Driver's knee bag
Driver's knee bag : provides additional
protection for the driver against:
R knee injuries
R thigh injuries
R lower leg injuries
Driver's knee bag : deploys below the
steering wheel. During a frontal impact, if the
system determines that air bag deployment
can offer additional protection to that
provided by the seat belt, driver's knee
bag : is deployed along with the driver's air
bag. The driver's knee bag : operates best
in conjunction with a properly positioned and
fastened seat belt.
Side impact air bags
GWARNING
The pressure sensors for side impact air bag
control are located in the doors. Do not
modify any components of the doors or door
trim panels including, for example, the
addition of door speakers.
Improper repair work on the doors or the
modification or addition of components to the
doors create a risk of rendering the side
impact air bags inoperative or causing
unintended air bag deployment. Work on the
doors must therefore only be performed by
qualified technicians. Contact an authorized
Mercedes-Benz Center.
40Occupant safetySafety

GWARNING
If the BAS malfunctions, the brake system still
functions, but without the additional brake
boost available that the BAS would normally
provide in an emergency braking maneuver.
Therefore, the braking distance may increase.
BAS PLUS (Brake Assist System Plus)
BAS PLUS is only available in vehicles
equipped with DISTRONIC PLUS.
i Observe the "Important safety notes"
section ( Y page 59).
At speeds above approximately
20 mph (30 km/h), BAS PLUS assists you
when braking in hazardous situations and
uses the radar sensor system to evaluate the
traffic conditions.
i This device has been approved by the FCC
as a "Vehicular Radar System". The radar
sensor is intended for use in an automotive
radar system only. Removal, tampering, or
altering of the device will void any
warranties, and is not permitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
With the help of the radar sensor system, BAS
PLUS can detect obstacles that are in the
path of your vehicle for an extended period of
time.
At speeds up to approximately
40 mph (70 km/h), BAS PLUS can also detect
stationary obstacles, for example stopped or
parked vehicles.
Should you approach an obstacle and BAS
PLUS has detected a risk of collision, BAS
PLUS calculates the braking force necessary
to avoid a rear-end collision. Should you apply
the brakes forcefully, BAS PLUS can
automatically increase the braking force to a
level suitable for the traffic conditions.
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal.
R there is no longer any danger of a rear-end
collision.
R no obstacle is detected in front of your
vehicle.
BAS PLUS is then deactivated.
For BAS PLUS to assist you when driving, the
radar sensor system must be switched on and
operational, see "Radar sensor system" in the
index.
GWARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations. BAS
PLUS cannot intervene in these cases.
There is a risk of an accident. Always pay
careful attention to the traffic situation and be
ready to brake.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R the possibility of strong radar reflections,
for example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
GWARNING
BAS PLUS does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R in curves
As a result, BAS PLUS cannot intervene in
critical situations. There is a risk of an
60Driving safety systemsSafety

accident. Always pay careful attention to the
traffic situation and be ready to brake.
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensors checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle.
If BAS PLUS is not available due to a
malfunction in the radar sensor system, the
brake system remains available with full
brake boosting effect and BAS.
ESP ®
(Electronic Stability Program)
Important safety notes
i See the "Important safety notes" section
( Y page 59).
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilize the
vehicle. If necessary, the engine output is also
modified to keep the vehicle on the desired
course within physical limits. ESP ®
assists
the driver when pulling away on wet or
slippery roads. ESP ®
can also stabilize the
vehicle during braking.
If ESP ®
intervenes, the ÷ ESP®
warning
lamp flashes in the instrument cluster.
GWARNING
Under no circumstances should you
deactivate ESP ®
when the ÷ ESP®
warning lamp in the instrument cluster
flashes. Proceed as follows:
R when driving off, apply as little throttle as
possible.
R while driving, ease up on the accelerator
pedal.
R adapt your speed to suit the prevailing road
and weather conditions.
Failure to observe these guidelines could
cause the vehicle to skid. ESP ®
cannot
prevent accidents resulting from excessive
speed.
! Vehicles without 4MATIC: switch the
ignition off when:
R the parking brake is being tested using a
dynamometer
R the vehicle is being towed with the front
axle raised
Application of the brakes by ESP ®
may
otherwise destroy the brake system.
! Vehicles with 4MATIC: switch off the
ignition when the parking brake is being
tested on a brake dynamometer.
Application of the brakes by ESP ®
may
otherwise destroy the brake system.
! Vehicles with 4MATIC: function or
performance tests may only be carried out
on a 2-axle dynamometer. If you wish to
operate the vehicle on such a
dynamometer, please consult an
authorized Mercedes-Benz Center in
advance. You could otherwise damage the
drive train or the brake system.
i Only use wheels with the recommended
tire sizes. Only then will ESP ®
function
properly.
ETS/4ETS (Electronic Traction System)GWARNING
Observe "Important safety notes"
( Y page 58).
Traction control is part of ESP ®
.
Traction control brakes the drive wheels
individually if they spin. This enables you to
pull away and accelerate on slippery surfaces,
for example if the road surface is slippery on
one side. On vehicles with 4MATIC, more
drive torque is also transferred to the wheel
or wheels with traction.
Traction control remains active if you
deactivate ESP ®
.
Driving safety systems61SafetyZ

brake, take evasive action or accelerate
significantly, the vehicle may perform
automatic emergency braking. Automatic
emergency braking is not performed until
immediately prior to an accident that can no
longer be avoided.GWARNING
Even if PRE-SAFE ®
Brake slows the vehicle
before an imminent rear-end collision, the
system cannot avert a collision without the
intervention of the driver. There is a risk of an
accident. Brake according to the situation or
take evasive action. Delayed intervention by
the driver can lead to an accident.
GWARNING
PRE-SAFE ®
Brake cannot always detect
complex traffic situations properly.
In these cases, PRE-SAFE(R) Brake may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
There is a risk of an accident. Always pay
particular attention to the traffic situation and
be ready to brake, especially if PRE-SAFE(R)
Brake warns you. Terminate the intervention
in a non-critical driving situation.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R the possibility of strong radar reflections,
for example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
GWARNING
PRE-SAFE ®
Brake does not react:
R to people or animals
R to oncoming vehicles
R
to crossing traffic
R in curves
As a result, PRE-SAFE ®
Brake cannot
intervene in critical situations. There is a risk
of an accident. Always pay careful attention
to the traffic situation and be ready to brake.
In order to maintain the appropriate distance
to the vehicle in front and thus prevent a
collision, you must apply the brakes yourself.XTo activate/deactivate: activate or
deactivate PRE-SAFE ®
Brake in the on-
board computer ( Y page 205).
The Ä symbol appears in the
multifunction display as long as the HOLD
function is not activated ( Y page 172).
On vehicles with Parking Guidance, the
Ä symbol is displayed when
transmission position P is selected or if you
drive faster than 22 mph (35 km/h).
For PRE-SAFE ®
Brake to assist you when
driving, the radar sensor system must be
switched on ( Y page 208) and operational.
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensors checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle.
Theft deterrent locking systems
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. The
engine can be started by anyone with a valid
SmartKey that is left inside the vehicle.
XTo activate with the SmartKey: remove
the SmartKey from the ignition lock.XTo activate with KEYLESS-GO: switch the
ignition off and open the driver's door.XTo deactivate: switch on the ignition.66Theft deterrent locking systemsSafety

The multifunction display shows the RACE
START active message.
RACE START is deactivated when a speed of
approximately 30 mph (Canada: 50 km/h) is
reached. Drive program S+ is activated.
SPORT handling mode remains activated.
RACE START is deactivated immediately if
you release the accelerator pedal during
RACE START or if any of the activation
conditions are no longer fulfilled. The
multifunction display shows the RACE START
not possible See Operator's Manual
message.
i If RACE START is used repeatedly within
a short period of time, it is only available
again after the vehicle has been driven a
certain distance.
4MATIC (permanent four-wheel drive)
4MATIC ensures that all four wheels are
permanently driven. Together with ESP ®
, it
improves the traction of your vehicle
whenever a drive wheel spins due to
insufficient grip.
GWARNING
If a drive wheel is spinning due to insufficient
traction:
R While driving off, apply as little throttle as
possible.
R While driving, ease up on the accelerator
pedal.
R Adapt your speed and driving style to the
prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The 4MATIC cannot prevent accidents
resulting from excessive speed.
! Never tow the vehicle with one axle
raised. This may damage the transfer case.
Damage of this sort is not covered by the
Mercedes-Benz Limited Warranty. All
wheels must remain either on the ground
or be fully raised. Observe the instructions
for towing the vehicle with all wheels in full
contact with the ground.
i In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if
you use winter tires ( M+S tires), with snow
chains if necessary.
PARKTRONIC
Important safety notes
i PARKTRONIC is only available in Canada.
GWARNING
The PARKTRONIC is a supplemental system.
It is not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always remains with the driver.
GWARNING
Make sure no persons or animals are in or
near the area in which you are parking/
maneuvering. Otherwise, they could be
injured.
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is activated automatically when
you:
R switch on the ignition
R shift the transmission to position D, R or N
R release the parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper.
Driving systems175Driving and parkingZ

:Sensors in the front bumper, left-hand
side (example)
Range of the sensors
General notes
The sensors must be free of dirt, ice and
slush; otherwise they may not function
correctly. Clean the sensors regularly, taking
care not to scratch or damage them
( Y page 287).
Side view
Top view
Front sensorsCenterApproximately 40 in
(approximately 100 cm)CornersApproximately 24 in
(approximately 60 cm)
Rear sensors
CenterApproximately 48 in
(approximately 120 cm)CornersApproximately 32 in
(approximately 80 cm)
! When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars.
PARKTRONIC does not detect such objects
when they are in the immediate vicinity of
the vehicle. You could damage the vehicle
or the objects.
The sensors may not detect snow and other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic
car wash, the compressed-air brakes on a
truck or a pneumatic drill could cause
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
Minimum distance
CenterApproximately 8 in
(approximately 20 cm)CornersApproximately 6 in
(approximately 15 cm)
If there is an obstacle within this range, the
relevant warning displays light up and a
warning tone sounds. If the distance falls
below the minimum, the distance may no
longer be shown.
176Driving systemsDriving and parking