tail MERCEDES-BENZ S-Class 2012 W221 Service Manual

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 31).
Important safety notes
You will find an illustration of the instrument
cluster in the "At a glance" section
( Y page 35).
GWARNING
A driver's attention to the road and traffic
conditions must always be his/her primary
focus when driving.
For your safety and the safety of others,
selecting features through the multifunction
steering wheel should only be done by the
driver when traffic and road conditions permit
it to be done safely.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h ), your vehicle is
covering a distance of 44 feet (approximately
14 m) every second.
GWARNING
No messages will be displayed if either the
instrument cluster or the multifunction
display is inoperative.
As a result, you will not be able to see
information about your driving conditions,
such as
R speed
R outside temperature
R warning/indicator lamps
Rmalfunction/warning messages
R failure of any systems
Driving characteristics may be impaired.
If you must continue to drive, do so with added
caution. Contact an authorized Mercedes-
Benz Center as soon as possible.GWARNING
HYBRID vehicles: It is imperative that you read
the HYBRID Supplemental Operating
Instructions included in your vehicle literature
portfolio. You may otherwise not receive all
necessary safety information and warning for
the operation of your vehicle.
GWARNING
Malfunction and warning messages are only
indicated for certain systems and are
intentionally not very detailed. The
malfunction and warning messages are
simply a reminder with respect to the
operation of certain systems. They do not
replace the owner's and/or driver's
responsibility to maintain the vehicle's
operating safety. Have all required
maintenance and safety checks performed on
the vehicle. Bring the vehicle to an authorized
Mercedes-Benz Center to address the
malfunction and warning messages.
Displays and operation
Coolant temperature display
GWARNING
Driving when your engine is overheated can
cause some fluids which may have leaked into
the engine compartment to catch fire. You
could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of the
372Displays and operationOn-board computer and displays

XPress a.
The current selection is displayed.XTo activate/deactivate: press a
again.
When ATTENTION ASSIST ( Y page 356) is
activated, the À symbol appears in the
multifunction display when the ignition is on.
Activating/deactivating Blind Spot
Assist
You can use the Blind Spot Assist
function to activate or deactivate Blind Spot
Assist ( Y page 360) or Active Blind Spot
Assist ( Y page 364).
XPress = or ; on the steering wheel
to select the DriveAssist menu.XPress 9 or : to select Blind Spot
Assist .XPress a.
The current selection is displayed.XTo activate/deactivate: press a
again.
Activating/deactivating Lane Keeping
Assist
You can use the Lane Keeping Assist
function to activate/deactivate Lane Keeping
Assist ( Y page 362) or Active Lane Keeping
Assist ( Y page 367).
XPress the = or ; button on the
steering wheel to select the DriveAssist
menu.XPress the 9 or : button to select
Lane Keeping Assist .XPress a.
The current selection is displayed.XTo activate/deactivate: press a
again.
If Lane Keeping Assist or Active Lane keeping
Assist is activated, the multifunction display
shows the à symbol when the ignition is
switched on.
Service menu
In the Service menu you can:
R call up display messages ( Y page 388)
R check the tire pressure electronically
( Y page 497)
R call up the service due date ( Y page 462)
R check the oil level ( Y page 457)
Settings menu
Introduction
The Settings menu can be used for:
R switching the daytime running lamps on/
off
R switching Adaptive Highbeam Assist on/
off
R showing or hiding the additional
speedometer
R selecting the units for speed and distance
R switching the belt adjustment on/off
R activating/deactivating the radar sensor
system
Switching the daytime running lamps
on/off
This function is not available in Canada.
If you have activated the Daytime Running
Light function and the light switch is in the
$ or c position, the daytime running
lamps are switched on automatically when
the engine is running.
In the dark, the following also light up:
R the parking lamps
R the tail lamps
R the license plate lamp
R the side marker lamps
If you turn the light switch to a different
position, the corresponding lights are
switched on. If you switch off the daytime
running lamps at night, make sure that the
light switch is set to L or c .
The factory setting is On.
Menus and submenus385On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutionsb
Check Center Brake
LampThe high-mounted brake lamp is faulty.XCheck whether you are permitted to change the bulb yourself
( Y page 282).
or
XVisit a qualified specialist workshop.b
Check Left Tail
and Brake
Lamp or Check Right
Tail and Brake LampThe left or right-hand tail lamp/brake lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 282).
or
XVisit a qualified specialist workshop.b
Check Left High
Beam or Check Right
High BeamThe left or right-hand high beam is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 282).
or
XVisit a qualified specialist workshop.b
Check Left License
Plate Lamp or Check
Right License
Plate LampThe left or right-hand license plate lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 282).
or
XVisit a qualified specialist workshop.b
Check Left Fog
Lamp or Check Right
Fog LampThe left-hand or right-hand front fog lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 282).
or
XVisit a qualified specialist workshop.b
Check Rear Left
Fog Lamp or Check
Rear Right Fog LampThe left-hand or right-hand rear fog lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 282).
or
XVisit a qualified specialist workshop.b
Check Front Left
Parking
Lamp or Check Front
Right Parking LampThe front left or front right parking or standing lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 282).
or
XVisit a qualified specialist workshop.402Display messagesOn-board computer and displays

XPress and hold Roadside Assistance
button : for more than two seconds.
This initiates a call to the Mercedes-Benz
Customer Assistance Center. The indicator
lamp in Roadside Assistance button :
flashes while the call is active. The
Connecting Call message appears in the
multifunction display and the COMAND
display. The audio output is muted.
If a connection can be established, the Call
Connected message appears in the
multifunction display and in the COMAND
display.
If a cellular phone network is available and
there is sufficient GPS reception, the mbrace
system transmits data to the Mercedes-Benz
Customer Assistance Center, for example:
R current location of the vehicle
R vehicle identification number
i The multifunction display and COMAND
display show that an mbrace call is active.
You can change to the navigation menu by
pressing the S button during the call,
for example.
Voice output is not available.
A voice connection is established between
the Mercedes-Benz Customer Assistance
Center and the vehicle occupants.
XDescribe the type of assistance needed.
The Mercedes-Benz Customer Assistance
Center either sends a qualified Mercedes-
Benz technician or organizes for your vehicle
to be transported to the nearest authorized
Mercedes-Benz Center. You may be charged
for services such as repair work and/or
towing. Further details are available in your
mbrace manual.
i The mbrace system failed to initiate a
Roadside Assistance call if:
R the indicator lamp in Roadside
Assistance button : is flashing
continuously.
R no voice connection to the Mercedes-
Benz Customer Assistance Center was
established.
This may be because the corresponding
mobile phone network is not available.
The Call Failed message appears in the
multifunction display.
The COMAND display shows the Call
could not be connected! message.
Press W to confirm the message.XTo end a call: press the ~ button on the
multifunction steering wheel.
or
XPress the corresponding button for ending
a phone call on the COMAND telephone
keypad.
MB Info call button
XOpen the stowage compartment under the
armrest ( Y page 433).XPress and hold MB Info call button : for
more than two seconds.
This initiates a call to the Mercedes-Benz
Customer Assistance Center. The indicator
lamp in MB Info call button : flashes while446FeaturesStowing and features

the connection is being established. The
Connecting Call message appears in the
multifunction display. The COMAND
display shows the Information Call
Activated message. The audio output is
muted.
If a connection can be established, the Call
Connected message appears in the
multifunction display.
The COMAND display shows the
Information Call Activated message.
If a cellular phone network is available and
there is sufficient GPS reception, the mbrace
system transmits data to the Mercedes-Benz
Customer Assistance Center, for example:
R current location of the vehicle
R vehicle identification number
i The COMAND display shows that an
mbrace call is active. You can change to the
navigation menu by pressing the S
button during the call, for example.
Voice output is not available.
A voice connection is established between
the Mercedes-Benz Customer Assistance
Center and the vehicle occupants. You can
obtain information on how to operate your
vehicle's systems, on the location of the
nearest authorized Mercedes-Benz Center,
and on further products and services offered
by Mercedes-Benz USA.
Further details on the mbrace system can be
found under http://www.mbusa.com 25
.
Log in under "Owners Online".
i The mbrace system failed to initiate an
MB Info call if:
R the indicator lamp in MB Info call
button : is flashing continuously.
R no voice connection to the Mercedes-
Benz Customer Assistance Center was
established.
This may be because the corresponding
mobile phone network is not available.
The Call Failed message appears in the
multifunction display.
The COMAND display shows the Call
could not be connected! message.
Press W to confirm the message.XTo end a call: press the ~ button on the
multifunction steering wheel.
or
XPress the corresponding button for ending
a phone call on the COMAND telephone
keypad.
Call priority
When service calls are active, e.g. Roadside
Assistance or MB Info calls, an emergency
call can still be initiated. In this case, an
emergency call will take priority and override
all other active calls.
The indicator lamp of the respective button
flashes until the call is ended. An emergency
call can only be terminated by the Mercedes-
Benz Customer Assistance Center. All other
calls can be ended by pressing the ~
button on the multifunction steering wheel or
the corresponding button for ending a
telephone call on the COMAND telephone
keypad.
Downloading destinations in COMAND
i The components and operating principles
of COMAND can be found on
( Y page 118).
i You can only use the Destination
Download function if the vehicle is
equipped with a navigation system.
Destination Download gives you access to a
database with over 15 million points of
interest (POIs)/important destinations that
can be downloaded onto the navigation
system of your vehicle. If you know the
destination, you can download the address or
obtain the location of points of interest
25 USA only.Features447Stowing and featuresZ

Cleaning the sensorsXClean sensors : of the driving systems
with water, car shampoo and a soft cloth.
! When cleaning the sensors with a power
washer, maintain a distance between the
vehicle and the nozzle of the power washer
of at least 11.8 in (30 cm). Information
about the correct distance is available from
the equipment manufacturer.
Cleaning the rear view camera
XUse clear water and a soft cloth to clean
camera lens :.
!
Do not clean the camera lens and the area
around the rear view camera with a power
washer.
Cleaning the exhaust tail pipes
Impurities combined with the effects of road
grit and corrosive environmental factors may
cause flash rust to form on the surface. You
can restore the original shine of the exhaust
tail pipe by cleaning it regularly, especially in
winter and after washing.
! Do not clean the exhaust tail pipes with
alkaline-based cleaning agents, such as
wheel cleaner.
XClean the exhaust tail pipes with a chrome
care product tested and approved by
Mercedes-Benz.
Interior care
Cleaning the display
XBefore cleaning the display, make sure that
it is switched off and has cooled down.XClean the display surface using a
commercially-available microfiber cloth
and TFT/LCD display cleaner.XDry the display surface using a dry
microfiber cloth.
! For cleaning, do not use any of the
following:
R alcohol-based thinner or gasoline
R abrasive cleaning agents
R commercially-available household
cleaning agents
These may damage the display surface. Do
not put pressure on the display surface
when cleaning. This could lead to
irreparable damage to the display.
Cleaning Night View Assist Plus
! Never clean the camera lens. When
cleaning the field of vision of the driving
systems, make sure that you do not spray
glass cleaner on the camera lens. If the
camera lens is dirty, visit a qualified
specialist workshop.
Care467Maintenance and careZ

Towing and tow-starting
Important safety notes
GWARNING
Hybrid vehicles: be sure to read the "HYBRID"
supplement. Otherwise, you could fail to
recognize dangers.
GWARNING
If you tow the vehicle, you must use a rigid
towing bar if:
R the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the power supply
or the vehicle's electrical system.
The power assistance for the steering and the
brake force booster do not work when the
engine is not running. You will need more
force to steer and brake, you may have to
depress the brake pedal with maximum force.
Before towing away, make sure that the
steering can be moved and is not locked.
If you tow or tow-start another vehicle, its
weight must not exceed the maximum
permissible gross vehicle weight of your
vehicle.
GWARNING
The vehicle is braked when the HOLD function
or DISTRONIC PLUS is activated. Therefore,
deactivate HOLD and DISTRONIC PLUS if the
vehicle is to be towed.
It is better to have the vehicle transported
than to have it towed.
! You may only tow the vehicle a maximum
distance of 30 miles (50 km). A towing
speed of 30 mph (50 km/h) must not be
exceeded.
For towing distances over 30 miles
(50 km), the vehicle must loaded onto a
transporter.
! Make sure that the electric parking brake
is released. If the electric parking brake is
faulty, visit a qualified specialist workshop.
! Only secure the tow rope or tow bar at the
towing eyes. Otherwise, the vehicle could
be damaged.
! Do not use the towing eye for recovery,
as this could damage the vehicle. If in
doubt, recover the vehicle with a crane.
! When towing, pull away slowly and
smoothly. If the tractive power is too high,
the vehicles could be damaged.
! Do not tow with sling-type equipment.
This could damage the vehicle.
! When towing vehicles with KEYLESS-GO,
use the key instead of the Start/Stop
button. Otherwise, the automatic
transmission may shift to position P when
the driver's or front-passenger door are
opened, which could lead to damage to the
transmission.
The automatic transmission must be in
position N when the vehicle is being towed.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the SmartKey to position 2 in
the ignition lock
R cannot shift the automatic transmission to
position N
i Before the vehicle is towed, switch off the
automatic locking feature ( Y page 264).
You could otherwise be locked out when
pushing or towing the vehicle.
Installing/removing the towing eye
Installing the towing eye
XRemove the towing eye from the vehicle
tool kit ( Y page 472).GWARNING
The exhaust tail pipe may be hot. You could
burn yourself if you touch the tail pipe. Be
particularly careful when removing the rear
cover.
Towing and tow-starting483Breakdown assistanceZ

you can also define reference values
manually as described here.
Restart the tire pressure monitor after you
have set the tire pressure to the value
recommended for the desired driving
situation ( Y page 493). Only correct tire
pressures on cold tires. Comply with the
recommended tire pressures on the Tire and
Loading Information placard on the B-pillar on
the driver's side. Additional tire pressure
values for driving at high speeds or with heavy
loads can be found in the tire pressure table
on the inside of the fuel filler flap.XMake sure that the tire pressure is correct
on all four wheels.XMake sure that the SmartKey is in position
2 in the ignition lock.XPress the = or ; button on the
steering wheel to select the Service
menu.XPress the 9 or : button to select
Tire Pressure .XPress the a button.
The multifunction display shows the
current tire pressure of the individual tires
or the Tire Pressures Displayed
After Driving A Few Minutes
message.XPress the : button.
The Use Current Pressures As New
Reference Values message appears in
the multifunction display.
If you wish to confirm the restart:
XPress the a button.
The Tire Pressure Monitor
Restarted message appears in the
multifunction display.
After driving for a few minutes, the system
checks whether the current tire pressures
are within the specified range. The new tire
pressures are then accepted as reference
values and monitored.If you wish to cancel the restart:XPress the % button.
The tire pressure values stored at the last
restart will continue to be monitored.
Loading the vehicle
Instruction labels for tires and loads
GWARNING
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
Two instruction labels on your vehicle show
the maximum possible load.
(1)The Tire and Loading Information placard
on the B-pillar on the driver's side. The
Tire and Loading Information placard
shows the maximum permissible number
of occupants and the maximum
permissible vehicle load. It also contains
details of the tire sizes and
corresponding pressures for tires
mounted at the factory.(2)The vehicle identification plate is on the
B-pillar on the driver's side. The vehicle
identification plate informs you of the
gross vehicle weight rating. It is made up
of the vehicle weight, all vehicle
occupants, the fuel and the cargo. You
can also find information about the
maximum gross axle weight rating on the
front and rear axle.
The maximum gross axle weight rating is
the maximum weight that can be carried
by one axle (front or rear axle). Never
exceed the maximum load or the
maximum gross axle weight rating for the
front or rear axle.500Loading the vehicleWheels and tires

:B-pillar, driver's side
Maximum permissible gross vehicle
weight rating
i The specifications shown on the Tire and
Loading Information placard in the
illustration are examples. The maximum
permissible gross vehicle weight rating is
vehicle-specific and may differ from that in
the illustration. You can find the valid
maximum permissible gross vehicle weight
rating for your vehicle on the Tire and
Loading Information placard.
XThe Tire and Loading Information placard
gives you details on maximum permissible
gross vehicle weight rating :: "The gross
weight of occupants and luggage must
never exceed XXX kilograms or XXX
pounds."
The gross weight of all vehicle occupants,
cargo, luggage and trailer load/noseweight (if
applicable) must not exceed the specified
value.
Number of seats
i The specifications shown on the Tire and
Loading Information placard in the
illustration are examples. The number of
seats is vehicle-specific and can differ from
the details shown. The number of seats in
your vehicle can be found on the Tire and
Loading Information placard.
Maximum number of seats : determines the
maximum number of occupants allowed to
travel in the vehicle. This information can be
found on the Tire and Loading Information
placard.
Determining the correct load limit
Step-by-step instructions
The following steps have been developed as
required of all manufacturers under Title 49,
Code of U.S. Federal Regulations, Part 575
pursuant to the "National Traffic and Motor
Vehicle Safety Act of 1966".
XStep 1: Locate the statement "The
combined weight of occupants and cargo
should never exceed XXX kg or XXX lbs." on
your vehicle’s Tire and Loading Information
placard.XStep 2: Determine the combined weight of
the driver and passengers that will be riding
in your vehicle.XStep 3: Subtract the combined weight of
the driver and passengers from XXX
kilograms or XXX lbs.Loading the vehicle501Wheels and tiresZ

Example 1Example 2Example 3Step 3Permissible cargo
and trailer load/
noseweight
(maximum gross
vehicle weight rating
from the Tire and
Loading Information
placard minus the
gross weight of all
occupants)1500 lbs
(680 kg) -
750 lbs (340 kg)
= 750 lbs
(340 kg)1500 lbs
(680 kg) -
540 lbs (245 kg)
= 960 lbs
(435 kg)1500 lbs
(680 kg) -
150 lbs (68 kg) =
1350 lbs
(612 kg)
The higher the weight of all the occupants, the smaller the maximum load for luggage.
Further information can be found under "Towing a trailer" ( Y page 504).
Vehicle identification plate
Even if you have calculated the total load
carefully, you should still make sure that the
gross vehicle weight rating and the gross axle
weight rating are not exceeded. Details can
be found on the vehicle identification plate on
the B-pillar on the driver's side (Y page 500).
Gross vehicle weight: the gross weight of
the vehicle, all passengers, cargo and trailer
load/noseweight (if applicable) must not
exceed the permissible gross vehicle weight.
Gross axle weight rating: the maximum
permissible load that can be carried by one
axle (front or rear axle).
To ensure that your vehicle does not exceed
the maximum permissible values (gross
vehicle weight and maximum gross axle
weight rating), have your loaded vehicle
(including driver, occupants, cargo, and full
trailer load if applicable) weighed on a
suitable vehicle weighbridge.
Trailer load/noseweight
The trailer load/noseweight affects the gross
weight of the vehicle. If a trailer is attached,
the trailer load/noseweight is included in the
load along with occupants and luggage. The
trailer load/noseweight is usually
approximately 10% of the gross weight of the
trailer and its load.
Your Mercedes-Benz has been designed
primarily to carry passengers and their
luggage. Mercedes-Benz does not
recommend towing a trailer with your vehicle.
Maximum load rating
GWARNING
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
504Maximum load ratingWheels and tires