ECU MERCEDES-BENZ R-Class 2012 W251 Owner's Manual

Symbols
Registered trademarks:
R BabySmart™ is a registered trademark of
the Siemens Automotive Corp.
R Bluetooth ®
is a registered trademark of the
Bluetooth SIG Inc.
R DTS is a registered trademark of DTS, Inc.
R Dolby and MLP are registered trademarks
of Dolby Laboratories.
R ESP ®
and PRE-SAFE ®
are registered
trademarks of Daimler AG.
R HomeLink ®
is a registered trademark of
Prince, a Johnson Controls Company.
R iPod ®
and iTunes ®
are registered
trademarks of Apple Inc., registered in the
USA and in other countries.
R Logic 7 ®
is a registered trademark of
Harman International Industries,
Incorporated.
R Microsoft ®
is a registered trademark of the
Microsoft Corporation in the USA and in
other countries.
R SIRIUS and associated brands are
registered trademarks of SIRIUS XM Radio
Inc.
R HD Radio and associated brands are
registered trademarks of the iBiquity
Digital Corporation.
R Windows Media ®
is a registered trademark
of the Microsoft Corporation in the USA and
in other countries.
R Gracenote ®
is a registered trademark of
Gracenote, Inc.
R ZagatSurvey ®
and associated brands are
registered trademarks of Zagat.
In this Operator's Manual, you will find the
following symbols:GWARNING
Warning notes draw your attention to hazards
that endanger your health or life, or the health
or life of others.
! These warning notes draw your attention
to hazards that could cause damage to your
vehicle.
i This symbol indicates useful instructions
or further information that could be helpful
to you.XThis symbol designates an
instruction you must follow.XSeveral consecutive symbols
indicate an instruction with several
steps.Y PageThis symbol tells you where you
can find further information on a
topic.YYThis symbol indicates a warning or
an instruction that is continued on
the next page.DisplayThis font indicates a display
message in the multifunction
display/COMAND display.
Parts of the software in the vehicle are
subject to copyright according to ©
2005
The FreeType Project
http://www.freetype.org. All rights
reserved.

SeatFolding down the 2nd row of
seats .............................................. 254
Important safety notes ....................97
Resetting the 2nd row of seats ......256
Resetting the 3rd row of seats ....... 256
Seat belts
Adjusting the driver's and front-
passenger seat belt .........................54
Adjusting the height ......................... 54
Belt force limiters ............................ 55
Cleaning ......................................... 293
Correct usage .................................. 52
Emergency Tensioning Devices ........ 55
Fastening ......................................... 53
Important safety guidelines .............51
Releasing ......................................... 54
Safety guidelines ............................. 39
Special seat belt retractor ...............58
Switching belt adjustment on/off
(on-board computer) ......................209
Warning lamp ................................. 238
Warning lamp (function) ................... 54
Seats
Adjusting (electrically) .....................98
Adjusting (second and third rows) . 101
Adjusting the 4-way lumbar
support .......................................... 105
Adjusting the head restraint ............99
Cleaning the cover .........................293
Correct driver's seat position ........... 96
Folding down the 3rd row of seats . 255
Folding the rear bench seat
forwards/back ............................... 253
Multicontour seat .......................... 105
Seat heating problem ....................106
Seat ventilation problem ................107
Storing settings (memory
function) ........................................ 112
Switching seat heating on/off .......106
Switching the seat ventilation on/
off .................................................. 106
Securing hooks .................................. 258
Sensors (cleaning instructions) ....... 291
Service see ASSYST PLUS service interval
display Service interval display
Displaying service messages .........287
Hiding service messages ...............287
Notes ............................................. 287
Service messages ..........................287
Service products
Brake fluid ..................................... 359
Capacities ...................................... 355
Coolant (engine) ............................ 359
DEF special additives .....................357
Engine oil ....................................... 358
Fuel ................................................ 356
Important safety notes ..................354
Refrigerant (air-conditioning
system) .......................................... 359
Washer fluid ................................... 360
Settings
Factory (on-board computer) .........205
On-board computer .......................205
Setting the air distribution ............... 138
Setting the airflow ............................ 138
Side impact air bag ............................. 42
Side marker lamp (display
message) ............................................ 224
Side marker lamps (changing
bulbs) ................................................. 123
Side windows Convenience closing feature ............88
Convenience opening feature ..........87
Hinged side windows .......................87
Important safety information ...........86
Opening/closing .............................. 86
Problem (malfunction) .....................89
Resetting ......................................... 89
Sliding sunroof
Important safety notes ....................89
Opening/closing .............................. 90
Problem (malfunction) .....................92
Resetting ......................................... 90
see Panorama roof with power
tilt/sliding panel
SmartKey
Changing the battery .......................76
Changing the programming .............75
Checking the battery .......................76
Convenience closing feature ............88
Convenience opening feature ..........87
Display message ............................ 236Index15

Administration (NHTSA) in addition to
notifying Mercedes-Benz USA, LLC.
If NHTSA receives similar complaints, it may
open an investigation, and if it finds that a
safety defect exists in a group of vehicles, it
may order a recall and remedy campaign.
However, NHTSA cannot become involved in
individual problems between you, your
dealer, or Mercedes-Benz USA, LLC.
To contact NHTSA, you may call the Vehicle
Safety Hotline toll-free at
1-888-327-4236 (TTY: 1-800-424-9153); go
to: http://www.safercar.gov ; or write to:
Administrator, NHTSA Headquarters,
1200 New Jersey Avenue, SE, West Building,
Washington, DC 20590.
You can also obtain additional information
about vehicle safety from:
http://www.safercar.gov .
Limited Warranty
! Follow the instructions in this manual
about the proper operation of your vehicle
as well as about possible vehicle damage.
Damage to your vehicle that arises from
culpable contraventions against these
instructions are not covered either by
Mercedes-Benz Limited Warranty or by the
New or Used-Vehicle Warranty of
Daimler AG.
Data stored in the vehicle
Information about electronic data
acquisition in the vehicle
( Including notice pursuant to California Code
§ 9951)
Your vehicle records electronic data. If your
vehicle is equipped with mbrace 3
, data is
transmitted in the event of an accident.
This information helps, for example, to test
vehicle systems after an accident and to
continually improve vehicle safety.
Daimler AG can access this data and submit
it:
R for safety research or vehicle diagnosis
purposes
R with the consent of the vehicle owner
R on the instruction of prosecuting
authorities
R for use in arbitration of disputes that
involve Daimler AG, its affiliates or its sales
and service organizations
R as otherwise required or permitted by law.
Please observe the mbrace 3
purchase
agreement for further details on the recording
and transfer of data by this system.3 The system is called TELE AID in Canada.Introduction25Z

being up to or less than the weight of a typical
12-month-old child in a standard child
restraint, the 42 indicator lamp
will illuminate when the engine is started and
remain illuminated. This indicates that the
front passenger front air bag is deactivated.
When the OCS senses that the front
passenger seat is classified as being empty,
the 42 indicator lamp will
illuminate when the engine is started and
remain illuminated. This indicates that the
front passenger front air bag is deactivated.
When the OCS senses that the front
passenger seat occupant is classified as
being heavier than the weight of a typical 12-
month-old child seated in a standard child
restraint or as being a small individual (such
as a young teenager or a small adult), the
42 indicator lamp will illuminate
for approximately 6 seconds when the engine
is started. Depending on occupant weight
sensor readings from the seat, it will then
remain illuminated or go out. With the
42 indicator lamp illuminated,
the front passenger front air bag is
deactivated. With the 42
indicator lamp out, the front passenger front
air bag is activated.
When the OCS senses that the front
passenger seat occupant is classified as an
adult or someone larger than a small
individual, the 42 indicator lamp
will illuminate for approximately six seconds
when the engine is started and then go out.
This indicates that the front passenger front
air bag is activated.
If the 42 indicator lamp is
illuminated, the front passenger front air bag
is deactivated and will not be deployed.If the 24 indicator lamp is not
illuminated, the front passenger front air bag
is activated and will be deployed
R in the event of certain frontal impacts
R if the impact exceeds a predetermined
triggering threshold
R independently of the side impact air bags
If the front passenger front air bag is
deployed, the rate of inflation will be
influenced by
R the rate of vehicle deceleration as assessed
by the air bag control unit
R the front passenger's weight category as
identified by the OCS
For further information, see "air bag display
messages" ( Y page 220).GWARNING
According to accident statistics, children are
safer when properly restrained on the rear
seats than on the front-passenger seat. Thus,
we strongly recommend that children be
placed in the rear seats whenever possible.
Regardless of seating position, children 12
years old and under must be seated and
properly secured in an appropriately sized
child restraint system or booster seat
recommended for the size and weight of the
child.
The infant or child restraint system must be
properly secured with the vehicle's seat belt,
the seat belt and Top Tether strap, or lower
anchors and Top Tether strap, fully in
accordance with the child seat
manufacturer's instructions.
Occupants, especially children, should always
sit as upright as possible, wear the seat belt
properly and use an appropriate sized infant
restraint, toddler restraint, or booster seat
recommended for the size and weight of the
child.
Occupant safety45SafetyZ

Children can be killed or seriously injured by
an inflating air bag. Note the following
important information when circumstances
require you to place a child in the front-
passenger seat:
R Your vehicle is equipped with air bag
technology designed to deactivate the
front-passenger front air bag in your vehicle
when the system senses the weight of a
typical 12-month-old child or less along
with the weight of a standard appropriate
child restraint on the front-passenger seat.
R A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates in a collision which
could occur under some circumstances,
even with the air bag technology installed
in your vehicle. The only means to eliminate
this risk completely is never to place a child
in a rear-facing child restraint in the front-
passenger seat. We therefore strongly
recommend that you always place a child
in a rear-facing child restraint on the rear
seat.
R If you install a rear-facing child restraint on
the front-passenger seat, make sure the
42 indicator lamp is
illuminated, indicating that the front-
passenger front air bag is deactivated.
Should the 42 indicator lamp
not illuminate or go out while the restraint
is installed, please check installation.
Periodically check the 42
indicator lamp while driving to make sure
the 42 indicator lamp is
illuminated. If the 42 indicator
lamp goes out or remains out, do not
transport a child on the front-passenger
seat until the system has been repaired.
A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates.R If you place a child in a forward-facing child
restraint on the front-passenger seat:
- move the seat as far back as possible
- use the proper child restraint
recommended for the age, size and
weight of the child
- secure child restraint with the vehicle's
seat belt according to the child seat
manufacturer's instructions
R For children larger than a typical 12-month-
old child, the front-passenger front air bag
can be activated or deactivated.
If the driver's air bag deploys, this does not
mean that the front-passenger front air bag
also has to deploy.
The OCS may have detected that the seat:
R was empty or occupied by a person with a
weight of up to or less than that of a typical
12-month-old child seated in a standard
child restraint
R was occupied by a small individual, such as
a young teenager or a small adult
R was occupied by a child in a child restraint
system, whose weight is greater than that
of a typical 12-month-old child.
These are examples of when the OCS
deactivates the front-passenger front air bag.
Deactivation takes place although the
collision fulfills the criteria for deploying the
driver's air bag.
If the SmartKey has been removed from the
ignition lock or is in position 0, indicator lamp
42 : does not light up.
46Occupant safetySafety

keep both feet on the floor in front of the
seat.
R When using a seat belt to secure infant
restraints, toddler restraints, or children in
booster seats, always follow the child seat
manufacturer's instructions.GWARNING
Do not pass seat belts over sharp edges. They
could tear.
Do not allow the seat belt to get caught in the
door or in the seat adjustment mechanism.
This could damage the seat belt.
Never attempt to make modifications to seat
belts. This could impair the effectiveness of
the seat belts.
Fastening seat belts
GWARNING
According to accident statistics, children are
safer when properly restrained on the rear
seats than on the front-passenger seat. Thus,
we strongly recommend that children be
placed in the rear seat whenever possible.
Regardless of seating position, children 12
years old and under must be seated and
properly secured in an appropriately sized
child restraint system or booster seat
recommended for the size and weight of the
child. For additional information, see the
"Children in the vehicle" section.
A child's risk of serious or fatal injuries is
significantly increased if the child restraints
are not properly secured in the vehicle and/
or the child is not properly secured in the child
restraint.
XAdjust the seat and move the backrest to
an almost vertical position ( Y page 96).XPull the seat belt smoothly through belt
sash guide :.XWithout twisting it, guide the shoulder
section of the seat belt across the middle
of your shoulder and the lap section across
your hips.XEngage belt tongue ; in buckle =.
Seat-belt adjustment: if necessary, the
driver's and front-passenger seat belts
automatically adjust to the upper body
( Y page 54).XIf necessary, adjust the seat belt to the
appropriate height ( Y page 54).XIf necessary, pull upwards on the shoulder
section of the seat belt to tighten the belt
across your body.
All seat belts except the driver's seat belt are
equipped with a special seat belt retractor to
securely fasten child restraint systems in the
vehicle. For further information on special
seat belt retractors, see ( Y page 58).
Occupant safety53SafetyZ

direction during the initial stages of the
impact
R if, in the event of a side impact, the vehicle
is subjected to high lateral acceleration/
deceleration
R if in certain situations where the vehicle
overturns and the system determines that
it can provide additional protection
If the air bags are deployed, you will hear a
bang, and a small amount of powder may also
be released. Only in rare cases will the bang
affect your hearing. The powder that is
released generally does not constitute a
health hazard. The + SRS warning lamp
lights up.GWARNING
Pyrotechnic Emergency Tensioning Devices
that have been deployed must be renewed.
For your safety, when disposing of Emergency
Tensioning Devices, always observe the
safety instructions. These are available from
any authorized Mercedes-Benz Center.
The PRE-SAFE ®
system has electrically
operated reversible pre-tensioners that do
not require replacement after activation.
! If the front-passenger seat is not
occupied, do not engage the seat belt
tongue in the buckle on the front-
passenger seat. Otherwise, the Emergency
Tensioning Device could be triggered in the
event of an accident.
Children in the vehicle
Child restraint systems
Important safety notes
We recommend that all infants and children
be properly secured in an infant or child
restraint system at all times while the vehicle
is in motion.
The use of seat belts and infant and child
restraint systems is required by law in all 50
states, the District of Columbia, the U.S.
territories and all Canadian provinces.
Infants and children must always be seated in
an appropriate infant or child restraint system
recommended for the size and weight of the
child. The infant or child restraint system
must be properly secured in accordance with
the manufacturer's instructions. All infant or
child restraint systems must meet U.S.
Federal Motor Vehicle Safety Standards 213
and 225 and Canadian Motor Vehicle Safety
Standards 213 and 210.2.
An information label on the child restraint
system indicates whether it meets these
standards. This information is also provided
in the installation instructions supplied with
the child restraint system.
Always read and follow the manufacturer's
instructions when using an infant or child
restraint system or booster seat.
Observe all warning signs in the vehicle
interior and on the infant or child restraint.GWARNING
According to accident statistics, children are
safer when properly restrained on the rear
seats than on the front-passenger seat. Thus,
we strongly recommend that children be
placed in the rear seats whenever possible.
Regardless of seating position, children 12
years old and under must be seated and
properly secured in an appropriately sized
child restraint system or booster seat
recommended for the size and weight of the
child.
The infant or child restraint system must be
properly secured with the vehicle's seat belt,
the seat belt and Top Tether strap, or lower
anchors and Top Tether strap, fully in
accordance with the child seat
manufacturer's instructions.
Occupants, especially children, should always
sit as upright as possible, wear the seat belt
properly and use an appropriate sized infant
restraint, toddler restraint, or booster seat
recommended for the size and weight of the
child.
56Children in the vehicleSafety

Children can be killed or seriously injured by
an inflating air bag. Note the following
important information when circumstances
require you to place a child in the front-
passenger seat:
R Your vehicle is equipped with air bag
technology designed to deactivate the
front-passenger front air bag in your vehicle
when the system senses the weight of a
typical 12-month-old child or less along
with the weight of a standard appropriate
child restraint on the front-passenger seat.
R A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates in a collision which
could occur under some circumstances,
even with the air bag technology installed
in your vehicle. The only means to eliminate
this risk completely is never to place a child
in a rear-facing child restraint in the front-
passenger seat. We therefore strongly
recommend that you always place a child
in a rear-facing child restraint on the rear
seat.
R If you install a rear-facing child restraint on
the front-passenger seat, make sure the
42 indicator lamp is
illuminated, indicating that the front-
passenger front air bag is deactivated.
Should the 42 indicator lamp
not illuminate or go out while the restraint
is installed, please check installation.
Periodically check the 42
indicator lamp while driving to make sure
the 42 indicator lamp is
illuminated. If the 42 indicator
lamp goes out or remains out, do not
transport a child on the front-passenger
seat until the system has been repaired.
A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates.R If you place a child in a forward-facing child
restraint on the front-passenger seat:
- move the seat as far back as possible
- use the proper child restraint
recommended for the age, size and
weight of the child
- secure child restraint with the vehicle's
seat belt according to the child seat
manufacturer's instructions
R For children larger than a typical 12-month-
old child, the front-passenger front air bag
can be activated or deactivated.GWARNING
Infants and small children should never share
a seat belt with another occupant. During an
accident, they could be crushed between the
occupant and seat belt.
A child's risk of serious or fatal injuries is
significantly increased if the child restraints
are not properly secured in the vehicle and/
or the child is not properly secured in the child
restraint.
Children too big for a toddler restraint must
ride in seats using regular seat belts. Position
the shoulder belt across the chest and
shoulder, not face or neck. A booster seat
may be necessary to achieve proper seat belt
positioning for children over 41 lb (18 kg) until
they reach a height where a lap/shoulder belt
fits properly without a booster.
When the child restraint is not in use, remove
it from the vehicle or secure it with the seat
belt to prevent the child restraint from
becoming a projectile in the event of an
accident.
If an infant or child is traveling in the vehicle:
XSecure the infant or child with an
appropriate infant or child restraint
recommended for the child's age and
weight.XMake sure that the infant or child is
properly secured at all times while the
vehicle is in motion.Children in the vehicle57SafetyZ

GWARNING
When leaving the vehicle, always remove the
SmartKey from the ignition lock. Always take
the SmartKey with you and lock the vehicle.
Do not leave children unattended in the
vehicle, even if they are secured in a child
restraint system, or with access to an
unlocked vehicle. A child's unsupervised
access to a vehicle could result in an accident
and/or serious personal injury. The children
could:
R injure themselves on parts of the vehicle
R be seriously or fatally injured through
excessive exposure to extreme heat or cold
R injure themselves or cause an accident with
vehicle equipment that can be operated
even if the SmartKey is removed from the
ignition lock or removed from the vehicle,
such as seat adjustment, steering wheel
adjustment, or the memory function
If children open a door, they could injure other
persons or get out of the vehicle and injure
themselves or be injured by following traffic.
Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and the child could be burned on these
parts.
GWARNING
Do not carry heavy or hard objects in the
passenger compartment or trunk unless they
are firmly secured in place.
Unsecured or improperly positioned cargo
increases a child's risk of injury in the event
of
R strong braking maneuvers
R sudden changes of direction
R an accident
Special seat belt retractor
All seat belts except the driver's seat belt are
equipped with a special seat belt retractor.
When activated, the special seat belt
retractor ensures the seat belt will not
slacken once the child restraint system has
been secured.
Installing a child restraint system:XAlways comply with the manufacturer's
installation instructions.XPull the seat belt smoothly from the inertia
reel.XEngage the seat belt tongue in the belt
buckle.
Activating the special seat belt retractor:
XPull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should
hear a ratcheting sound. The special seat
belt retractor is enabled.XPush down on the child restraint system to
take up any slack.
Removing a child restraint system/
deactivating the special seat belt retractor:
XAlways comply with the manufacturer's
installation instructions.XPress the seat belt release button and
guide the belt tongue to the belt outlet.
The special seat belt retractor is
deactivated.GWARNING
Never release the seat belt buckle while the
vehicle is in motion, since the special seat belt
retractor will be deactivated.
LATCH-type (ISOFIX) child seat anchors
in the rear
GWARNING
Children that are too large for a child restraint
must travel in seats using normal seat belts.
Position shoulder belt across the chest and
shoulder, not face or neck.
In order to attain the correct seating position
for children weighing over 41 lb (18 kg), it may
be necessary to use a booster seat until they
reach a height where a normal lap/shoulder
58Children in the vehicleSafety

seat belt lies properly across their bodies
without the need for a booster seat.
Install the child restraint system according to
the manufacturer's instructions.
The child restraint system must be installed
firmly on both brackets.
An incorrectly installed child restraint system
can come loose in the event of an accident,
causing the child to be severely or fatally
injured.
Child restraint systems/child restraint
retaining brackets that are damaged or have
suffered damage due to an impact must be
replaced.
LATCH-type (ISOFIX) is a standardized
securing system for specially designed child
restraint systems on the rear seats.
Securing rings for two LATCH-type (ISOFIX)
child restraint systems are installed on the
left and right:
R on the seat cushions of the outer seats in
the second row
R on the backrests of the seats in the third
row of seats
Secure non LATCH-type (ISOFIX) child
restraint systems using the vehicle's seat belt
system. Always install child restraint systems
according to the manufacturer's instructions.XMove the rear seat backrests in the second
row to an upright position ( Y page 101).
The securing rings on the outer seats in the
second row of seats are covered by an
upholstered lining.
:Securing rings for outer seats in the
second row;Installation instructions for the securing
ringXSlide the upholstered lining to the side.XInstall the LATCH-type (ISOFIX) child
restraint system. Comply with the
manufacturer's instructions when doing
so.
The securing rings on the seats in the third
row are covered by protective caps.
XRemove protective caps = in the third row
of seats.Children in the vehicle59SafetyZ