traction control MERCEDES-BENZ R-Class 2012 W251 Owner's Manual

1, 2, 3 ...
115 V socket ...................................... 268
12 V socket see Sockets
4ETS (Electronic Traction System) .... 66
A
ABS (Anti-lock Braking System) Display message ............................ 214
Function/notes ................................ 65
Important safety notes ....................65
Warning lamp ................................. 240
Activating/deactivating cooling
with air dehumidification ................. 135
Active service system PLUS see ASSYST PLUS service interval
display
Adaptive Damping System (ADS) ..... 181
Additives (engine oil) ........................ 358
Adjusting the armrest (2nd row of
seats) .................................................. 102
ADS (Adaptive Damping System) ..... 181
Air bags Display message ............................ 220
Front air bag (driver, front
passenger) ....................................... 42
Important safety notes ....................40
Safety guidelines ............................. 39
Side impact air bag ..........................42
Window curtain air bag ....................43
Air-conditioning system
see Climate control
Air filter (display message) .............. 228
AIRMATIC (display message) ............ 229
AIRMATIC package ............................ 180
Air pressure see Tire pressure
Air vents
Important safety notes ..................141
Rear ............................................... 142
Setting ........................................... 141
Setting the center air vents ...........141
Setting the side air vents ...............141
Alarm system
see ATA (Anti-Theft Alarm system)
Anti-lock Braking System
see ABS (Anti-lock Braking System)
Anti-Theft Alarm system
see ATA (Anti-Theft Alarm system)
Anti-theft system
ATA (Anti-Theft Alarm system) .........69
Ashtray ............................................... 265
ASSYST PLUS see ASSYST PLUS service interval
display
ATA (Anti-Theft Alarm system)
Activating/deactivating ...................69
Function ........................................... 69
Switching off the alarm ....................69
Audio menu (on-board computer) .... 203
Audio system see separate operating instructions
Authorized Mercedes-Benz Center
see Qualified specialist workshop
AUTO lights
Display message ............................ 225
see Lights
Automatic headlamp mode .............. 115
Automatic transmission Automatic drive program ...............154
Changing gear ............................... 152
DIRECT SELECT lever .....................150
Display message ............................ 234
Driving tips .................................... 153
Emergency running mode ..............156
Kickdown ....................................... 153
Problem (malfunction) ...................156
Program selector button ................153
Pulling away ................................... 147
Shift ranges ................................... 154
Starting the engine ........................146
Steering wheel paddle shifters ......153
Trailer towing ................................. 153
Transmission position display ........151
Transmission positions ..................152
Automatic transmission
emergency mode ............................... 1564Index

DoorsAutomatic locking (on-board
computer) ...................................... 208
Automatic locking (switch) ............... 80
Display message ............................ 235
Emergency locking ........................... 81
Emergency unlocking .......................81
Opening (from inside) ......................80
Drinking and driving ......................... 165
Drinks holder see Cup holders
Drive program (automatic) ............... 154
Driver's door see Doors
Driver's seat
see Seats
Driving abroad
Mercedes-Benz Service .................287
Symmetrical low beam ..................114
Driving on flooded roads .................. 168
Driving safety systems 4ETS (Electronic Traction System) ...66
ABS (Anti-lock Braking System) .......65
BAS (Brake Assist System) ..............65
Distance warning system
(vehicles with DISTRONIC) ...............68
Electronic brake force distribution ...68
ESP ®
(Electronic Stability
Program) .......................................... 66
Important safety information ...........64
Overview .......................................... 64
Driving systems
Blind Spot Assist ............................ 189
Cruise control ................................ 170
Display message ............................ 229
DISTRONIC .................................... 173
Level control .................................. 181
PARKTRONIC ................................. 184
Rear axle level control ...................180
Rear view camera .......................... 187
Driving tips
Automatic transmission .................153
Brakes ........................................... 166
Break-in period .............................. 144
DISTRONIC .................................... 179
Downhill gradient ........................... 166
Drinking and driving .......................165Driving abroad ............................... 114
Driving on flooded roads ................168
Driving on wet roads ......................168
Exhaust check ............................... 166
Fuel ................................................ 165
General .......................................... 165
Hydroplaning ................................. 168
Icy road surfaces ........................... 170
Limited braking efficiency on
salted roads ................................... 167
Pedals ............................................ 165
Snow chains .......................... 169, 325
Symmetrical low beam ..................114
Towing a trailer .............................. 191
Wet road surface ........................... 167
DVD audio (on-board computer) ...... 203
E
EASY-ENTRY feature 3rd row of seats ............................. 103
Activating/deactivating .................209
Function/notes ............................. 108
EASY-EXIT feature
3rd row of seats ............................. 103
Crash-responsive ........................... 109
Function/notes ............................. 108
Switching on/off ........................... 209
EBD (electronic brake force
distribution) Display message ............................ 216
Function/notes ................................ 68
Electrical fuses
see Fuses
Electronic Brake force Distribution
see EBD (Electronic Brake force
Distribution)
Electronic Stability Program
see ESP ®
(Electronic Stability Program)
Electronic Traction System
see ETS/4ETS (Electronic
Traction System)
Emergency release
Driver's door .................................... 81
Fuel filler flap ................................. 158
Vehicle ............................................. 81
8Index

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.
ESP ®
(Electronic Stability Program)
Important safety notes
i See the "Important safety notes" section
( Y page 64).
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.
! Only operate the vehicle for a maximum
of ten seconds on a brake test
dynamometer. Switch off the ignition.
Application of the brakes by ESP ®
may
otherwise destroy the brake system.
! Function or performance tests may only
be performed on a 2-axle dynamometer. If
you wish to operate the vehicle on such a
dynamometer, please consult an
authorized Mercedes-Benz Center
beforehand. 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.
4ETS (Electronic Traction System)
i Observe the "Important safety notes"
section ( Y page 64).
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. In addition, more drive torque is
transferred to the wheel or wheels with
traction.
Traction control remains active if you
deactivate ESP ®
.
GWARNING
Traction control cannot reduce the risk of an
accident if you drive too fast. Traction control
cannot override the laws of physics.
Deactivating/activating ESP ®
i
Observe the "Important safety notes"
section ( Y page 64).
GWARNING
ESP ®
should not be deactivated during
normal driving other than in the
circumstances described below. Disabling
the system will reduce vehicle stability in
driving maneuvers.
Do not deactivate ESP ®
when the emergency
or spare wheel is mounted.
66Driving safety systemsSafety

ESP®
is activated automatically when the
engine is started.
It may be best to deactivate ESP ®
in the
following situations:
R when using snow chains
R in deep snow
R on sand or gravelGWARNING
Switch on ESP ®
immediately if one of the
previously stated conditions is no longer met.
Otherwise, ESP ®
cannot stabilize the vehicle
if it begins to lurch or when a wheel spins.
When you deactivate ESP ®
:
R ESP ®
no longer improves driving stability.
R the engine's torque is no longer limited and
the drive wheels can spin. The spinning of
the wheels results in a cutting action, which
provides better grip.
R traction control is still activated.
R ESP ®
still provides support when you
brake.
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ ESP®
warning lamp in
the instrument cluster flashes. In such
situations, ESP ®
will not stabilize the vehicle.
XTo deactivate: press button :.
The å ESP®
OFF warning lamp in the
instrument cluster lights up.GWARNING
When the å ESP®
OFF warning lamp is lit,
ESP ®
is deactivated.
If the ÷ ESP®
warning lamp and the
å ESP®
OFF warning lamp remain lit,
ESP ®
is not available due to a malfunction.
When ESP ®
is deactivated or not operational,
vehicle stability in standard driving
maneuvers is reduced.
Adapt your speed and driving to the prevailing
road conditions and to the non-operating
status of the ESP ®
.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated.
You could otherwise damage the drivetrain.
XTo activate: press button :.
The å ESP®
OFF warning lamp in the
instrument cluster goes out.
ESP ®
trailer stabilization
If your vehicle with trailer (vehicle/trailer
combination) begins to lurch, you can only
stabilize the vehicle/trailer combination by
depressing the brake firmly.
In this situation, ESP ®
assists you and can
detect if the vehicle/trailer combination
begins to lurch. ESP ®
slows the vehicle down
by braking and limiting the engine output until
the vehicle/trailer combination has
stabilized.
Trailer stabilization is active from a speed of
approximately 40 mph(65 km/h).
GWARNING
The system will not be able to assist when the
trailer jackknifes
R if the ESP ®
has switched off due to a
malfunction
R on wet or icy roads
R on roads with slippery surface
R in sand or gravel
Driving safety systems67SafetyZ

RThe use of the cruise control can be
dangerous on winding roads or in heavy
traffic because conditions do not allow safe
driving at a constant speed.
R The use of the cruise control can be
dangerous on slippery roads. Rapid
changes in tire traction can result in wheel
spin and loss of control.
R Deactivate the cruise control when driving
in fog.
The "Resume" function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.GWARNING
When cruise control brakes, the brake pedal
is pulled back (i.e. operated automatically).
The area around the pedal must not be
blocked by obstacles:
R Do not place any objects in the footwell.
R Ensure that floormats and carpets are fixed
securely. In particular, do not place several
floormats on top of one another.
R Do not place your foot under the brake
pedal, as it could become trapped.
Non-compliance could lead you to cause an
accident in which you and/or others could be
seriously injured.
Cruise control lever:To store the current speed or a higher
speed;To store the current speed or a lower
speed=To deactivate cruise control?To store the current speed or to call up
the last stored speed
When you activate cruise control, the stored
speed is shown in the status indicator of the
multifunction display:
R Canada only: e.g. ¯90 Km/h
Storing and maintaining the current
speed
You can store the current speed if you are
driving faster than 20 mph (30 km/h).
XAccelerate the vehicle to the desired
speed.XBriefly press the cruise control lever
up : or down ; to the pressure point.XRemove your foot from the accelerator
pedal.
Cruise control is activated. The vehicle
automatically maintains the stored speed.
i Cruise control may be unable to maintain
the stored speed on uphill gradients. The
stored speed is resumed when the gradient
evens out. Cruise control maintains the
stored speed on downhill gradients by
automatically applying the brakes.
Driving systems171Driving and parkingZ

conditions make it advisable to travel at a
constant speed.GWARNING
Use of the Distronic can be dangerous on
slippery roads. Rapid changes in tire traction
can result in wheel spin and loss of control.
The Distronic does not function in adverse
sight and distance conditions. Do not use the
Distronic during conditions of fog, heavy rain,
snow or sleet.
GWARNING
The Distronic cannot take weather conditions
into account. Switch off the Distronic or do
not switch it on if:
R roads are slippery or covered with snow or
ice. The wheels could lose traction while
braking or accelerating, and the vehicle
could skid.
R the Distronic system sensor cover is dirty
or visibility is diminished due to snow, rain
or fog, for example. The distance control
system functionality could be impaired.
Always pay attention to surrounding traffic
conditions even while the Distronic is
switched on. Otherwise, you may not be able
to recognize dangerous situations until it is
too late. This could cause an accident in which
you and/or others could be injured.
GWARNING
The "Resume" function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
GWARNING
Close attention to road and traffic conditions
is imperative at all times, regardless of
whether or not the Distronic is activated.
Use of the Distronic can be dangerous on
winding roads or in heavy traffic because
conditions do not allow safe driving at a
constant speed.
The Distronic will not react to stationary
objects in the roadway (e.g. a stopped vehicle
in a traffic jam or a disabled vehicle). The
Distronic will also not respond to oncoming
vehicles.
Switch off the Distronic
R when changing from the left to the right
lane if vehicles are moving more slowly in
the left lane
R when entering a turn lane or highway off
ramp
R in complex driving situations, such as in
highway construction zones
In these situations, the Distronic will continue
to maintain the set speed unless deactivated.
The Distronic is designed and intended only
to maintain a set speed and keep a set
distance from moving objects in front of it.
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.174Driving systemsDriving and parking

ProblemPossible causes/consequences and M Solutions!
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds.GRisk of accident
EBD is faulty. Therefore, ABS, BAS, PRE-SAFE ®
, hill start assist and
ESP ®
trailer stabilization, for example, are also not available due
to a malfunction.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.$ (USA only)
J (Canada only)
֌!
The red brake warning
lamp, the yellow ESP ®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running.GRisk of accident
ABS and ESP ®
are faulty. As a result other systems, such as, BAS,
EBD, PRE-SAFE ®
, hill start assist and ESP ®
trailer stabilization...,
may also be unavailable due to a malfunction.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.÷
The yellow ESP ®
warning lamp flashes
while the vehicle is in
motion.GRisk of accident
ESP ®
or traction control has intervened because there is a risk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC is deactivated.
XOnly depress the accelerator pedal as far as necessary when
pulling away.XRelease the accelerator pedal while the vehicle is in motion.XAdapt your driving style to suit the road and weather conditions.XDo not deactivate ESP ®
.
For exceptions: ( Y page 66).Warning and indicator lamps in the instrument cluster241On-board computer and displaysZ

Notes on regularly inspecting wheels
and tiresGWARNING
Regularly check the tires for damage.
Damaged tires can cause tire inflation
pressure loss. As a result, you could lose
control of your vehicle.
Worn, old tires can cause accidents. If the tire
tread is worn to minimum tread depth, or if
the tires have sustained damage, replace
them.
R Regularly check the wheels and tires of
your vehicle for damage (e.g. cuts,
punctures, tears, bulges on tires and
deformation or cracks or severe corrosion
on wheels) at least once a month, as well
as after driving off-road or on rough roads.
Damaged wheels can cause a loss of tire
pressure.
R Regularly check the tire tread depth and
the condition of the tread across the whole
width of the tire (Y page 323). If necessary,
turn the front wheels to full lock in order to
inspect the inner side of the tire surface.
R All wheels must have a valve cap to protect
the valve against dirt and moisture. Do not
mount anything onto the valve (such as tire
pressure monitoring systems) other than
the standard valve cap or other valve caps
approved by Mercedes-Benz for your
vehicle.
R Regularly check the pressure of all the tires
including the emergency spare wheel or the
spare wheel, particularly prior to long trips,
and correct the pressure as necessary
( Y page 325).
Tire tread
GWARNING
Although the applicable federal motor vehicle
safety laws consider a tire to be worn when
the tread wear indicators (TWI) become
visible at approximately 1
/ 16 in (1.6 mm), we
recommend that you do not allow your tires
to wear down to that level. As tread depth
approaches 1
/ 8 in (3 mm), the adhesion
properties on a wet road are sharply reduced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
Do not use tires that are excessively worn as
the tire traction on wet road surfaces
decreases significantly when the tread depth
is less than 1
/ 8 inch (3 mm).
Tread wear indicators (TWI) are required by
law. Six indicators are positioned over the tire
tread. They are visible as soon as a tread
depth of approx. 1
/ 16 inch (1.6 mm) is
reached. If this is the case, the tire is so worn
that it must be replaced.
The recommended tread depth for summer
tires is at least 1
/ 8 inch (3 mm). The
recommended tread depth for winter tires is
at least 1
/ 6 inch (4 mm).
Bar marking
: for tread wear is integrated
into the tire tread.
Notes on selecting, mounting and
replacing tires
R Only mount tires and wheels of the same
type and make.
R Only mount tires of the correct size onto
the wheels.
R After mounting new tires, run them in at
moderate speeds for the first 60 miles
Operation323Wheels and tiresZ

Maximum tire load : is the maximum
permitted weight for which the tire is
approved.
Further information on tire loads
( Y page 339).
Uniform Tire Quality Grading
Standards
Overview of Tire Quality Grading
Standards
The Uniform Tire Quality Grading is a U.S.
Government requirement. Their purpose is to
provide drivers with consistent and reliable
information regarding tire performance. Tire
manufacturers are required to grade tires
using three performance factors: tread
wear :, tire traction ;, and temperature
resistance =. Although not a Government of
Canada requirement, all tires made for sale in
North America have these grades branded on
the sidewall.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
Where applicable, the tire grading
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
For example:
Tread wearTractionTemperature200AAAAll passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Tread wear
The tread wear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
U.S. government course. For example, a tire
graded 150 would wear one and one-half
times as well on the government course as a
tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly from
the norm, due to variations in driving habits,
service practices and differences in road
characteristics and climate conditions.
Traction
GWARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance.
GWARNING
If ice has formed on the road, tire traction will
be substantially reduced. Under such weather
conditions, drive, steer and brake with
extreme caution.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road
surfaces.
338Uniform Tire Quality Grading StandardsWheels and tires

For further information on the load bearing
index, see Load index ( Y page 342).
Speed index: speed index B specifies the
approved maximum speed of the tire.GWARNING
Even when permitted by law, never operate a
vehicle at speeds greater than the maximum
speed rating of the tires.
Exceeding the maximum speed for which tires
are rated can lead to sudden tire failure,
causing loss of vehicle control and possibly
resulting in an accident and/or serious
personal injury and possible death, for you
and for others.
Regardless of the speed index always observe
the speed limits. Drive carefully and adapt
your driving style to the traffic conditions.
Summer tiresIndexSpeed ratingQUp to 100 mph (160 km/h)RUp to 106 mph (170 km/h)SUp to 112 mph (180 km/h)TUp to 118 mph (190 km/h)HUp to 130 mph (210 km/h)VUp to 149 mph (240 km/h)WUp to 168 mph (270 km/h)YUp to 186 mph (300 km/h)ZR...YUp to 186 mph (300 km/h)ZR...(..Y)Above 186 mph (300 km/h)ZRAbove 149 mph (240 km/h)
R Optionally, tires with a maximum speed of
over 149 mph (240 km/h) may have "ZR"
in the size description depending on the
manufacturer (e.g. 245/40 ZR 18).
The service specifications consist of load
bearing index A and speed index B.
R If the size description of your tire includes
"ZR" and there are no service
specifications, ask the tire manufacturer in
order to find out the maximum speed.
If a service specification is available, the
maximum speed is limited according to the
speed index in the service specification.
Example: 245/40 ZR 18 97 Y. In this
example, "97 Y" is the service specification.
The letter "Y" represents the speed index
and the maximum speed of the tire is
limited to 186 mph (300 km/h).
R Every tire that has a maximum speed above
186 mph (300 km/h) must have "ZR" in the
size description and the service
specification must be given in brackets.
Example: 275/40 ZR 18 (99 Y). The speed
index "(Y)" shows that the maximum speed
of the tire is above 186 mph (300 km/h).
Ask the tire manufacturer to find out the
maximum speed.All-weather tires and winter tiresIndexSpeed ratingQ M+S 38Up to 100 mph (160 km/h)T M+S38Up to 118 mph (190 km/h)H M+S 38Up to 130 mph (210 km/h)V M+S38Up to 149 mph (240 km/h)
i
Not all tires that have the M+S
identification offer the driving
characteristics of winter tires. Winter tires
have, in addition to the M+S identification,
the i snow flake symbol on the tire
sidewall. Tires with this identification fulfill
the requirements of the Rubber
Manufacturers Association (RMA) and the
Rubber Association of Canada (RAC)
regarding the tire traction on snow and
38 Or M+S i for winter tires.Tire labeling341Wheels and tiresZ