instrument cluster MERCEDES-BENZ R-Class 2012 W251 User Guide

If the driver or front passenger have not
fastened their seat belt after 6 seconds and
the doors are closed, the 7 seat belt
warning lamp lights up.
R until the driver or the front passenger have
fastened their seat belts
R if a vehicle speed of 15 mph(25 km/h) is
exceeded once, a warning tone with
increasing intensity sounds additionally for
a maximum of 60 seconds or until the driver
or front passenger have fastened their seat
belts.
If the driver or front passenger undo their seat
belts during the journey, the 7 seat belt
warning lamp lights up and the warning tone
sounds again.
The warning tone ceases even if the driver or
front passenger have still not fastened their
seat belt after 60 seconds. The 7 seat belt
warning lamp stops flashing but continues to
be lit.
Once the vehicle is stationary, the warning
tone is reactivated and the 7 seat belt
warning lamp starts to flash again if the
vehicle speed exceeds 15 mph(25 km/h)
once.
The 7 seat belt warning lamp only goes
out if:
R both the driver and the front passenger
have fastened their seat belts.
or
R the vehicle is stationary and a door is open.
i For more information on the 7 seat
belt warning lamp, see "Warning and
indicator lamps in the instrument cluster,
seat belt" ( Y page 238).Emergency Tensioning Devices, seat
belt force limiters
The seat belts for the following seats are
equipped with ETDs and seat belt force
limiters:
R driver's and front-passenger seat
R the outer seats in the second row
R the seats in the third row
The ETDs tighten the seat belts in an accident,
pulling them close against the body.
The ETDs do not correct incorrect seat
positions or incorrectly fastened seat belts.
The ETDs do not pull vehicle occupants back
towards the backrest.
Seat belt force limiters, when triggered, help
to reduce the peak force exerted by the seat
belt on the vehicle occupant.
The seat belt force limiters for the front seats
are synchronized with the front air bags.
These take on a part of the deceleration force.
Thus, the force exerted on the occupant is
distributed over a greater area.
The ETDs can only be activated when:
R the ignition is switched on.
R the restraint systems are operational; see
"SRS warning lamp" ( Y page 38)
R the belt tongue is engaged in the buckle on
each of the lap-shoulder belts in the front.
R the front-passenger seat is occupied and
the belt tongue is engaged in the buckle on
the front-passenger side.
The ETDs on the outside seats in the second
row and on the seats in the third row are
triggered independently of the lock status of
the seat belts.
The ETDs are triggered depending on the type
and severity of an accident:
R if, in the event of a head-on or rear-end
collision, the vehicle decelerates or
accelerates rapidly in a longitudinal
Occupant safety55SafetyZ

section must never be exploited in a reckless
or dangerous manner which could jeopardize
the user's safety or the safety of others.
Always adjust your driving style to the
prevailing road and weather conditions and
keep a safe distance to other road users and
objects on the street.
If a driving system malfunctions, other driving
safety systems may also switch off. Observe
indicator and warning lamps that may come
on as well as messages in the multifunction
display that may appear.
i Please note that the driving safety
systems described only work as effectively
as possible when there is adequate contact
between the tires and the road surface. Pay
particular attention to the information
regarding tires, recommended minimum
tire tread depths etc. in the "Wheels and
tires" section ( Y page 322).
In wintry driving conditions, always use
winter tires (M+S tires) and if necessary,
snow chains. Only in this way will the
driving safety systems described in this
section work as effectively as possible.
ABS (Anti-lock Braking System)
Important safety notes
i Observe the "Important safety notes"
section ( Y page 64).
ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the
vehicle when braking.
ABS works from a speed of about
5 mph(8 km/h) upwards, regardless of road-
surface conditions. ABS works on slippery
surfaces, even when you only brake gently.
GWARNING
If the ABS malfunctions, other driving systems
such as the BAS or the ESP ®
are also switched
off. Observe indicator and warning lamps that
may come on as well as messages in the
multifunction display that may appear.
If the ABS malfunctions, the wheels may lock
during hard braking, reducing the steering
capability and extending the braking distance.
The ! warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
Braking
If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
XIf ABS intervenes: continue to depress the
brake pedal with force until the braking
situation is over.XTo make a full brake application:
depress the brake pedal with full force.
The pulsating brake pedal can be an
indication of hazardous road conditions, and
functions as a reminder to take extra care
while driving.
GWARNING
Do not pump the brake pedal. Use firm, steady
brake pedal pressure instead. Pumping the
brake pedal defeats the purpose of the ABS
and significantly reduces braking
effectiveness.
BAS (Brake Assist System)
i Observe the "Important safety notes"
section ( Y page 64).
BAS operates in emergency braking
situations. If you depress the brake pedal
quickly, BAS automatically boosts the braking
force, thus shortening the stopping distance.
XKeep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated.
Driving safety systems65SafetyZ

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

Trailers with a high center of gravity may tip
over before the system recognizes swaying of
the trailer.
Trailer stabilization does not work if ESP ®
is
deactivated or disengaged because of a
malfunction.
EBD (electronic brake force
distribution)
i Observe the "Important safety notes"
section ( Y page 64).
EBD monitors and controls the brake
pressure on the rear wheels to improve
driving stability while braking.
GWARNING
If EBD has malfunctioned, the braking system
remains available with full brake boosting
effect. However, the rear wheels can still lock,
e.g. under full braking. This could cause you
to lose control of your vehicle and cause an
accident. You should therefore adapt your
driving style to the different handling
characteristics.
XObserve the notes on warning and indicator
lamps ( Y page 240) as well as display
messages ( Y page 216).
Distance warning function (vehicles
with DISTRONIC)
This function provides a warning from a speed
of approximately 20 mph(30 km/h), if:
R for a period of several seconds, the
distance to the vehicle in front is too short
for the speed at which you are traveling.
The · distance warning lamp in the
instrument cluster will light up.
R you are rapidly approaching the vehicle in
front. An intermittent warning tone will
then sound and the · distance warning
lamp will light up in the instrument cluster.
You must apply the brakes yourself in order
to maintain the appropriate distance to the
vehicle in front and prevent a collision.GWARNING
If the distance warning lamp · in the
instrument cluster comes on while driving
and/or an intermittent warning sounds,
immediate attention on the part of the driver
is required. As required by the traffic
situation, apply the brakes and navigate
around a possible obstacle. However, do not
drive by relying on the distance warning
function, as this will result in an emergency
braking application. This will not always
enable you to avoid a collision, especially
when traveling on varying road surface
conditions and with varying driver reaction.
Complex driving situations are not always
fully recognized by the distance warning
function. This could result in wrong or missing
distance warnings.
XTo activate/deactivate: activate or
deactivate the distance warning function in
the on-board computer ( Y page 210).
After activation, the Ä symbol is
displayed in the lower multifunction
display.
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.68Theft deterrent locking systemsSafety

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).
Correct driver's seat position
Observe the safety guidelines on seat
adjustment ( Y page 97).
XCheck whether you have adjusted seat =
properly.
Electrical seat adjustment ( Y page 98)
When adjusting the seat, make sure:
R you are as far away from the driver's air
bag as possible.
R you are sitting in a normal upright
position.R you can fasten the seat belt properly.
R you have moved the backrest to an
almost vertical position.
R you have set the seat cushion angle so
that your thighs are gently supported.
R you can depress the pedals properly.XCheck whether the head restraint is
adjusted properly ( Y page 99).
When doing so, make sure that you have
adjusted the head restraint so that the back
of your head is supported at eye level by
the center of the head restraint.
Observe the safety guidelines on steering
wheel adjustment ( Y page 107).
XCheck whether steering wheel : is
adjusted properly.
Adjusting the steering wheel
manually( Y page 107)
Adjusting the steering wheel electrically
( Y page 108)
When adjusting the steering wheel, make
sure:
R you can hold the steering wheel with your
arms slightly bent.
R you can move your legs freely.
R you can see all the displays in the
instrument cluster clearly.
Observe the safety guidelines for seat belts
( Y page 51).
XCheck whether you have fastened seat
belt ; properly ( Y page 53).
The seat belt should:
R fit snugly across your body
R be routed across the middle of your
shoulder
R be routed in your pelvic area across the
hip jointsXBefore starting off, adjust the rear-view
mirror and the exterior mirrors96Correct driver's seat positionSeats, steering wheel and mirrors

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).
Exterior lighting
Important safety notes
For reasons of safety, Mercedes-Benz
recommends that you drive with the lights
switched on even during the daytime. In some
countries, operation of the headlamps varies
due to legal requirements and self-imposed
obligations.
Information about driving abroad
Converting to symmetrical low beam
when driving abroad: switch the headlamps
to symmetrical low beam in countries in
which traffic drives on the opposite side of the
road to the country where the vehicle is
registered. This prevents glare to oncoming
traffic. Symmetrical lights do not illuminate
as large an area of the edge of the road.
Have the headlamps converted at a qualified
specialist workshop, e.g. an authorized
Mercedes-Benz Center, as close to the border
as possible before driving in these countries.
Converting to asymmetrical low beam
after returning: have the headlamps
converted back to asymmetrical low beam at
a qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center, as soon as
possible after crossing the border again.
Light switch
Operation1 WLeft-hand standing lamps2XRight-hand standing lamps3$Lights off/daytime running lamps4ÃAutomatic headlamp mode/daytime
running lamps5 TParking lamps, license plate and
instrument cluster lighting6 LLow-beam/high-beam headlamps7RVehicles without front fog lamps:
rear fog lamp7 NVehicles with front fog lamps: front
fog lamp8 RVehicles with front fog lamps: rear
fog lamp
The turn signals, high-beam headlamps and
the high-beam flasher are operated using the
combination switch ( Y page 117).
! Switch off the parking lamps and standing
lamps when you leave the vehicle. This
prevents the battery from discharging.
The exterior lighting (except the parking/
standing lamps) switches off automatically if
you:
R remove the SmartKey from the ignition lock
R open the driver's door with the SmartKey
in position 0
If you hear a warning tone when you leave the
vehicle, the lights may still be switched on.
114Exterior lightingLights and windshield wipers

XTurn the light switch to $ or à .
or
XIf the rear fog lamp is switched on: press
the light switch in to the stop.
Low-beam headlamps
XTo switch on the low-beam headlamps:
turn the SmartKey in the ignition lock to
position 2 or start the engine.XTurn the light switch to L.
The L indicator lamp in the instrument
cluster lights up.XTo switch off the low-beam
headlamps: turn the light switch to $.
Daytime running lamps
Daytime running lamps in Canada
The "daytime running lamps" function is
required by law in Canada. It cannot therefore
be deactivated.
XTurn the light switch to $ or à .
With the engine running: depending on the
ambient light, the daytime running lamps or
the low-beam headlamps are switched on.
When the low-beam headlamps are
activated, the T indicator lamp on the
light switch and the L indicator lamp in
the instrument cluster light up.
If the light switch is set to $ or à , you
cannot activate the high-beam headlamps.
Turn the light switch to L when driving at
night. You can switch on the high-beam
headlamps in this position.
When the engine is running and the vehicle is
stationary: if you move the selector lever from
a driving position to N or P, the low-beam
headlamps go out after three minutes.
When the engine is running and the vehicle is
stationary: if you turn the light switch
to T , the parking lamps and the low-beam
headlamps are switched on.
Daytime running lamps in the USA
In the USA, the daytime running lamps are
deactivated upon delivery from the factory.XTo activate the daytime running
lamps: activate the daytime running lamps
function in the on-board computer
( Y page 206).XTurn the light switch to $ or à .
With the engine running: the low-beam
headlamps are switched on. The T
indicator lamp on the light switch and the
L indicator lamp in the instrument
cluster light up.
It is only possible to activate the high-beam
headlamps if the brightness of the ambient
light is at a low level.
However, the high-beam flasher can always
be used.
If the engine is running and you turn the light
switch to T or L , the manual settings
take precedence over the daytime running
lamps.
Automatic headlamp mode
XTo switch on automatic headlamp
mode: turn the light switch to Ã.
SmartKey in position 1 in the ignition lock:
the parking lamps are switched on or off
automatically depending on the brightness
of the ambient light.
With the engine running: depending on the
brightness of the ambient light, the daytime
running lamps 10
or the low-beam
headlamps are switched on or off
automatically.
When the low-beam headlamps are
switched on, the L indicator lamp in the
instrument cluster lights up.GWARNING
If the light switch is set to Ã, the low-beam
headlamps will not come on automatically if
it is foggy. This could endanger you and
10 Only if daytime running lamps have been activated via the on-board computer.Exterior lighting115Lights and windshield wipersZ

others. Therefore, turn the light switch to
L in fog.
The automatic headlamp feature is only an
aid. The driver is responsible for the vehicle's
lighting at all times.GWARNING
In low ambient lighting or foggy conditions,
only switch from position à to L with
the vehicle at a standstill in a safe location.
Switching from à to L will briefly
switch off the headlamps. Doing so while
driving in low ambient lighting conditions may
result in an accident.
Front fog lamps and rear fog lamp
Front fog lamps
Only vehicles with front fog lamps have the
"fog lamps" function.
GWARNING
If you suspect that driving conditions will be
foggy, turn the light switch to L before you
start your journey. Otherwise, your vehicle
may not be visible and you could endanger
yourself and others.
GWARNING
In low ambient lighting or foggy conditions,
only switch from position à to L with
the vehicle at a standstill in a safe location.
Switching from à to L will briefly
switch off the headlamps. Doing so while
driving in low ambient lighting conditions may
result in an accident.
XTo switch on the front fog lamps: turn
the SmartKey in the ignition lock to position
2 or start the engine.XTurn the light switch to L or T . If the
light switch is set to Ã, you cannot
switch on the fog lamps.XPull the light switch out to the first detent.
The green N indicator lamp on the light
switch lights up.XTo switch off the front fog lamps: press
the light switch in as far as it will go.
The green N indicator lamp on the light
switch goes out.
Rear fog lamp
XTo switch on (vehicles with front fog
lamps): turn the SmartKey in the ignition
lock to position 2 or start the engine.XTurn the light switch to L or T . When
the light switch is set to Ã, you cannot
switch on the rear fog lamp.XTurn the light switch to L. When the
light switch is set to T, you cannot
switch on the rear fog lamp.XPull the light switch out to the second stop.
The yellow R indicator lamp on the light
switch lights up.XTo switch off the rear fog lamp: press the
light switch in as far as it will go.
The yellow R indicator lamp on the light
switch goes out.XTo switch on (vehicles without front fog
lamps): turn the SmartKey in the ignition
lock to position 2 or start the engine.XTurn the light switch to L. When the
light switch is set to Ã, you cannot
switch on the rear fog lamp.XTurn the light switch to L. When the
light switch is set to c, you cannot
switch on the rear fog lamp.XPull the light switch out to the stop.
The yellow R indicator lamp on the light
switch lights up.XPull the light switch out to the stop.
The yellow R indicator lamp in the
instrument cluster lights up.116Exterior lightingLights and windshield wipers

XTo switch off the rear fog lamp: press the
light switch in as far as it will go.
The yellow R indicator lamp on the light
switch goes out.XTo switch off the rear fog lamp: press the
light switch in as far as it will go.
The yellow R indicator lamp in the
instrument cluster goes out.
Headlamp cleaning system
The headlamps are cleaned automatically if
the "Wipe with washer fluid" function is
operated ten times while the lights are on and
the engine is running (Y page 124). When you
switch off the ignition, the automatic
headlamp cleaning system is reset and
counting is resumed from 0.
Combination switch
Turn signals
:High-beam headlamps;Right turn signal=High-beam flasher?Left turn signalXTo indicate briefly: press the combination
switch briefly to the pressure point in the
direction of arrow ; or ?.
The corresponding turn signal flashes three
times.XTo indicate: press the combination switch
beyond the pressure point in the direction
of arrow ; or ?.High-beam headlampsXTo switch on the high-beam headlamps:
turn the SmartKey in the ignition lock to
position 2 or start the engine.XTurn the light switch to L.XPress the combination switch beyond the
pressure point in the direction of
arrow :.
The K indicator lamp in the instrument
cluster lights up.XTo switch off the high-beam
headlamps: move the combination switch
back to its normal position.
The K indicator lamp in the instrument
cluster goes out.
High-beam flasher
XTo switch on: turn the SmartKey in the
ignition lock to position 1 or 2 or start the
engine.XPull the combination switch in the direction
of arrow =.
Hazard warning lamps
The hazard warning lamps automatically
switch on if:
R an air bag is deployed.
R the vehicle is slowed down severely from a
speed of over 45 mph (70 km/h) and comes
to a halt.
Exterior lighting117Lights and windshield wipersZ