warning light MERCEDES-BENZ R-Class 2011 W251 Repair Manual

Brakes
Important safety guidelinesGWarning
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
GWarning
Make sure that you do not endanger other
road users when you apply the brakes.
Downhill gradients
! On long and steep gradients, you must
reduce the cargo on the brakes by shifting
to a lower gear in good time. This allows
you to take advantage of engine braking
and helps you to avoid overheating the
brakes and wearing them out excessively.
When you take advantage of engine
braking, a drive wheel may not turn for
some time, e.g. on a slippery road surface.
This could cause damage to the drive train.
Such damage is not covered by the
Mercedes-Benz warranty.
Heavy and light loads
GWarning
Depressing the brake pedal constantly results
in excessive and premature wear to the brake
pads.
It may also cause the brakes to overheat,
seriously impairing their effectiveness. It may
then not be possible to stop the vehicle in
sufficient time to avoid an accident.
If the brakes have been subjected to a heavy
cargo, do not stop the vehicle immediately,
but drive on for a short while. This allows the
airflow to cool the brakes more quickly.
Wet roadsGWarning
After driving in heavy rain for some time
without applying the brakes or through water
deep enough to wet brake components, the
first braking action may be somewhat
reduced. You have to depress the brake pedal
more firmly. Maintain a safe distance from
vehicles in front.
After driving on a wet road or having the
vehicle washed, brake firmly while paying
attention to the traffic conditions. This will
warm up the brake discs, thereby drying them
more quickly and protecting them against
corrosion.
Limited braking performance on salt
treated roads
GWarning
The layer of salt on the brake discs and the
brake pads/linings may cause a delay in the
braking effect, resulting in a significantly
longer braking distance, which could lead to
an accident.
To avoid this danger, you should:
R occasionally brake carefully, without
putting other road users at risk, when you
are driving on salted roads. This helps to
remove any salt that may have started to
build up on the brake discs and the brake
pads/linings.
R maintain a greater distance to the vehicle
ahead and drive with particular care.
R carefully apply the brakes at the end of a
trip and immediately after commencing a
new trip, so that salt residues are removed
from the brake discs.
Maintenance of the brakes
! If the brake warning lamp lights up in the
instrument cluster and you hear a warning
tone, even though the parking brake has
been released, the brake fluid level may be
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too low. Observe additional warning
messages in the multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked
immediately. This work should be carried
out at an authorized Mercedes-Benz
Center.
All checks and maintenance work on the
brake system must be carried out at a
qualified specialist workshop. Contact an
authorized Mercedes-Benz Center.
Only install brake pads and use brake fluid
recommended by Mercedes-Benz.GWarning
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that safe
braking is substantially impaired. This could
result in an accident.
! A function or performance test may only
be carried out on a two-axle dynamometer.
If you are planning to have the vehicle
tested on such a dynamometer, contact an
authorized Mercedes-Benz Center to
obtain further information first. Otherwise,
the drive train or the brake system may
suffer damage.
! As the ESP ®
system operates
automatically, the engine and the ignition
must be switched off (SmartKey in position
0 or 1 in the ignition lock or Start/Stop
button in position 0 or 1) while the parking
brake is being tested on a brake
dynamometer (maximum 10 seconds).
Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
If your brake system is only subjected to
moderate loads, you should regularly test
your brake system's function by forcefully
depressing the brake pedal when driving at
high speed. This also improves the brake
pads' friction.GWarning
Make sure that you do not endanger other
road users when you apply the brakes.
You can find a description of Brake Assist
(BAS) on ( Y page 68).
Parking brake
If you drive on wet roads or dirt-covered
surfaces, road salt and/or dirt could get into
the parking brake.
In order to prevent corrosion and a reduction
in the braking power of the parking brake,
observe the following:
R gently depress the parking brake from time
to time before beginning the journey.
R drive approximately 110 yd (100 m)
without exceeding a speed of 12 mph
(20 km/h).
GWarning!
While performing this procedure please
assure that the vehicle is stopped before
applying the parking brake. Otherwise the
rear wheels could lock up. You could lose
control of the vehicle and cause an accident.
In addition, the vehicle’s brake lights do not
light up when the parking brake is engaged.
Make sure not to endanger any other road
users when you engage the parking brake.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning occurring, even if:
R you drive at low speeds
R the tires have adequate tread depth
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For this reason, in the event of heavy rain or
in conditions in which hydroplaning can occur
you must drive in the following manner:
R Lower your speed
R Avoid ruts
R Brake carefully
Driving on flooded roads
! Do not drive through flooded areas.
Check the depth of any water before driving
through it. Drive slowly through standing
water. Otherwise, water may enter the
vehicle interior or the engine compartment.
This can damage the electronic
components in the engine or the automatic
transmission. Water can also be drawn in
by the engine's air suction nozzles and this
can cause engine damage.
Prevent water from entering the vehicle
interior or engine compartment. If you have
to drive through standing water, please note
that:
R the maximum permissible still water depth
is 10 in. (25 cm).
R you should drive no faster than at walking
pace.
i Vehicles with the AIRMATIC package:
if you have set the raised vehicle level
before driving through standing water, the
maximum water depth is 12 in. (30 cm).
Winter driving
General notes
Have your vehicle winterproofed at a qualified
specialist workshop, e.g. at an authorized
Mercedes-Benz Center, at the onset of
winter.
Observe the notes in the "Winter operation"
section ( Y page 172).
i Vehicles with a diesel engine: do not
cover the radiator, e.g. with a protective
cover. The measuring function of the
Onboard Diagnosis System may otherwise
provide inaccurate values. Some of these
values are required by law and must
therefore always be accurate.
Slippery road surfacesGWarning
If the vehicle becomes stuck in snow, make
sure snow is kept clear of the exhaust pipe
and from around the vehicle with the engine
running. Otherwise, deadly carbon monoxide
(CO) gases may enter vehicle interior
resulting in unconsciousness and death.
To assure sufficient fresh air ventilation, open
a window slightly on the side of the vehicle
not facing the wind.
GWarning!
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
GWarning
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
You should drive particularly carefully on
slippery road surfaces. Avoid sudden
acceleration, steering and braking
maneuvers. Do not use cruise control.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
XShift the transmission to position N.
i
For more information on driving with
snow chains, see .
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Setting in 5 mph (Canada: 10 km/h)
incrementsXBriefly press the cruise control lever
beyond the pressure point, up : for a
higher speed or down ; for a lower speed.
The last speed stored is increased or
reduced.
Storing the current speed or calling up
the last speed stored
GWarning
The set speed stored in memory should only
be set again if prevailing road conditions and
legal speed limits permit. Possible
acceleration or deceleration differences
arising from returning to the preset speed
could cause an accident and/or serious injury
to you and others.
XBriefly pull the cruise control lever towards
you ?.XRemove your foot from the accelerator
pedal.
DISTRONIC is activated and accepts the
current speed if it is activated for the first
time, or adjusts the vehicle's speed to the
last speed stored.
Setting the specified minimum distance
You can set the specified minimum distance
for DISTRONIC by varying the time span
between one and two seconds. This time span
determines the distance that DISTRONIC
should maintain from the vehicle in front,
depending on the road speed. You can see
this distance in the multifunction display
( Y page 180).
GWarning!
It is up to the driver to exercise discretion to
select the appropriate setting given road
conditions, traffic, driver's preferred driving
style and applicable laws and driving
recommendations for safe following distance.
XTo increase: turn thumbwheel ; towards
= .
DISTRONIC then maintains a greater
distance between your vehicle and the
vehicle in front.XTo decrease: turn thumbwheel ;
towards :.
DISTRONIC then maintains a shorter
distance between your vehicle and the
vehicle in front.
i Make sure that you maintain the
minimum distance to the vehicle in front as
required by law. Adjust the distance to the
vehicle in front if necessary.
DISTRONIC displays in the
speedometer
When DISTRONIC is activated, one or
two segments in the set speed range light up.
i For design reasons, the speed displayed
in the speedometer may differ slightly from
the speed set for DISTRONIC.
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If DISTRONIC detects a vehicle in front,
segments ; between the speed of the
vehicle in front : and stored speed = light
up.GWarning!
An intermittent warning sounds and the
distance warning lamp · in the instrument
cluster is illuminated if the Distronic system
calculates that the distance to the vehicle
ahead and your vehicle’s current speed
indicate that the Distronic will not be capable
of slowing the vehicle sufficiently to maintain
the preset following distance, which creates
a danger of a collision.
Immediately brake the vehicle to increase
your distance to the preceding vehicle. The
warning sound is intended as a final caution
in which you should intercede with your own
braking inputs to avoid a potentially
dangerous situation. Do not wait for the
operation of the warning signal to intercede
with your own braking. This will result in
potentially dangerous emergency braking
which will not always result in an impact being
avoided.
Tailgating increases the risk of an accident.
GWarning
DISTRONIC brakes your vehicle with a
maximum deceleration of 13 ft/s 2
(4 m/s 2
).
This corresponds to approximately 40% of
your vehicle's maximum possible braking
power.
You must apply the brakes yourself to avoid a
collision. DISTRONIC brakes the vehicle to
restore the set distance to the vehicle in front
or to restore the set speed. In this case, the
brake pedal is depressed automatically,
which can be seen by a movement of the
brake pedal.
Always keep the driver's footwell clear,
including the area under the brake pedal.
Objects in this area may impair pedal
movement and cause the DISTRONIC braking
function to malfunction.
Do not place your foot under the brake pedal
– your foot could become caught.
DISTRONIC displays in the
multifunction displayXPress the V or U button to select the
DISTRONIC menu (Y page 201).
Display when DISTRONIC is switched off
When DISTRONIC is deactivated, you will see
the following in the multifunction display:
:Vehicle in front, if detected;Distance indicator, displaying current
distance to the vehicle in front=Specified minimum distance to the
vehicle in front, adjustable?Own vehicle
Display when DISTRONIC is activated
After this time, you will see the following in
the multifunction display while DISTRONIC is
activated:
:DISTRONIC activated;Stored speed
When activating DISTRONIC and when setting
the speed, stored speed ; appears for
around five seconds.
After approximately five seconds, current
saved speed ; is shown in the status
indicator in the multifunction display
DTR XXX Miles .
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Top view
Front sensors
CenterApprox. 40 in (100 cm)CornersApprox. 24 in (60 cm)
Rear sensors
CenterApprox. 48 in (120 cm)CornersApprox. 32 in (80 cm)
! When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars.
PARKTRONIC does not detect such objects
when they are in the immediate vicinity of
the vehicle. You could damage the vehicle
or the objects.
Ultrasonic sources such as an automatic
car wash, a truck's compressed-air brakes
or a pneumatic drill could cause
PARKTRONIC to malfunction.
Minimum distance
CenterApprox. 8 in (20 cm)CornersApprox. 6 in (15 cm)
If there is an obstacle within this range, all
warning displays light up and a warning tone
sounds. If the distance falls below the
minimum, the distance may no longer be
shown.
Warning displays
The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is located
on the dashboard above the center air vents.
The warning display for the rear area is in the
roof lamp in the rear compartment.
Warning display for the front area
:Segments on the left-hand side of the
vehicle;Segments on the right-hand side of the
vehicle=Segments showing operational readiness
The warning display for each side of the
vehicle is divided into five yellow and two red
segments. PARKTRONIC is operational if
yellow segments showing operational
readiness = light up.
The selected transmission position
determines which warning display is active
when the engine is running.
Transmission
positionWarning displayDFront area activatedR or NRear and front areas
activatedPNo areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle.
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From the:
R sixth segment onwards, you will hear an
intermittent warning tone for
approximately two seconds.
R seventh segment onwards, you will hear a
warning tone for approximately two
seconds. This indicates that you have now
reached the minimum distance.
Deactivating/activating PARKTRONIC:To deactivate/activate PARKTRONIC;Indicator lamp
If indicator lamp ; lights up, PARKTRONIC is
deactivated.
Towing a trailer
PARKTRONIC is deactivated for the rear area
when you establish an electrical connection
between your vehicle and a trailer.
! Remove the detachable ball coupling if
the trailer tow hitch is not required.
PARKTRONIC measures the minimum
detection range to an obstacle from the
bumper, not the ball coupling.
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Problems with PARKTRONICProblemPossible causes/consequences and M SolutionsOnly the red segments
in the PARKTRONIC
warning displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is
deactivated after
approximately
20 seconds and the
indicator lamp in the
PARKTRONIC button
lights up.PARKTRONIC has malfunctioned and has switched off.XIf problems persist, have PARKTRONIC checked at a qualified
specialist workshop.Only the red segments
in the PARKTRONIC
warning displays are lit.
PARKTRONIC is
deactivated after
approximately 20
seconds.The PARKTRONIC sensors are dirty or there is interference.XClean the PARKTRONIC sensors ( Y page 287).XSwitch the ignition back on.The problem may be caused by an external source of radio or
ultrasound waves.XSee if PARKTRONIC functions in a different location.Rear view camera
Important safety guidelines
The rear view camera is an optical parking aid.
It shows the area behind your vehicle in the
COMAND APS display.
GWarning!
Make sure no persons or animals are in or
near the area in which you are parking/
maneuvering. Otherwise, they could be
injured.
The rear view camera is located in the handle
strip of the tailgate.
:Rear view camera
View through the camera
The area behind the vehicle is displayed as a
mirror image, as in the rear-view mirror.
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GWarning!
The rear view camera is only an aid and may
display obstacles
R from a distorted perspective
R inaccurately
R may not display obstacles at all
The rear view camera does not relieve you of
the responsibility to be cautious. Take care
and pay careful attention. The rear view
camera may not show objects which are
R very close to the rear bumper
R under the rear bumper
R above the tailgate handle
You are responsible for safety at all times and
must continue to pay attention to the
immediate surroundings when parking and
maneuvering. This includes the area behind,
in front of, and beside the vehicle. Otherwise
you could endanger yourself and/or others.
GWarning!
The rear view camera either will not function
or will not function to its full capability if
R the tailgate is open
R it is raining very hard, snowing or foggy
R it is night or you are parking/maneuvering
your vehicle in an area where it is very dark
R the camera is exposed to a very bright white
light
R the immediate surroundings are
illuminated with fluorescent light (the
display may flicker)
R there is a sudden change in temperature,
e.g. if you drive into a heated garage from
the cold (lens condensation)
R the camera lens is dirty or covered
R the rear of your vehicle is damaged
In this case, have the position and setting
of the camera checked by a qualified
specialist workshop. Mercedes-Benz
recommends that you contact a Mercedes-
Benz Center for this purpose.
Do not use the rear view camera in these
situations. Otherwise you could injure
yourself or others and/or damage property
including your vehicle while parking/
maneuvering.
Activating the rear view cameraXMake sure that the key is in position 2 in
the ignition lock.XMake sure that the "rear view camera"
function is selected in COMAND APS; see
the separate operating instructions for
COMAND APS.XEngage reverse gear.
The area behind the vehicle is shown in the
COMAND APS display with guide lines.
Guide lines in the COMAND APS display
GWarning!
Use of rear view camera can be dangerous if
you are color-blind or have impaired color
vision.
Only use rear view camera if you can see and
distinguish all colored guidelines shown by
rear view camera on the COMAND system
display.
GWarning
Please note that objects that do not touch the
ground may appear to be further away than
they actually are, for example:
R the bumper of a vehicle parked behind you
R the trailer drawbar
R the ball coupling of a trailer tow hitch
R the rear end of a truck
R a slanted post
In such cases, you should not use the guide
lines to judge the distance. You may misjudge
the distance, which increases the risk of
impacting the objects.
Even if the object you approach is directly on
the ground, do not approach the object any
closer than the red guide line.
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GWarning
Blind Spot Assist monitors certain areas in the
immediate vicinity of your vehicle. Vehicles
that approach and drive past at high speeds
are not detected. There is no display and no
warning.
If the lanes are very wide, it may not be
possible to monitor the complete width of the
neighboring lane. For this reason, vehicles in
the next lane may not be detected, especially
if they are driving in a staggered formation.
This may be the case if vehicles are driving at
that edge of their lane which is furthest away
from your vehicle.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
If the lanes are narrow, the system may be
unable to distinguish the neighboring lane
from the one beyond it. For this reason, the
system may indicate vehicles in the farther
lane, especially if the vehicles are driving in a
staggered formation in different lanes. In
particular, this may be the case if the vehicles
are driving at that edge of their lane which is
nearest your vehicle.
Due to the nature of the system:
R warnings may be issued unnecessarily
when driving close to crash barriers or
similar solid lane borders.
R the warning may be interrupted when
traveling next to long vehicles for extended
periods.
The two sensors for Blind Spot Assist are
integrated into the sides of the rear bumper.
Make sure that the bumper is free of dirt, ice
or slush around the sensors. For example, the
radar sensors must not be covered by bicycle
racks or overhanging loads. In the event of a
severe impact or damage to the bumpers,
have the function of the radar sensors
checked at a qualified specialist workshop,
e.g. an authorized Mercedes-Benz Center.
Blind Spot Assist may otherwise not work
properly.
Information and warning display:Yellow indicator lamp/red warning lamp
If Blind Spot Assist is switched on, indicator
lamps : in the exterior mirrors light up
yellow up to a speed of 20 mph (30 km/h). At
speeds above 20 mph (30 km/h), the
indicator lamp goes out and Blind Spot Assist
is operational.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
20 mph (30 km/h), warning lamp : on the
corresponding side lights up red. This warning
is always emitted when a vehicle enters the
blind spot monitoring range from behind or
from the side. When you overtake a vehicle,
the warning only occurs if the difference in
speed is less than 7 mph (12 km/h).
The yellow indicator lamp goes out if the
reverse gear is engaged. In this event, Blind
Spot Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
GWarning
Blind Spot Assist is not active at speeds under
approximately 20 mph (30 km/h). The
indicator lamps in the exterior mirrors are
yellow. Vehicles in the monitoring range are
then not indicated.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
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