2012 MERCEDES-BENZ B-CLASS warning

Display messages Possible causes/consequences and
M Solutions¥
Check Washer Fluid The washer fluid level in the washer fluid reservoir has dropped
below the minimum.
i
If you do
not mix antifreeze with the washer fluid in the winter
months, then the washer fluid could freeze in the washer fluid
reservoir. In this case the Check Washer Fluid display
message could also be shown in the multifunction display.
X Add washer fluid ( Y page 269).Wiper
Malfunctioning The windshield wipers are malfunctioning.
X
Visit a qualified specialist workshop. Hazard Warning
Flashers
Malfunctioning The hazard warning lamps are faulty.
X
Visit a qualified specialist workshop. SmartKey
Display messages Possible causes/consequences and
M Solutions+
Key Does Not
Belong to Vehicle You have put the wrong SmartKey in the ignition lock.
X
Use the correct SmartKey. +
Take Your
Key

from
Ignition The SmartKey is in the ignition lock.
X
Remove the SmartKey. +
Obtain a New Key The SmartKey needs to be replaced.
X
Visit a qualified specialist workshop. Display messages
223
On-board computer and displays Z
ProCarManuals.com

Warning and indicator lamps in the instrument cluster
Seat belts
Problem Possible causes/consequences and
M Solutionsü
After starting the
engine, the red seat
belt warning
lamp
lights
up for six seconds. The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.
X
Fasten your seat belt ( Y page 45).ü
After starting the
engine, the red seat
belt warning
lamp

lights
up. In addition, a
warning tone sounds
for up to six seconds. The driver's seat belt is not fastened.
X
Fasten your seat belt ( Y page 45).
The warning tone ceases. ü
The red seat belt
warning lamp lights up
after the engine starts,
as soon as the driver's
or the front-passenger
door is closed.
The driver or front passenger has not fastened their seat belt.
X
Fasten your seat belt ( Y page 45).
The warning lamp goes out. There are objects on the front-passenger seat.
X
Remove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out. ü
The red seat belt
warning lamp flashes
and an intermittent
audible warning
sounds.
The driver or front passenger has not fastened their seat belt. In
addition,
you are

driving faster than 15 mph (25 km/h) or you have
briefly driven faster than 15 mph (25 km/h).
X Fasten your seat belt ( Y page 45).
The warning lamp goes out and the intermittent warning tone
ceases. There are objects on the front-passenger seat. In addition, you are
driving faster than 15 mph (25 km/h
) or you have briefly driven
faster than 15 mph (25 km/h ).
X Remove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out and the intermittent warning tone
ceases.224
Warning and indicator lamps in the instrument cluster
On-board computer and displays
ProCarManuals.com

Safety systems
Problem Possible causes/consequences and
M Solutions$ (USA only)
J (Canada only)
The red brake system
warning
lamp comes
on
while the engine is
running. A warning tone
also sounds. There is not enough brake fluid in the brake fluid reservoir.
G WARNING
The braking effect may be impaired.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road

and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away ( Y page 149).
X Do not add brake fluid. Adding more will not remedy the
malfunction.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. !
The yellow
ABS

warning
lamp is lit while the
engine is running. ABS (Anti-lock Braking System) is deactivated due to a
malfunction. BAS (Brake Assist), COLLISION PREVENTION
ASSIST, ESP
®
(Electronic Stability Program), the HOLD function
and hill start assist are therefore also deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not

operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic
transmission, will not be available. Warning and indicator lamps in the instrument cluster
225
On-board computer and displays Z
ProCarManuals.com

Problem Possible causes/consequences and
M Solutions!
The yellow
ABS
warning
lamp is lit while the
engine is running. ABS is temporarily unavailable. BAS, COLLISION PREVENTION
ASSIST,
ESP®
, EBD
(electronic brake force distribution), the HOLD
function and hill start assist are therefore also deactivated, for
example.
Possible causes are:
R Self-diagnosis is not yet complete.
R The on-board voltage may be insufficient.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not

operational, ESP ®
is unable to stabilize the vehicle.
There is a risk of an accident.
X Carefully drive on a suitable stretch of road, making slight
steering movements at a speed above 12 mph (20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.226
Warning and indicator lamps in the instrument cluster
On-board computer and displays
ProCarManuals.com

Problem Possible causes/consequences and
M Solutions!
The yellow
ABS
warning
lamp is lit while the
engine is running. A
warning tone also
sounds. EBD is malfunctioning. Therefore, ABS, BAS, COLLISION
PREVENTION
ASSIST, ESP®
,
the HOLD function and hill start assist
are unavailable, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not

operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit 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. ABS and ESP
®
are malfunctioning. Therefore, BAS, COLLISION
PREVENTION ASSIST, EBD,

the HOLD function and hill start assist
are also unavailable, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not

operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
227
On-board computer and displays Z
ProCarManuals.com

Problem Possible causes/consequences and
M Solutions÷
The yellow ESP
®
warning lamp flashes
while the vehicle is in
motion. 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 PLUS is deactivated.
X When pulling
away, only depress the accelerator pedal as far as
necessary.
X Ease off the accelerator pedal while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
For exceptions, see: ( Y page 62).å
The yellow ESP
®
OFF
warning lamp is

lit while
the engine is running. ESP
®
and ESP ®
trailer stabilization are deactivated. ESP ®
will not
stabilize the vehicle if it starts to skid or if a wheel starts to spin.
G WARNING
If ESP ®
is switched off, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Reactivate ESP ®
.
For exceptions, see: ( Y page 62).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Have ESP ®
checked at a qualified specialist workshop. ֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, COLLISION PREVENTION ASSIST, the HOLD function
and hill start assist are unavailable due to a malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not

operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.228
Warning and indicator lamps in the instrument cluster
On-board computer and displays
ProCarManuals.com

Problem Possible causes/consequences and
M Solutions֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, the HOLD function and hill start assist are temporarily
unavailable.
COLLISION PREVENTION ASSIST may also have failed.
ATTENTION ASSIST is deactivated.
Self-diagnosis is not yet complete.
G WARNING
The brake
system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not

operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Carefully drive on a suitable stretch of road, making slight
steering movements at a speed above 12 mph (20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
229
On-board computer and displays Z
ProCarManuals.com

Problem Possible causes/consequences and
M SolutionsF (USA only)
! (Canada only)
The red indicator lamp
for the electric parking
brake flashes or lights
up and/or the yellow
warning lamp for the
electric parking brake
lights up. X
Observe the additional display messages in the multifunction
display. 6
The red SRS warning
lamp is lit while the
engine is running.
There is a malfunction in the SRS (Supplemental Restraint
System).
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Drive on carefully.
X Have SRS checked at a qualified specialist workshop
immediately.
For further information about SRS, see (Y page 38). 230
Warning and indicator lamps in the instrument clusterOn-board computer and displays
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