2014 MERCEDES-BENZ B-CLASS HATCHBACK ECU

The following information is displayed:
R the length of the journey since the last
break
R the attention level determined by ATTEN-
TION ASSIST ( Attention level Attention level), dis-
played in a bar display in five levels from
high to low
R If ATTENTION ASSIST is unable to calculate
the attention level and cannot issue a warn-
ing, the System suspended
System suspended message
appears. The bar display then changes the
display, e.g. if you are driving at a speed
below 60 km/h or above 200 km/h.
Displaying Attention Level with colour
multifunction display You can have current status information dis-
played in the assistance menu (Y
page 242)
of the on-board computer.
X Select the assistance graphics display for
ATTENTION ASSIST using the on-board
computer (Y page 243).
The following information is displayed: R the length of the journey since the last
break
R the attention level determined by ATTEN-
TION ASSIST ( Attention level
Attention level), dis-
played in a bar display in five levels from
high to low
R If ATTENTION ASSIST is unable to calculate
the attention level and cannot issue a warn-
ing, the System suspended
System suspended message
appears. The bar display then changes the display, e.g. if you are driving at a speed
below 60 km/h or above 200 km/h.
Activating ATTENTION ASSIST X
Activate ATTENTION ASSIST using the on-
board computer (Y page 244).
The system determines the attention level
of the driver depending on the setting
selected:
Selection Standard Standard: the sensitivity with
which the system determines the attention
level is set to normal.
Selection Sensitive
Sensitive : the sensitivity is set
higher. The attention level detected by
ATTENTION ASSIST is adapted accordingly
and the driver is warned earlier.
Vehicles with black and white multifunc-
tion display: when ATTENTION ASSIST is
activated, the multifunction display in the sta- tus overview shows the Àsymbol.
Vehicles with colour multifunction dis-
play: when ATTENTION ASSIST is deactiva-
ted, the multifunction display in the assis-
tance graphic shows the ésymbol.
When ATTENTION ASSIST has been deactiva-
ted, it is automatically reactivated after the
engine has been switched off. The sensitivity selected corresponds to the last selection
activated (standard/sensitive).
Warning in the multifunction display If fatigue or increasing lapses in concentra-
tion are detected, a warning appears in the
multifunction display:
ATTENTION ASSIST ATTENTION ASSIST
Take a break!
Take a break! .
In addition to the message shown in the mul-
tifunction display, you will then hear a warn-
ing tone.
X If necessary, take a break.
X Confirm the message by pressing the a
button on the steering wheel.
On long journeys, take regular breaks in good time that allow for adequate recuperation. If
you do not take a break and ATTEN- Driving syste
ms
217Driving an d parking Z

!
Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound- ing of the overrun brake.
! Remove the installed adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumper and the adapter cable.
X Make sure that the transmission is in posi-
tion P.
X Apply the electric parking brake.
X Secure the trailer against rolling away.
X Remove the trailer cable and decouple the
trailer. Folding in the ball coupling
G
WARNING
If you release the ball coupling or it does not
engage correctly when folding in, it will swing out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstructed. Always make sure that the ball coupling engages when folding in.
Fold the ball coupling back in if you are not
using the trailer tow hitch.
The release wheel is located behind the left-
hand side trim panel in the boot.
X Place the protective covering on the ball
coupling. X
To open the cover: turn handle:anti-
clockwise, then fold down and remove
cover ;. X
Pull out release wheel =.
X Turn release wheel =anti-clockwise as far
as it will go.
The ball coupling disengages and folds in
behind the rear bumper. Indicator lamp ?
flashes. X
Press the ball coupling in the direction of
the arrow until it engages behind the
bumper.
The indicator lamp on the release knob and
the message in the multifunction display go
out. Trailer power supply
! You can connect accessories with a
power rating of up to 240 W to the perma-
nent power supply and with a power rating of up to 180 W to the power supply that is
switched on via the ignition lock. 228
Towing a trailerDriving and parking

The trailer battery may not be charged from
the power supply.
When it leaves the factory, your vehicle's
trailer socket is equipped with a permanent
power supply and a power supply that is
switched on via the ignition lock.
The permanent power supply is supplied via
trailer socket pin 9.
The power supply that is switched on via the
ignition lock is supplied via trailer socket pin
10.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest.
You can find more information about fitting
the trailer electrics at a qualified specialist
workshop.
X To switch the connected power supply
on or off: turn the key to position 2or 0
respectively (Y page 159). Failure check for LEDs
If LED lamps are fitted in the trailer, a mal-
function message may appear in the multi-
function display even if there is no fault. The
reason for the error message may be that the
current has fallen below the minimum of
50 mA.
To ensure reliable operation of the failure
indicator, each LED chain in the trailer lighting
must be guaranteed a minimum current of
50 mA. Trailer with 7-pin connector
General notes Trailer with 7-pin connector:
you can con-
nect to the 13-pin socket on the ball coupling
using an adapter or, if necessary, an adapter
cable. Both can be obtained at a qualified
specialist workshop. Fitting the adapter !
Make sure that there is sufficient cable
play so that the cable cannot become
detached when cornering.
! Remove the installed adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumper and the adapter cable. X
Open the socket cover.
X Insert the plug connector with lug :into
groove =on the socket.
X Turn bayonet connection ;clockwise to
the stop.
X Let the cover engage.
X If you are using an adapter cable, secure
the cable to the trailer with cable ties. Towing a trailer
229Driving and parking Z

If the ignition remains switched off for longer
than four hours, the ECO display will be auto-
matically reset.
Further information on the ECO display
(Y page 185).
Displaying the range and current fuel
consumption X
Press the =or; button on the steer-
ing wheel to select the Trip Tripmenu.
X Press the 9or: button to select
approximate range :and current fuel con-
sumption ;.
Approximate range :that can be covered is
calculated according to your current driving
style and the amount of fuel in the tank. If
there is only a small amount of fuel left in the
fuel tank, the display shows a vehicle being
refuelled Cinstead of approximate
range :.
Recuperation display =shows you if energy
has been recuperated from the kinetic energy
in overrun mode and saved in the battery.
Recuperation display =depends on the
engine installed and is therefore not available in all vehicles.
Digital speedometer X
Press the =or; button on the steer-
ing wheel to select the Trip Tripmenu.
X Press the 9or: button to select
digital speedometer ;.
A gearshift recommendation :Zcan also
be displayed.
Observe the information on gearshift rec-
ommendation :for manual transmission
(Y page 169) or for automatic transmission
(shifting manually) (Y page 175).
Resets values X
Press the =or; button on the steer-
ing wheel to select the Trip Tripmenu.
X Press the 9or: button to select the
function that you wish to reset.
X Press the abutton.
X Select :YesYesand press ato confirm.
You can reset the values of the following func-
tions:
R Trip meter
R "From start" trip computer
R "From reset" trip computer
R ECO display
If you reset the values in the "ECO display",
the values in the "From start" trip computer
are also reset. If you reset the values in the
"From start" trip computer, the values in the
"ECO display" are also reset. Navigation menu
Displaying navigation instructions In the
Navi Navimenu, the multifunction display
shows navigation instructions. Menus and submenus
237On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions The yellow
!warning lamp and the red !indicator lamp are
lit.
The electric parking brake is malfunctioning.
To release:
X Switch off the ignition and turn it back on.
X Release the electric parking brake manually.
or X Vehicles with manual transmission (automatic emergency
release): insert the seat belt in the belt buckle and accelerate
slightly more when pulling away.
X Vehicles with automatic transmission: release the electric
parking brake automatically (Y page 182).
If the electric parking brake still cannot be released: X Do not drive on.
X Consult a qualified specialist workshop. The red
!indicator lamp flashes and the yellow !warning
lamp is lit.
The electric parking brake is malfunctioning.
To release:
X Switch off the ignition and turn it back on.
X Release the electric parking brake manually.
To apply:
X Switch off the ignition and turn it back on.
X Apply the electric parking brake manually.
If the red !indicator lamp continues to flash:
X Do not drive on.
X Secure the vehicle against rolling away (Y page 363).
X Vehicles with manual transmission: engage first gear.
X Vehicles with automatic transmission: shift the selector
lever to P.
X Turn the front wheels towards the kerb.
X Consult a qualified specialist workshop. 256
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions !
Parking Parking
brake
brakeinop‐
inop‐
erative
erative The yellow
!warning lamp lights up. The red !indicator
lamp flashes for about ten seconds after the electric parking brake
has been applied or released. It then goes out or remains lit.
The electric parking brake is malfunctioning, e.g. because of over- voltage or undervoltage.
X Rectify the cause of the overvoltage or undervoltage, e.g. by
charging the battery or restarting the engine.
X Apply or release the electric parking brake.
If the electric parking brake still cannot be applied or released: X Switch off the ignition and turn it back on.
X Apply or release the electric parking brake.
If the electric parking brake still cannot be released: X Consult a qualified specialist workshop.
If it is still not possible to apply the electric parking brake: X Visit a qualified specialist workshop. The red
!indicator lamp flashes and the yellow !warning
lamp is lit.
It is not possible to apply the electric parking brake manually.
X Vehicles with manual transmission: engage first gear.
X Vehicles with automatic transmission: shift the selector
lever to P.
X Visit a qualified specialist workshop. J
Brake immediately Brake immediately Vehicles with manual transmission: a malfunction has occurred
while the HOLD function was activated.
A tone may also sound at regular intervals. If you attempt to lock the vehicle, the tone becomes louder.
You cannot start the engine.
X Paying attention to the traffic situation, immediately depress the
brake pedal firmly and hold until the display message disap-
pears.
X Secure the vehicle against rolling away (Y page 181).
You can restart the engine. 258
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
Braking efficiency 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 181).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the fault. #
Check brake pad Check brake pad
wear wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. G
Inoperative
Inoperative One or more main features of the Mercedes-Benz Connect system
are malfunctioning.
X Have the system checked at a qualified specialist workshop. Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
currently unavail‐ currently unavail‐
able See Owner's able See Owner's
Manual Manual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation
R the system is outside the operating temperature range
R the on-board voltage is too low
Once the causes listed above no longer apply, the display message goes out.
COLLISION PREVENTION ASSIST PLUS is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 181).
X Restart the engine. Collision Preven‐ Collision Preven‐
tion Assist Plus tion Assist Plus
inoperative inoperative COLLISION PREVENTION ASSIST PLUS is temporarily inoperative
due to a malfunction. Adaptive Brake Assist may also have failed.
X Visit a qualified specialist workshop. Display
messages
259On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions PRE-SAFE inopera‐
PRE-SAFE inopera‐
tive See Owner's tive See Owner's
Manual Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. Radar sensors
Radar sensors
dirty See Owner's dirty See Owner's
Manual Manual At least one of the following driving systems or driving safety sys-
tems is temporarily restricted or inoperative:
R COLLISION PREVENTION ASSIST PLUS
R DISTRONIC PLUS
Possible causes:
R the sensors in the radiator trim and/or in the bumpers are dirty
R the function of the driving system and/or driving safety system
is impaired due to heavy rain or snow
A warning tone also sounds.
Once the causes listed above no longer apply, the display message
goes out. All driving systems/driving safety systems are operative again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 181).
X Switch off the engine.
X Clean the sensors (Y page 328) in the following locations:
R in the radiator trim
R in the front bumper
R in the rear bumper, particularly in the middle of the rear
bumper
X Restart the engine.
The display message disappears. ü If this symbol appears in the multifunction display, a seat belt
tongue has been inserted into a rear seat belt buckle.
Further information on the status indicator for the rear seat belts
(Y page 46). 260
Display
messagesOn-board computer and displays