2015 MERCEDES-BENZ B-Class ELECTRIC warning light

Display messages
Possible causes/consequences and
M
MSolutions The yellow
!warning lamp lights up. The red F(USA
only)/ !(Canada only) 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.
X Switch off the ignition and turn it back on.
X Apply the electric parking brake.
If it is not possible to engage the electric parking brake:
X Shift the selector lever to position P.
X Visit a qualified specialist workshop.
If it is not possible to release the electric parking brake manually:
X Release the electric parking brake automatically (Y page 155).
If the electric parking brake still cannot be released: X Consult a qualified specialist workshop. The yellow
!warning lamp lights up. If you manually apply or
release the electric parking brake, the red F(USA only)/ !
(Canada only) indicator lamp flashes.
The electric parking brake is malfunctioning. It is not possible to
apply the electric parking brake manually.
X Shift the selector lever to P, as the electric parking brake is not
applied automatically.
X Visit a qualified specialist workshop. Display
messages
207On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions F(USA
only)!
(Canada
only)
Parking Parking Brake
BrakeInop‐
Inop‐
erative
erative The yellow
!warning lamp lights up. The red F(USA
only)/ !(Canada only) 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 drive system.
X Engage or release the electric parking brake.
If it remains impossible to apply or release the electric parking
brake:
X Switch off the ignition and turn it back on.
X Engage or release the electric parking brake.
If the electric parking brake still cannot be released:
X Consult a qualified specialist workshop.
If the electric parking brake still cannot be applied:
X Visit a qualified specialist workshop. The yellow
!warning lamp lights up and the red F(USA
only)/ !(Canada only) indicator lamp flashes.
It is not possible to apply the electric parking brake manually.
X Shift the selector lever to position P.
X Visit a qualified specialist workshop. $(USA
only)J
(Canada
only)
Check Brake Fluid Check Brake Fluid
Level Level There is not enough brake fluid in the brake fluid reservoir.
A warning tone sounds. The
$(USA only)/ J(Canada only)
warning lamps in the instrument cluster may also light up.
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 153).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. 208
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Radar Sensors
Radar Sensors
Dirty See Opera‐ Dirty See Opera‐
tor's Manual tor's Manual COLLISION PREVENTION ASSIST PLUS is temporarily restricted or
inoperative.
Possible causes are:
R the sensors in the radiator trim and/or in the bumpers are dirty.
R the function of COLLISION PREVENTION ASSIST PLUS is
impaired due to heavy rain or snow.
A warning tone also sounds.
When the causes stated above no longer apply, the display mes-
sage disappears. COLLISION PREVENTION ASSIST PLUS is opera- tional 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 153).
X Switch off the drive system.
X Clean the sensors in the following locations (Y page 275):
R in the radiator trim
R in the front bumper
R in the rear bumper, particularly in the middle of the rear
bumper
X Start the drive system again.
The display message disappears. 6
SRS Malfunction SRS Malfunction
Service Required Service Required The restraint system is faulty. The
6warning lamp also lights
up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop.
For further information about the restraint system, see
(Y page 40). 210
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions 6
Front Front
Left
LeftMalfunc‐
Malfunc‐
tion Service
tion Service
Required Required orFront
Front
Right Malfunction
Right Malfunction
Service Required Service Required The restraint system has malfunctioned at the front on the left or
right. The 6warning lamp also lights up in the instrument clus-
ter.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 6
Rear Left Malfunc‐ Rear Left Malfunc‐
tion Service tion Service
Required Required
orRear
Rear
Right Malfunction
Right Malfunction
Service Required Service Required The rear left-hand or right-hand restraint system has malfunc-
tioned. The 6warning lamp also lights up in the instrument
cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 6
Rear Center Mal‐ Rear Center Mal‐
function Service function Service
Required Required The rear center restraint system has malfunctioned. The
6
warning lamp also lights up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 6
Left Side Curtain Left Side Curtain
Airbag Airbag
Malfunction
Malfunction
Service Required
Service Required
or Right Side Cur‐ Right Side Cur‐
tain Airbag Mal‐
tain Airbag Mal‐
function Service function Service
Required Required There is a malfunction in the left-hand or right-hand window cur-
tain air bag. The
6warning lamp also lights up in the instrument
cluster.
G WARNING
The left or right window curtain air bag may either be triggered
unintentionally or, in the event of an accident, may not be trig-
gered.
There is an increased risk of injury. X Visit a qualified specialist workshop. Display
messages
211On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Front Passenger
Front Passenger
Airbag Disabled Airbag Disabled
See See
Operator's
Operator's Man‐
Man‐
ual
ual The front-passenger air bag is deactivated during the journey, even
though:
R an adult
or
R a person of the corresponding stature is on the front-passenger
seat
If additional forces are applied to the seat, the system may inter-
pret the occupant's weight as lower than it actually is.
G WARNING
The front-passenger air bag does not deploy during an accident.
There is an increased risk of injury. 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 153).
X Switch the ignition off.
X Have the occupant get out of the vehicle.
X Keep the seat unoccupied, close the front-passenger door and
switch on the ignition.
X Observe the PASSENGER AIR BAG indicator lamps in the center
console and the multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the PASSENGER AIR BAG OFF and PASSENGER AIR BAG ON
indicator lamps must light up simultaneously for approx-
imately six seconds
R the PASSENGER AIR BAG OFF indicator lamp must then light
up and remain lit. If the indicator lamp is on, OCS has disabled
the front-passenger front air bag (Y page 49)
R the Front Front Passenger
Passenger Airbag
AirbagEnabled
Enabled See
SeeOperator's
Operator's
Manual
Manual orFront
Front Passenger
Passenger Airbag
AirbagDisabled
Disabled See
SeeOper‐
Oper‐
ator's Manual
ator's Manual display messages must not be shown in the
multifunction display.
X Wait for a period of at least 60 seconds until the necessary sys-
tem checks have been completed.
X Make sure that the display messages do not appear in the mul-
tifunction display.
If these conditions are fulfilled, the front-passenger seat can be
occupied again. Whether the PASSENGER AIR BAG OFF or ON
indicator lamp remains lit or goes out depends on how OCS clas- sifies the occupant.
If the conditions are not fulfilled, the system is not operating cor-
rectly. 212
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions X
Visit a qualified specialist workshop immediately.
For further information about the Occupant Classification System, see (Y page 49). Front Passenger
Front Passenger
Airbag Airbag
Enabled
Enabled See
See
Operator's Manual
Operator's Manual The front-passenger air bag is enabled during the journey, even
though:
R a child, a small adult or an object weighing less than the sys-
tem's weight threshold is located on the front-passenger seat
or
R the front-passenger seat is unoccupied
The system may detect objects or forces applying additional
weight on the seat.
G WARNING
The air bag may deploy unintentionally.
There is an increased risk of injury. 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 153).
X Switch the ignition off.
X Open the front-passenger door.
X Remove the child and the child restraint system from the front-
passenger seat.
X Make sure that there are no objects on the seat adding to the
weight.
The system may otherwise detect the additional weight and
interpret the seat occupant's weight as greater than it actually
is.
X Keep the seat unoccupied, close the front-passenger door and
switch on the ignition.
X Observe the PASSENGER AIR BAG indicator lamps in the center
console and the multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the PASSENGER AIR BAG OFF and PASSENGER AIR BAG ON
indicator lamps must light up simultaneously for approx-
imately six seconds
R the PASSENGER AIR BAG OFF indicator lamp must then light
up and remain lit. If the indicator lamp is on, OCS (Occupant
Classification System) has disabled the front-passenger front air bag (Y page 49)
R the Front Front Passenger
Passenger Airbag
AirbagEnabled
Enabled See
SeeOperator's
Operator's
Manual
Manual orFront
Front Passenger
Passenger Airbag
AirbagDisabled
Disabled See
SeeOper‐
Oper‐ Display
messages
213On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions b
Active Headlamps Active Headlamps
Inoperative Inoperative The light sensor is defective.
X Visit a qualified specialist workshop. b
Switch Off Lights Switch Off Lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Turn the light switch to Ã.Drive system
Display messages
Possible causes/consequences and
M MSolutions +
Check Coolant See Check Coolant See
Operator's Manual Operator's Manual The coolant level is too low.
! Avoid making long journeys with too little coolant in the cooling
system. The drive system will otherwise be damaged.
X If the coolant needs topping up more often than usual, have the
cooling system checked at a qualified specialist workshop. #
See See
Operator's
Operator's Man‐
Man‐
ual
ual The 12 V battery is no longer being charged.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the drive system.
X Secure the vehicle against rolling away (Y page 153).
X Do not drive on.
X Do not tow the vehicle.
X Consult a qualified specialist workshop. #
Stop Vehicle See Stop Vehicle See
Operator's Manual Operator's Manual The 12 V battery is no longer being charged and the battery charge
level is too low.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the drive system.
X Secure the vehicle against rolling away (Y page 153).
X Do not drive on.
X Do not tow the vehicle.
X Consult a qualified specialist workshop. Display
messages
217On-board computer and displays Z

Driving systems
Display messages
Possible causes/consequences and
M
MSolutions À
Attention Assist: Attention Assist:
Take a Break! Take a Break! Based on certain criteria, ATTENTION ASSIST has detected fatigue
or a lack of concentration on the part of the driver. A warning tone also sounds.
X If necessary, take a break.
During long journeys, take regular breaks in good time so you get enough rest. À
Attention Assist Attention Assist
Inoperative Inoperative ATTENTION ASSIST is inoperative.
X Visit a qualified specialist workshop. ë
Off Off The HOLD function is deactivated. The vehicle is skidding.
A warning tone also sounds.
X Reactivate the HOLD function later (Y page 163). The HOLD function is deactivated. When the brake pedal is firmly
depressed, an activation condition is not fulfilled.
A warning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 163). Blind Spot Assist Blind Spot Assist
Currently Unavail‐ Currently Unavail‐
able See Opera‐ able See Opera‐
tor's Manual tor's Manual Blind Spot Assist is temporarily inoperative. Possible causes are:
R function is impaired due to heavy rain or snow.
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 radar sensor system is outside the operating temperature
range.
The yellow 9indicator lamps also light up in the exterior mir-
rors.
When the causes stated above no longer apply, the display mes-
sage disappears.
Blind Spot Assist 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 153).
X Start the drive system again. Display
messages
219On-board computer and displays Z