2015 MERCEDES-BENZ B-CLASS HATCHBACK light

Display messages
Possible causes/consequences and
M
MSolutions Front-passenger
Front-passenger
airbag enabled See airbag enabled See
Owner's Manual Owner's Manual The front-passenger front airbag is enabled during the journey
although:
R a child, a small adult or an object weighing less than the system
weight threshold is located on the front-passenger seat
or
R the front-passenger seat is not occupied
The system may detect objects or forces that are adding to the weight
applied to the seat.
G WARNING
The airbag may deploy unintentionally.
This poses 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 Safeguard the vehicle against rolling away (Y page 145).
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 there are no objects applying additional force to the seat.
The system may otherwise detect the additional force and interpret the seat occupant's weight as greater than it actually is.
X Make sure that the seat is unoccupied, close the front-passenger
door and switch on the ignition.
X Observe the PASSENGER AIR BAG indicator lamps in the centre
console and the multifunction display and check the following:
Seat unoccupied and ignition switched on:
R a self-diagnosis takes place. The PASSENGER AIR BAG OFF and
PASSENGER AIR BAG ON indicator lamps light up simultaneously
for approximately six seconds
R the PASSENGER AIR BAG OFF indicator lamp must light up and
remain on after the self-diagnosis. If the indicator lamp is on, the
automatic front-passenger front airbag deactivation system has
disabled the front-passenger front airbag (Y page 42)
R the Front-passenger
Front-passenger airbag airbagenabled
enabled See
SeeOwner's
Owner's Manual
Manual
or Front-passenger
Front-passenger airbag
airbagdisabled
disabled See
SeeOwner's
Owner's Manual
Manual
display messages must not be shown in the multifunction display
X Wait for a period of at least 60 seconds until the necessary system
checks have been completed.
X Make sure that the display messages do not appear in the multi-
function display.
If these conditions are met, 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 the automatic front-passenger front airbag deactivation system classifies the occupant.
If the conditions are not met, the system is not operating correctly.
X Consult a qualified specialist workshop immediately. 200
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Further information on the automatic front-passenger front airbag
deactivation feature (Y page 42).Lights
i Vehicles with LED light bulbs in the light clusters:
The display message for the corresponding lamp only appears when all the LEDs in the lamp have
failed. Display messages
Possible causes/consequences and
M
MSolutions b
Left cornering Left cornering
light light
orRight cor‐
Right cor‐
nering light
nering light The left or right-hand cornering light is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 103).
or
X Consult a qualified specialist workshop. b
Left dipped beam Left dipped beam
or
Right dipped beam
Right dipped beam The left or right-hand dipped-beam headlamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 103).
or
X Consult a qualified specialist workshop. b
Rear Rear
left
leftindicator
indicator
or Rear right indi‐
Rear right indi‐
cator
cator The rear left-hand or rear right-hand turn signal is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 103).
or
X Consult a qualified specialist workshop. b
Front left indica‐ Front left indica‐
tor tor
orFront right
Front right
indicator
indicator The front left-hand or front right-hand turn signal is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 103).
or
X Consult a qualified specialist workshop. b
Left mirror indica‐ Left mirror indica‐
tor tor
orRight mirror
Right mirror
indicator
indicator The turn signal in the left-hand or right-hand exterior mirror is faulty.
X Consult a qualified specialist workshop. b
Third brake lamp Third brake lamp The third brake lamp is faulty.
X Consult a qualified specialist workshop. b
Left brake Left brake
lamp lampor
Right brake
Right brake
lamp
lamp The left or right-hand brake lamp is faulty.
X Consult a qualified specialist workshop. Display
messages
201On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions b
Left main beam Left main beam
or
Right main beam
Right main beam The left or right-hand main-beam headlamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 103).
or X Consult a qualified specialist workshop. b
Number plate lamp Number plate lamp The left or right-hand licence plate lamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 103).
or
X Consult a qualified specialist workshop. b
Rear foglamp Rear foglamp The rear foglamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 103).
or X Consult a qualified specialist workshop. b
Front left parking Front left parking
lamp lamp
orFront right
Front right
parking lamp
parking lamp The front left or front right parking lamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 103).
or X Consult a qualified specialist workshop. b
Reversing light Reversing light The reversing lamp is faulty.
X Check whether you are permitted to replace the bulb yourself
(Y page 103).
or
X Consult a qualified specialist workshop. b
Left tail lamp Left tail lamp
or
Right tail lamp
Right tail lamp The left or right-hand tail lamp is faulty.
X Consult a qualified specialist workshop. b
Left daytime driv‐ Left daytime driv‐
ing lamp ing lamp
orRight
Right
daytime
daytime driving
drivinglamp
lamp The left or right-hand daytime driving lamp is faulty.
X Consult a qualified specialist workshop. b
Intell. Light Sys‐ Intell. Light Sys‐
tem inoperative tem inoperative The Intelligent Light System is faulty. The lights remain available with-
out the Intelligent Light System.
X Consult a qualified specialist workshop. b
Malfunction Malfunction
See
SeeOwn‐
Own‐
er's Manual
er's Manual The exterior lighting is faulty.
X Consult a qualified specialist workshop. 202
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions b
AUTO lights inoper‐ AUTO lights inoper‐
ative ative The light sensor is faulty.
X
Consult 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 the Ãposition. b
Switch on headlamps Switch on headlamps You are driving without dipped-beam headlamps.
X
Turn the light switch to the Lorà position. Adaptive Main-beam Adaptive Main-beam
Assist currently Assist currently
unavailable unavailable
See
SeeOwn‐
Own‐
er's Manual
er's Manual Adaptive Highbeam Assist is deactivated and temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
X Clean the windscreen.
If the system detects that the camera is fully operational again, the Adaptive Main-beam Assist available again
Adaptive Main-beam Assist available again message is dis-
played.
Adaptive Highbeam Assist is operational again. Adaptive Main-beam Adaptive Main-beam
Assist inoperative Assist inoperative Adaptive Highbeam Assist is faulty.
X
Consult a qualified specialist workshop. Display
messages
203On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Lane
Lane
Keeping
Keeping Assist
Assist
currently unavaila‐
currently unavaila‐
ble ble See
SeeOwner's
Owner's Man‐
Man‐
ual
ual Lane Keeping Assist is deactivated and temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision
R visibility is impaired due to heavy rain, snow or fog
R there have been no lane markings for an extended period
R the lane markings are worn, dark or covered, e.g. by dirt or snow
Once the causes listed above no longer apply, the display message
goes out.
Lane Keeping 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 Safeguard the vehicle against rolling away (Y page 145).
X Clean the windscreen. Lane Lane
Keeping
Keeping Assist
Assist
inoperative
inoperative Lane Keeping Assist is faulty.
X Consult a qualified specialist workshop. Blind Spot Assist
Blind Spot Assist
currently unavaila‐ currently unavaila‐
ble ble
See
SeeOwner's
Owner's Man‐
Man‐
ual
ual Blind Spot Assist is temporarily inoperative.
Possible causes:
R the radar sensor system is temporarily inoperative, e.g. due to elec-
tromagnetic radiation emitted by nearby TV or radio stations 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 mirrors.
Once the causes listed above no longer apply, the display message
goes out.
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 Safeguard the vehicle against rolling away (Y page 145).
X Start the drive system again. Blind Spot Assist Blind Spot Assist
inoperative inoperative Blind Spot Assist is faulty.
The yellow
9indicator lamps also light up in the exterior mirrors.
X Consult a qualified specialist workshop. Park Assist cancel‐ Park Assist cancel‐
led led The driver's door is open and the driver's seat belt has not been fas-
tened.
X Repeat the parking process with the seat belt fastened and the
driver's door closed. 206
Display
messagesOn-board computer and displays

Safety
Seat belts Problem
Possible causes/consequences and
M
MSolutions ü
Only for certain coun-
tries: the red seat belt
warning lamp lights up
for 6 seconds after the
drive system starts.
The seat belt warning lamp reminds the driver and front passenger to
fasten their seat belts.
X Fasten your seat belt (Y page 37).ü
Only for certain coun-
tries: the red seat belt
warning lamp lights up
after the drive system
starts. In addition, a
warning tone sounds for
up to 6 seconds.
The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 37).
The warning tone ceases. ü
The red seat belt warning
lamp lights up after the
drive system starts, as
soon as the driver's or
the front-passenger door is closed. The driver or passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 37).
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 passenger has not fastened their seat belt. At the same
time, you are driving faster than 25 km/h or have briefly driven faster
than 25 km/h.
X Fasten your seat belt (Y page 37).
The warning lamp goes out and the intermittent warning tone
ceases. There are objects on the front-passenger seat. At the same time, you
are driving faster than 25 km/h or have briefly driven faster than
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. 214
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions J
The red brake system
warning lamp is lit while
the drive system is run-
ning. A warning tone also
sounds. There is insufficient brake fluid in the brake fluid reservoir.
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 Safeguard the vehicle against rolling away (Y page 145).
X Do not top up the brake fluid. Topping up will not rectify the fault.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction dis-
play. !֌J
The yellow ABS, ESP
®
,
ESP ®
OFF and brakes
warning lamps are lit
while the drive system is running. ABS (Anti-lock Braking System) has been deactivated due to a fault.
Therefore, BAS (Brake Assist), COLLISION PREVENTION ASSIST
PLUS, ESP ®
(Electronic Stability Program), RBS, PRE ‑SAFE®
, the
HOLD function, hill start assist and the adaptive brake lights, for
example, are also deactivated.
ATTENTION ASSIST is deactivated.
G WARNING
The braking performance of the electric motor using recuperative
braking may be either reduced or not effective. If you do not make an
additional effort to apply the brake yourself, the braking effect may not be sufficient. If necessary, counteract the reduced regenerative brak-
ing effect by applying the brake yourself.
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 may increase in an emergency braking situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction dis-
play.
X Drive on carefully.
X Consult a qualified specialist workshop immediately.
If the ABS control unit is malfunctioning, other systems may also not
be available, e.g. the navigation system. 216
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions !֌J
The yellow ABS, ESP
®
,
ESP ®
OFF and brakes
warning lamps are lit
while the drive system is running. ABS is temporarily unavailable. Therefore, BAS, RBS, COLLISION PRE-
VENTION ASSIST PLUS, ESP ®
, EBD (electronic brake force distribu-
tion), PRE‑SAFE ®
, the HOLD function, hill start assist and the adaptive
brake lights, for example, are also deactivated.
Possible causes:
R Self-diagnosis is not yet complete
R The on-board voltage may be insufficient.
ATTENTION ASSIST is deactivated.
G WARNING
The braking performance of the electric motor using recuperative
braking may be either reduced or not effective. If you do not make an
additional effort to apply the brake yourself, the braking effect may not be sufficient. If necessary, counteract the reduced regenerative brak-
ing effect by applying the brake yourself.
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore lock, for example, if you brake hard.
The steerability and braking characteristics may be severely affected.The braking distance may increase in an emergency braking situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise 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 20 km/h.
The functions mentioned above are available again when the warn-
ing lamp goes out.
If the warning lamp is still on: X Observe the additional display messages in the multifunction dis-
play.
X Drive on carefully.
X Consult a qualified specialist workshop immediately. Warning and indicator lamps in the instrument cluster
217On-board computer and displays Z