2015 MERCEDES-BENZ B-CLASS HATCHBACK warning

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

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. EBD is faulty. Therefore, ABS, BAS, COLLISION PREVENTION ASSIST
PLUS, ESP ®
, RBS, PRE ‑SAFE®
, the HOLD function, hill start assist and
the adaptive brake lights, for example, are not available either.
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 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. !֌J
The red brake system
warning lamp and the
yellow ABS, ESP
®
and
ESP ®
OFF warning lamps
are lit while the drive sys-
tem is running. ABS and ESP
®
are malfunctioning. Therefore, BAS, RBS, COLLISION
PREVENTION ASSIST PLUS, EBD, PRE ‑SAFE®
, the HOLD function, hill-
start assist and the adaptive brake lights, for example, are not avail-
able either.
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 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. 218
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions ÷
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 is deactivated.
X Only depress the accelerator pedal as far as necessary when pulling
away.
X Accelerate more gently while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
In rare cases (Y page 66) it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 65). å
The yellow ESP
®
OFF
warning lamp is lit while
the drive system is run-
ning. ESP
®
is deactivated. ESP ®
will not stabilise the vehicle if it starts to
skid or if a wheel starts to spin.
G WARNING
If ESP ®
is deactivated, ESP ®
is unable to stabilise the vehicle.
Further driving systems or driving safety systems are thus restricted. There is an increased danger of skidding and risk of an accident.
X Reactivate ESP ®
.
In rare cases (Y page 66) it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 65).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Drive on carefully.
X Contact a qualified specialist workshop and have ESP ®
checked. Warning and indicator lamps in the instrument cluster
219On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions ֌J
The yellow ESP
®
, ESP ®
OFF and brakes warning
lamps are lit while the
drive system is running. ESP
®
, RBS, BAS, COLLISION PREVENTION ASSIST PLUS, PRE‑SAFE ®
,
the HOLD function, hill start assist and the adaptive brake lights are
not available due to a malfunction.
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 braking distance may thus increase in an emergency braking sit-
uation.
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. 220
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions ֌J
The yellow ESP
®
, ESP ®
OFF and brakes warning
lamps are lit while the
drive system is running. ESP
®
, BAS, PRE‑SAFE ®
, the HOLD function and hill start assist are
temporarily unavailable.
The adaptive brake lights and COLLISION PREVENTION ASSIST PLUS
may also have failed.
ATTENTION ASSIST is deactivated.
Self-diagnosis is not yet complete
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 braking distance may thus increase in an emergency braking sit-
uation.
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 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
221On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions !
The red indicator lamp
for the electric parking
brake flashes or is lit
and/or the yellow warn-
ing lamp for the electric
parking brake is lit. X
Observe the additional display messages in the multifunction dis-
play. 6
The red restraint system
warning lamp is lit while
the drive system is run-
ning.
The restraint system is faulty.
G WARNING
The airbags or belt tensioners may either be triggered unintentionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury.
X Observe the additional display messages in the multifunction dis-
play.
X Drive on carefully.
X Contact a qualified specialist workshop and have the restraint sys-
tem checked.
For further information about the restraint system, see (Y page 34).Drive system
Problem
Possible causes/consequences and
M MSolutions Ý
The yellow battery
charge warning lamp is
on.
The charge level of the high-voltage battery has dropped into the
reserve range.
X
Charge the high-voltage battery. Driving systems
Problem
Possible causes/consequences and
M MSolutions ·
The red distance warning
lamp lights up while the
vehicle is in motion. The distance to the vehicle in front is too small for the speed selected.
X Increase the distance. ·
The red distance warning
lamp lights up while the
vehicle is in motion. A
warning tone also
sounds. You are approaching a vehicle or a stationary obstacle in your line of
travel at too high a speed.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to brake
or take evasive action.
For further information on the distance warning function of COLLI-
SION PREVENTION ASSIST PLUS, see (Y page 62).222
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Tyres
Problem
Possible causes/consequences and
M
MSolutions h
The yellow tyre pressure
monitor warning lamp
(pressure loss/malfunc-
tion) is lit.
The tyre pressure monitor has detected a loss of pressure in at least
one of the tyres.
G WARNING
Underinflated tyres pose the following risks:
R the tyres may burst, especially as the load and vehicle speed
increase
R the tyres may wear excessively and/or unevenly, which may greatly
impair tyre traction
R the driving characteristics, as well as steering and braking, may be
greatly impaired
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away (Y page 145).
X Observe the additional display messages in the multifunction dis-
play.
X Check the tyres and, if necessary, follow the instructions for a flat
tyre (Y page 249).
X Check the tyre pressure (Y page 270).
X If necessary, correct the tyre pressure. h
The yellow tyre pressure
monitor warning lamp
(pressure loss/malfunc-
tion) flashes for approx-
imately one minute and
then remains lit.
The tyre pressure monitor is faulty.
G WARNING
The system is possibly unable to detect or register low tyre pressure.
There is a risk of an accident.
X Observe the additional display messages in the multifunction dis-
play.
X Consult a qualified specialist workshop immediately. Warning and indicator lamps in the instrument cluster
223On-board computer and displays Z