Page 357 of 502

Display messages
Possible causes/consequences and
M
MSolutions Because there is interference from a strong source of radio waves,
the key is not detected whilst the engine is running.
A warning tone also sounds.
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 220).
X Insert the SmartKey into the ignition lock and bring into key
mode. Â
Remove Remove
'Start'
'Start' But‐
But‐
ton and Insert Key
ton and Insert Key The SmartKey is continually undetected.
The SmartKey detection function has a temporary malfunction or
is faulty. A warning tone also sounds.
X Insert the SmartKey into the ignition lock and turn it to the
desired position.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
Safety
Seat belts Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ü
N
After starting the engine, the red seat belt warning lamp lights up for
6 seconds.
The seat belt warning lamp reminds the driver and front passenger to fasten
their seat belts.
X Fasten your seat belt (Y page 54).ü
N
After starting the engine, the red seat belt warning lamp lights up. In addi-
tion, a warning tone sounds for up to 6 seconds.
The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 54).
The warning tone ceases. Wa
rning and indi cator lamps in the instrument cluster
355On-board computer and displays Z
Page 358 of 502

Warning/
indicator
lamp
N
N Signal type
Possible causes/consequences and M MSolutions ü
N
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 54).
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
N
The red seat belt warning lamp flashes and an intermittent audible warning
sounds.
The driver or front passenger has not fastened their seat belt. The vehicle is
being driven faster than 15 mph (25 km/h) or has briefly been driven faster
than 15 mph (25 km/h).
X Fasten your seat belt (Y page 54).
The warning lamp goes out and the intermittent warning tone ceases.
There are objects on the front-passenger seat. The vehicle is being driven
faster than 15 mph (25 km/h) or has briefly been 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. 356
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Page 359 of 502

Safety systems
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions $J
N
$ (USA only), J(Canada only): the red brake system warning lamp
is lit while the engine is running. A warning tone also sounds.
G WARNING
The brake boosting effect is malfunctioning and the braking characteristics
may be affected.
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 circumstan-
ces.
X Secure the vehicle against rolling away (Y page 220).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. $J
N
$ (USA only), J(Canada only): the red brake system warning lamp
is lit 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 circumstan-
ces.
X Secure the vehicle against rolling away (Y page 220).
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. $
N
USA only: the red brake system warning lamp is lit while the engine is
running. The multifunction display also shows a display message with the
# symbol.
The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
357On-board computer and displays Z
Page 360 of 502

Warning/
indicator
lamp
N
N Signal type
Possible causes/consequences and M MSolutions !
N
The yellow ABS warning lamp is lit while the engine is running.
ABS (Anti-lock Braking System) is deactivated due to a malfunction. Therefore BAS (Brake Assist System), BAS PLUS with Cross-Traffic Assist, COLLISION
PREVENTION ASSIST PLUS, ESP ®
(Electronic Stability Program), PRE‑SAFE ®
,
PRE‑SAFE ®
PLUS, PRE‑SAFE ®
Brake, the HOLD function, hill start assist,
Crosswind Assist, STEER CONTROL, Active Lane Keeping Assist and Active
Blind Spot Assist are also deactivated.
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. 358
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Page 361 of 502

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions !
N
The yellow ABS warning lamp is lit while the engine is running. A warning
tone also sounds.
EBD is not available due to a malfunction. Therefore ABS, BAS, BAS PLUS with
Cross-Traffic Assist, COLLISION PREVENTION ASSIST PLUS, ESP ®
,
PRE‑SAFE ®
, PRE‑SAFE ®
PLUS, PRE‑SAFE ®
Brake, the HOLD function, hill start
assist, Crosswind Assist, STEER CONTROL, Active Lane Keeping Assist and
Active Blind Spot Assist are also unavailable.
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
359On-board computer and displays Z
Page 362 of 502

Warning/
indicator
lamp
N
N Signal type
Possible causes/consequences and M MSolutions $J
÷!
N
$ (USA only), J(Canada only): the red brake warning lamp, the
yellow ESP ®
warning lamp and the yellow ABS warning lamp are lit while the
engine is running.
ABS and ESP ®
are not available due to a malfunction. Therefore BAS, BAS
PLUS with Cross-Traffic Assist, COLLISION PREVENTION ASSIST PLUS, EBD,
PRE‑SAFE ®
, PRE‑SAFE ®
PLUS, PRE‑SAFE ®
Brake, the HOLD function, hill start
assist, Crosswind Assist, STEER CONTROL, Active Lane Keeping Assist and
Active Blind Spot Assist are also unavailable.
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. ÷
N
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 ®
.
In rare cases (Y page 82), it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 82). 360
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Page 363 of 502

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ÷
N
The yellow ESP ®
warning lamp is lit while the engine is running.
ESP ®
, BAS, BAS PLUS with Cross-Traffic Assist, COLLISION PREVENTION
ASSIST PLUS, PRE ‑SAFE®
, PRE‑SAFE ®
PLUS, PRE‑SAFE ®
Brake, the HOLD
function, hill start assist, Crosswind Assist, STEER CONTROL, Active Lane
Keeping Assist and Active Blind Spot Assist are unavailable due to a malfunc-
tion.
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. å
N
The yellow ESP ®
OFF warning lamp is lit while the engine is running.
ESP ®
is deactivated.
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 ®
.
In rare cases (Y page 82), it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 82).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Drive on carefully.
X Have ESP ®
checked at a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
361On-board computer and displays Z
Page 364 of 502
Warning/
indicator
lamp
N
N Signal type
Possible causes/consequences and M MSolutions F!
N
F (USA only), !(Canada only): the red indicator lamp for the electric
parking brake flashes or is lit and/or the yellow warning lamp for the electric parking brake is lit.
X Observe the additional display messages in the multifunction display. 6
N
The red restraint system warning lamp is lit while the engine is running.
The restraint system is faulty.
G WARNING
The air bags or Emergency Tensioning Devices may either be triggered unin-
tentionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury. X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Have the restraint system checked at a qualified specialist workshop imme-
diately.
For further information about the restraint system, see (Y page 49).362
Warning and indicator lamps in the instrument clusterOn-board computer and displays