
Display messages
Possible causes/consequences and
M
MSolutions front-passenger front airbag deactivation system has disa-
bled the front-passenger front airbag (Y
page 52)
R the Front-passenger airbag enabled See Owner's Front-passenger airbag enabled See Owner's
Manual
Manual orFront-passenger
Front-passenger airbag
airbagdisabled
disabled See
SeeOwn‐
Own‐
er's Manual
er's Manual display messages must not appear in the mul-
tifunction 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 met, the front-passenger seat can be occu-
pied again. Whether the PASSENGER AIRBAG OFF or ON indicator
lamp remains lit or goes out depends on how the automatic front-
passenger front airbag deactivation system classifies the occu-
pant.
If the conditions are not met, the system is not operating correctly.
X Consult a qualified specialist workshop immediately.
Further information on the automatic front-passenger front airbag deactivation feature (Y page 51).Lights
i Vehicles with LED light bulbs in the light clusters:
The display message for the corresponding lamp only appears when all of 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 Consult a qualified specialist workshop. b
Left dipped beam Left dipped beam
or
Right dipped Right dipped
beam beam The left or right-hand dipped-beam headlamp is faulty.
X Consult a qualified specialist workshop. b
Rear left indica‐ Rear left indica‐
tor tor
orRear right
Rear right
indicator
indicator The rear left-hand or rear right-hand turn signal is faulty.
X Consult a qualified specialist workshop. 280
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions b
Reversing light Reversing light The left or right-hand reversing lamp is faulty.
X Consult a qualified specialist workshop. b
Left daytime driv‐ Left daytime driv‐
ing lamp ing lamp
orRight
Right
daytime driving
daytime driving
lamp lamp The left or right-hand daytime driving lamp is faulty.
X Consult a qualified specialist workshop. b
Active Light Sys‐ Active Light Sys‐
tem inoperative tem inoperative The active light function 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
without the Intelligent Light System.
X Consult a qualified specialist workshop. b
Malfunction See Malfunction See
Owner's Manual Owner's Manual The exterior lighting is faulty.
X Consult a qualified specialist workshop. b
AUTO AUTO
lights
lights inoper‐
inoper‐
ative
ative The light sensor is faulty.
X Consult a qualified specialist workshop. b
Switch off lights Switch off lights You are leaving the vehicle and the lights are still switched on. A
warning tone also sounds.
X Turn the light switch to position Ã.b
Switch Switch
on
onheadlamps
headlamps You are driving without dipped-beam headlamps.
X
Turn the light switch to position LorÃ. 282
Display
messagesOn-board computer and displays

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 to prevent it from rolling away (Y page 181).
X Insert the key into the ignition lock and bring into key mode. Â
Remove starting Remove starting
button, then button, then
insert key insert key The key is continually undetected.
The key detection function has a temporary malfunction or is
faulty. A warning tone also sounds.
X Insert the key into the ignition lock and turn it to the desired
position.
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
General notes
Some systems carry out a self-diagnosis when the ignition is switched on. Several warning and indicator lamps can thereby temporarily light up or flash. This behaviour is non-critical. These
warning and indicator lamps only indicate a malfunction if they light up or flash after the engine is started or during a journey. Safety
Seat belts Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ü
N
Only for certain countries: the red seat belt warning lamp lights up for
6 seconds after the engine starts.
The seat belt warning lamp reminds the driver and front passenger to fasten
their seat belts.
X Fasten your seat belt (Y page 46).ü
N
Only for certain countries: the red seat belt warning lamp lights up after the
engine 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 46).
The warning tone ceases. 302
Wa
rning and indi cator lamps in the instrument clusterOn-board computer and displays

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 passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 46).
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 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 46).
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. Warning and indicator lamps in the instrument cluster
303On-board computer and displays Z

Safety systems
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions J
N
The yellow brake system warning lamp lights up while the engine is running.
G WARNING
The brake system is malfunctioning and the braking characteristics may be
affected.
There is a risk of an accident. X If the multifunction display shows a display message, please observe this.
X Drive on carefully.
X Consult a qualified specialist workshop. J
N
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 Safeguard the vehicle against rolling away (Y page 181).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. J
N
The red brake system warning lamp is lit while the engine is running.
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 circumstan-
ces.
X Safeguard the vehicle against rolling away (Y page 181).
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 display. 304
Warning and indicator lamps in the instrument clusterOn-board computer and displays

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) has been deactivated due to a fault. Therefore BAS (Brake Assist), BAS PLUS with Cross-Traffic Assist, COLLISION PREVEN-
TION ASSIST PLUS, ESP ®
(Electronic Stability Program), PRE‑SAFE ®
,
PRE‑ SAFE ®
PLUS, PRE‑ SAFE®
Brake, the HOLD function, Hill Start Assist,
Crosswind Assist, adaptive brake lights, STEER CONTROL, Active Lane Keep- ing 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 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 display.
X Drive on carefully.
X Consult 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 be unavail- able. Warning and indicator lamps in the instrument cluster
305On-board computer and displays Z

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 unavailable 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, adaptive brake lights, 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, 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 display.
X Drive on carefully.
X Consult a qualified specialist workshop. 306
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions J÷
!
N
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 unavailable due to a fault. 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, adaptive brake lights, 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, 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 display.
X Drive on carefully.
X Consult 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 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 76) it may be best to deactivate ESP ®
.
Observe the important safety notes on ESP ®
(Y page 76). Warning and indicator lamps in the instrument cluster
307On-board computer and displays Z