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 191).
X Insert the key into the ignition lock and bring into key mode. Â
Remove Remove
starting
starting but‐
but‐
ton,
ton, then
theninsert
insert key
key R
The key detection function has a temporary malfunction or is faulty.
R The key is continually undetected.
A warning tone also sounds.
X Insert the key into the ignition lock and turn it to the desired posi-
tion.
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 47).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 47).
The warning tone ceases. Wa
rning and indi cator lamps in the instrument cluster
337On-board computer and displays Z
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions 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 47).
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 47).
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. 338
Warning and indicator lamps in the instrument clusterOn-board computer and displays
Safety systems
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions J
N
The red brake system warning lamp is lit while the engine is running.
PLUG-IN HYBRID vehicles:
The red brake system warning lamp is shown in the READY driving status.
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 circumstances.
X Safeguard the vehicle against rolling away (Y page 191).
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.
PLUG-IN HYBRID vehicles:
The red brake system warning lamp is shown in the READY driving status.
A warning tone also sounds.
G WARNING
There is insufficient brake fluid in the brake fluid reservoir.
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 191).
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. J
N
The yellow brake system warning lamp lights up while the engine is running.
PLUG-IN HYBRID vehicles:
The yellow brake system warning lamp is shown in the READY driving status.
A warning tone also sounds.
G WARNING
The brake system is malfunctioning and the braking characteristics may be affec- ted.
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 immediately. Warning and indicator lamps in the instrument cluster
339On-board computer and displays Z
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions J
N
The red brake system warning lamp is lit while the engine is running.
PLUG-IN HYBRID vehicles:
The red brake system warning lamp is shown in the READY driving status.
A warning tone also sounds.
G WARNING
RBS is malfunctioning. Pedal travel may be longer than usual and braking per-
formance 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 circumstances.
X Safeguard the vehicle against rolling away (Y page 191).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. J
N
The yellow brake system warning lamp lights up while the engine is running.
PLUG-IN HYBRID vehicles:
The yellow brake system warning lamp is shown in the READY driving status.
A warning tone also sounds.
G WARNING
RBS is malfunctioning. Pedal travel may be longer than usual and braking per-
formance 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 immediately. 340
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.
PLUG-IN HYBRID vehicles:
The yellow ABS warning lamp is shown in the READY driving status.
ABS (Anti-lock Braking System) has been deactivated due to a fault. BAS (Brake
Assist), BAS PLUS with Cross-Traffic Assist, COLLISION PREVENTION ASSIST
PLUS, ESP ®
(Electronic Stability Program), ESP ®
trailer stabilisation, EBD (Elec-
tronic Brake-force Distribution), PRE ‑SAFE®
, PRE‑ SAFE®
PLUS, PRE ‑SAFE®
Brake,
HOLD function, hill start assist, Crosswind Assist, adaptive brake lights, STEER
CONTROL, Active Lane Keeping Assist and Active Blind Spot Assist, for example,
are therefore also deactivated.
In addition, the ÷andå warning lamps may light up in the instrument
cluster.
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 immediately.
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 unavailable. Warning and indicator lamps in the instrument cluster
341On-board computer and displays Z
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions !
N
The yellow ABS warning lamp is lit while the engine is running.
PLUG-IN HYBRID vehicles:
The yellow ABS warning lamp is shown in the READY driving status.
ABS is temporarily unavailable. BAS, BAS PLUS with Cross-Traffic Assist, COLLI-
SION PREVENTION ASSIST PLUS, ESP ®
(Electronic Stability Program), ESP ®
trailer
stabilisation, EBD, PRE‑SAFE ®
, PRE‑ SAFE®
PLUS, PRE‑ SAFE®
Brake, HOLD func-
tion, hill start assist, Crosswind Assist, adaptive brake lights, STEER CONTROL,
Active Lane Keeping Assist and Active Blind Spot Assist, for example, are therefore
also deactivated.
In addition, the ÷andå warning lamps may light up in the instrument
cluster.
ATTENTION ASSIST is deactivated.
Possible causes:
R self-diagnosis is not yet complete
R the on-board voltage may be insufficient
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 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 warning lamp goes
out.
If the warning lamp is still on: X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Consult a qualified specialist workshop immediately. 342
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.
PLUG-IN HYBRID vehicles:
The yellow ABS warning lamp is shown in the READY driving status.
EBD is unavailable due to a malfunction. ABS, BAS, BAS PLUS with Cross-Traffic
Assist, COLLISION PREVENTION ASSIST PLUS, ESP ®
, ESP ®
trailer stabilisation,
PRE‑ SAFE ®
, PRE ‑SAFE ®
PLUS, PRE ‑SAFE®
Brake, HOLD function, hill start assist,
Crosswind Assist, adaptive brake lights, STEER CONTROL, Active Lane Keeping
Assist and Active Blind Spot Assist, for example, are therefore also deactivated.
In addition, the ÷andå warning lamps may light up in the instrument
cluster.
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 immediately. J÷
å!
N
The red brake system warning lamp and the yellow ESP ®
, ESP ®
OFF and ABS
warning lamps are lit while the engine is running.
PLUG-IN HYBRID vehicles:
ABS and ESP ®
are malfunctioning. BAS, BAS PLUS with Cross-Traffic Assist, COL-
LISION PREVENTION ASSIST PLUS, ESP ®
trailer stabilisation, PRE ‑SAFE®
,
PRE‑ SAFE ®
PLUS, PRE‑SAFE ®
Brake, HOLD function, hill start assist, Crosswind
Assist, adaptive brake lights, STEER CONTROL, Active Lane Keeping Assist and
Active Blind Spot Assist, for example, are therefore also deactivated.
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 immediately. Warning and indicator lamps in the instrument cluster
343On-board computer and displays Z
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ֌
N
The yellow ESP ®
and ESP ®
OFF warning lamps are lit while the engine is running.
PLUG-IN HYBRID vehicles:
The yellow ESP ®
and ESP ®
OFF warning lamps are lit in the READY driving status.
ESP ®
, BAS, BAS PLUS with Cross-Traffic Assist, COLLISION PREVENTION ASSIST
PLUS, ESP ®
trailer stabilisation, PRE‑SAFE ®
, PRE‑SAFE ®
PLUS, PRE‑SAFE ®
Brake,
HOLD function, hill start assist, Crosswind Assist, adaptive brake lights, STEER
CONTROL, Active Lane Keeping Assist and Active Blind Spot Assist, for example,
are unavailable due to a malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance may thus 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 immediately. Warning and indicator lamps in the instrument cluster
345On-board computer and displays Z