
Display messages Possible causes/consequences and
M Solutions
PRE-SAFE
Functions
Currently Limited
See Operator's
Manual Adaptive Brake Assis
tis temporarily inoperative. Possible causes
are:
R the radar sensor system cover in the radiator grill is dirty.
R function is impaired due to heavy rain or snow.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio
stations or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
When the causes stated above no longer apply, the display
message disappears.
Adaptive Brake 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 Secure the vehicle against rolling away (Y page 141).
X Cleant he radar sensor cover in the radiator grill (Y page 269).
X Restart the engine. PRE-SAFE
Functions Limited
See Operator's
Manual Adaptive Brake Assist is faulty. The distance warning signal may
also have failed.
X
Visit a qualified specialist workshop. 6
SRS Malfunction
Service Required There is a malfunction in the SRS (Supplemental Restraint
System). The
6warning lamp also lights up in the instrument
cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop.
Further information on occupant safety (Y page 36). Display messages
201On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
6
Front Left
Malfunction
Service Required
or
Front Right Malfunction
Service Required SRS has malfunctioned at the front on the left or right. The
6
warning lamp also lights up in the instrumen tcluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 6
Rear Left
Malfunction
Service Required
or
Rear Right Malfunction
Service Required SRS has malfunctioneda
t the rear on the left or right. The 6
warning lamp also lights up in the instrument cluster.
G WARNING
The ai rbags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased ris kofinjury.
X Visi taqualified specialist workshop. 6
Rear Center
Malfunction
Service Required SRS has malfunctioned at the rear center. The
6warning lamp
also lights up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 6
Left Side Curtain
Airbag Malfunction
Service Required
or
Right Side Curtain Airbag
Service Required There is a malfunction in the left-hand or right-hand window
curtain air bag. The
6warning lamp also lights up in the
instrument cluster.
G WARNING
The left or right window curtain air bag may either be triggered
unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. Lights
i Display messages about LEDs: 202
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
Wiper
Malfunctioning The windshield wipers are malfunctioning.
X
Visit a qualified specialist workshop. Hazard Warning
Flashers
Malfunctioning The hazard warning lamps are faulty.
X
Visit a qualified specialist workshop. SmartKey
Display messages Possible causes/consequences and
M Solutions
+
Key Does Not
Belong to Vehicle You have put the wrong SmartKey in the ignition lock.
X
Use the correct SmartKey. +
Take
Your Key from
Ignition The SmartKey is in the ignition lock.
X
Remove the SmartKey. +
Obtain a New Key The SmartKey needs to be replaced.
X
Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
Sea
tbelts Problem Possible causes/consequences and
M Solutions
ü
After starting the
engine, the red seat
belt warning lamp lights
up for six seconds.
The seat belt warning lamp reminds the driver and fron
tpassenger
to fasten their seat belts.
X Faste nyour seat belt (Y page 43). ü
After starting the
engine, the red seat
belt warning lamp lights
up. In addition, a
warning tone sounds
for up to six seconds.
The driver's seat belt is not fastened.
X
Fasten your seat belt (Y page 43).
The warning tone ceases. 218
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
ü
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 43).
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 front passenger has not fastened their seat belt. In
addition, you are driving faster than 15 mph (25 km/h)
or you have
briefly driven faster than 15 mph (25 km/h).
X Fasten your seat belt (Y page 43).
The warning lamp goes out and the intermittentw arning tone
ceases. There are objects on th
efront-passenge rseat. In addition, you are
driving faster than 15 mph (25 km/h) or you have briefly 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 intermittentw arning tone
ceases. Warning and indicator lamps in the instrument cluster
219On-board computer and displays Z

Safety systems
Problem Possible causes/consequences and
M Solutions
J
The red brake system
warning lamp comes on
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 circumstances.
X Secure the vehicle against rolling away (Y page 141).
X Do not add brake fluid. Topping up will not remedy the
malfunction.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. !
The yellow ABS warning
lamp is lit while the
engine is running.
ABS (Anti-lock Brake System) is deactivated due to a malfunction.
BAS (Brake Assist), COLLISION PREVENTION ASSIST, ESP
®
(Electronic Stability Program), PRE-SAFE ®
,t he HOLD function and
hill start 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 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. 220
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
!
The yellow ABS warning
lamp is lit while the
engine is running.
ABS is temporarily unavailable. BAS, COLLISION PREVENTION
ASSIST, ESP
®
, EBD (electronic brake force distribution),
PRE-SAFE ®
, the HOLD function and hill start assist, for example,
are therefore also deactivated.
Possible causes are:
R Self-diagnosis is not yet complete.
R The on-board voltage may be insufficient.
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 a risk of an accident.
X Carefully drive a short distance on a suitable stretch of road,
making slight steering movements at a speed above 12 mph
(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 Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
221On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
!
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds.
EBD is malfunctioning. Therefore, ABS, BAS, COLLISION
PREVENTION ASSIST, ESP
®
, PRE-SAFE ®
, the HOLD function and
hill-start assist are also not available, for example.
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. J֌!
The red brake warning
lamp, the yellow ESP
®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running. ABS and ESP
®
are malfunctioning. Therefore, BAS, COLLISION
PREVENTION ASSIST, EBD, PRE-SAFE ®
, the HOLD function and
hill-start assist, for example, are not available either.
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. 222
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
÷
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 ®
.
For exceptions, see: (Y page 63).å
The yellow ESP
®
OFF
warning lamp is lit while
the engine is running. ESP
®
and ESP ®
trailer stabilization are deactivated. ESP ®
will not
stabilize the vehicle if it starts to skid or if a wheel starts to spin.
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 ®
.
For exceptions, see: (Y page 63).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Have ESP ®
checked at a qualified specialist workshop. ֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, COLLISION PREVENTION ASSIST, PRE-SAFE ®
, the
HOLD function and hill start assist 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 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. Warning and indicator lamps in the instrument cluster
223On-board computer and displays Z