2012 MERCEDES-BENZ E-CLASS CABRIOLET brake

Display messages Possible causes/consequences and
M Solutions
b
Left
mirror indica‐
tor or
Right mir‐ ror indicator The turn signal in the left-hand or right-hand exterior mirror is
faulty.
X
Chec kwhether you are permitted to replace the bulb yourself
(Y page 133).
or
X Visit a qualified specialist workshop. b
Third brake lamp The third brake lamp is faulty.
X
Check whether you are permitted to replace the bulb yourself
(Y page 133).
or
X Visit a qualified specialist workshop. b
Left-hand tail
lamp/brake
lamp orRight-hand
tail lamp/brake
lamp The left or right-hand tail lamp/brake lamp is faulty.
X
Check whether you are permitted to replace the bulb yourself
(Y page 133).
or
X Visit a qualified specialist workshop. b
Left main
beam orRight main
beam The left or right-hand high beam is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 133).
or
X Visit a qualified specialist workshop. b
Left
licence plate
lamp orRight
licence plate lamp The left or right-hand licence plate lamp is faulty.
X
Check whether you are permitted to replace the bulb yourself
(Y page 133).
or
X Visit a qualified specialist workshop. b
Left fog lamp
or
Right fog lamp The left-hand or right-hand front foglamp is faulty.
X
Check whether you are permitted to replace the bulb yourself
(Y page 133).
or
X Visit a qualified specialist workshop. Display messages
257On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
ë
off The HOLD function is deactivated. The vehicle is skidding.
Aw
arning tone also sounds.
X Reactivate the HOLD function later (Y page 198). The HOLD function is deactivated. When the brak
epedal is firmly
depressed, an activation condition is not fulfilled.
Aw arning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 198). Radar sensor deac‐
tivated See Own‐
er's Manual The radar sensor system is deactivated.
X
Chec kwhether or not the radar sensor system may be activated
(Y page 382).
X Activate the radar sensor system (Y page 245).Radar sensor deac‐
tivated autom. See
Owner's Manual Vehicles with a navigation system: the vehicle is close to a radio
telescope facility and is therefore prohibited from transmitting any
radar signals. The radar sensor system has switched off automat-
ically (Y
page 382).
If DISTRONIC PLUS was activated, it is no longer available. A
warning tone also sounds.
If Blind Spot Assist or Active Blind Spot Assist was activated, it is
no longer available. The yellow 9indicator lamps also light up
in the exterior mirrors.
BAS PLUS (Brake Assist PLUS) and PRE-SAFE ®
Brake are then also
unavailable.
X Drive on.
Once you have moved far enough away from the radio telescope,
the above functions are available again. Vehicles with Becker
®
MAP PILOT: if the Becker ®
MAP PILOT is
not connected, the radar sensor system is deactivated automati-
cally.
BAS PLUS, DISTRONIC PLUS, Blind Spot Assist or Active Blind
Spot Assist and PRE-SAFE ®
Brake are unavailable.
X Connect the Becker ®
MAP PILOT; see the separate operating
instructions. Display messages
263On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
DISTRONIC PLUS cur‐
rently unavailable
See Owner's Manual DISTRONIC PLU
Sis temporarily inoperative. Possible causes:
R the function is impaired due to heavy rain or snow.
R the sensors in the radiator trim and in the bumpers are dirty.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Aw arning tone also sounds.
Once the causes listed abov eno longer apply, the display message
goes out.
DISTRONIC 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 177).
X Clean the sensors in the radiator trim and in the bumpers
(Y page 317).
X Restart the engine. DISTRONIC PLUS
inoperative DISTRONIC PLUS is faulty.
BAS PLUS and PRE-SAFE
®
Brake may also have failed.
Aw arning tone also sounds.
X Visi taqualified specialist workshop. DISTRONIC PLUS
inactive You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
X
Remove your foot from the accelerator pedal. DISTRONIC PLUS
--- km/h An activation condition for DISTRONIC PLUS is not fulfilled.
X
Check the activation conditions for DISTRONIC PLUS
(Y page 188). DISTRONIC PLUS and
SPEEDTRONIC DISTRONIC PLUS and SPEEDTRONIC are faulty. A warning tone
also sounds.
X Visit a qualified specialist workshop. Cruise control and
SPEEDTRONIC inop‐
erative SPEEDTRONIC and cruise control are malfunctioning.
Aw arning tone also sounds.
X Visi taqualified specialist workshop. Display messages
267On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
M? The bonne
tis open. Awarning tone also sounds.
CLS Shooting Brake: the bonnet is open. A warning tone also
sounds.
G WARNING
The open bonne tmay then bloc kyour view when the vehicle is in
motion.
There is a risk of accident.
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 177).
X Close the bonnet.
If the active bonnet (pedestrian protection) has been triggered:
X Reset the bonnet (Y page 306).
X Close the bonnet. Active bonnet mal‐
function See Own‐
er's Manual The active bonnet (pedestrian protection) is not active due to a
malfunction.
The active bonnet (pedestrian protection) is not active due to a
malfunction or because it has already been triggered.
X Visit a qualified specialist workshop. C At least one door is open.
Awarning tone also sounds.
X Close all doors. _
Rear left seat
backrest not
locked or
Rear right seat back‐
rest not locked The backres
tinthe rear is not engaged on the left-hand and/or
right-hand side. Awarning tone also sounds.
X Push the backres tback until it engages. _
Front left seat
backrest not
locked or
Front right seat back‐
rest not locked The driver's or front-passenger seat backres
tis not engaged. A
warning tone also sounds.
X Push the backrest back until it engages. Display messages
271On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
j
Check trailer
hitch lock The trailer tow hitch is no
tcorrectly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Apply the parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 222). &
inoperative Bat‐
tery low The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on (Y
page 149).
X Drive for a longer distance.
The battery is being charged. The auxiliary heating is operational
again as soon as the on-board electrical system voltage is suf-
ficient. &
inoperative
Refuel
vehicle There is too little fuel in the fuel tank.T
he auxiliary heating cannot
be switched on (Y page 149).
X Refuel at the nearest filling station. &
inoperative See
Owner's Man. The auxiliary heating has a temporary malfunction or is faulty.
X
When the vehicle is on alevel surface and the engine has cooled
down, make up to four attempts to switch on the auxiliary heat-
ing, waiting several minutes between each attempt
(Y page 149).
X If the auxiliary heating does not switch on, consult a qualified
specialist workshop. J
Close boot separa‐
tor Cabriolet: the boot separator is open.
X
Close the boot separator (Y page 99).Ð
Power
steering mal‐
function See Own‐
er's Manual The power steering assistance is faulty.
Aw
arning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a ris kofaccident.
X Check whethe ryou are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified
specialist workshop.
X If you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop. 272
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
Â
Remove starting
button, then
insert key The KEYLESS-GO key is no
tcontinually detected.
KEYLESS-GO is temporarily malfunctioning or is defective. Awarn-
ing tone also sounds.
X Insert the key into the ignition lock and turn it to the desired
position.
X Visi taqualified specialist workshop. Â
Close doors to
lock vehicle At least one door is open.
Awarning tone also sounds.
X Close all doors and loc kthe vehicle again. Warning and indicator lamps in the
instrument cluster Warning and indicator lamps over-
view
L Dipped-beam headlamps
(Ypage 124)
T Side lamps (Y page 125)
K Main-beam headlamps
(Ypage 127)
#! Turn signals (Y page 126)
R Rear foglamp (Y page 125)
ü Seat belts (Y page 276)
J Brakes (Ypage 277)
! ABS (Ypage 277)
ä ESP®
(Y page 278)
å ESP®
OFF (Y page 278)
6 SRS (Ypage 280)
; Engine diagnostics
(Ypage 280)
8 Reserve fuel (Y page 281)
? Coolant (Ypage 281)
· Distance warning signal
(Ypage 283)
% Diesel engine: preglow
(Ypage 160) Warning and indicator lamps in the instrument cluster
275On-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 run-
ning. A warning tone
also sounds. There is insufficient brake fluid in the brake fluid reservoir.
G WARNING
The 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 Secure the vehicle against rolling away (Y page 177).
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. !
The yellow ABS warning
lamp is lit while the
engine is running. ABS (Anti-lock Brake System) has been deactivated due to a fault.
For this reason, BAS (Brake Assist), BAS PLUS, ESP ®
(Electronic
Stability Program), PRE-SAFE ®
,P RE-SAFE ®
Brake ,the HOLD func-
tion, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation are also deactivated, for example.
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 affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
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 trans-
mission, will not be available. Warning and indicator lamps in the instrument cluster
277On-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 not available due to a malfunction. Therefore, ABS, BAS,
BAS PLUS, ESP
®
, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD func-
tion, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation, 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 affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Jäå!
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 not available due to a fault. Therefore, BAS, BAS
PLUS, EBD,P RE-SAFE®
,P RE-SAFE ®
Brake, the HOLD function, hill
start assist, the adaptive brake lights and ESP ®
trailer stabilisa-
tion, for example, are no tavailable 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 affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The dange rofskidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visi taqualified specialist workshop. 278
Warning and indicator lamps in the instrument clusterOn-board computer and displays