2015 MERCEDES-BENZ E-CLASS CABRIOLET check engine

the power output of the engine, and conse-
quently the vehicle's gradient-climbing capa-
bility, decrease with increasing altitude.
Folding the ball coupling in/out
Folding out the ball coupling G
WARNING
If the ball coupling is not correctly engaged,
the trailer can detach. There is a risk of an
accident.
Always engage the ball coupling as described. G
WARNING
If you release the ball coupling or it does not
engage correctly when folding in, it will swing out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstructed. Always make sure that the ball coupling engages when folding in.
Before you can tow a trailer with your vehicle,
you must fold out the ball coupling. The release wheel is located behind the left-
hand side trim panel in the boot.
Opening the cover:
X Turn handle :around anti-clockwise and
fold cover ;down. Unlocking and folding out the ball coupling:
X Pull out release wheel ?.
X Turn release wheel ?anti-clockwise until the
ball coupling releases and folds out from
under the rear bumper. Indicator lamp =
flashes. X
Pull the ball coupling in the direction of the
arrow until it engages in a vertical position.
The trailer power socket is integrated into the ball coupling and swivels out with it.
Indicator lamp =goes out.
The multifunction display shows the
Trailer hitch Check lock mech. Trailer hitch Check lock mech. mes-
sage until the ball coupling is engaged.
X Remove the protective covering from the ball
coupling and store it in a safe place.
X Make sure that the ball of the ball coupling is
clean and greased.
HYBRID vehicles : make sure that you read the
"HYBRID" Supplement included in the vehicle
literature. Otherwise, you may not recognise
dangers. 210
Towing a trailerDriving an
d parking

Important safety notes
G
WARNING
Operating the integrated information systems and communications equipment in the vehicle
while driving will distract you from traffic con-
ditions. You could then lose control of the
vehicle. There is a risk of an accident.
Only operate these devices if road traffic con-
ditions permit. If you are unsure about the
surrounding conditions, pull over to a safe
location and make entries only while the vehi-
cle is stationary.
You must observe the legal requirements for the country in which you are currently driving whenoperating the on-board computer. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognise function
restrictions relevant to safety. The operating
safety of your vehicle may be impaired. There is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
The on-board computer only shows messages or warnings from certain systems in the multifunc-tion display. You should therefore make sure
your vehicle is operating safely at all times.
If the operating safety of your vehicle is
impaired, park the vehicle safely as soon as pos- sible. Contact a qualified specialist workshop.
For an overview; see the instrument cluster illus-
tration (Y page 31). Displays and operation
Speedometer with segments
The segments in the speedometer indicate
which speed range is available.
R Cruise control activated (Y page 163):
The segments light up from the stored speed to the type-tested maximum speed.
R Variable SPEEDTRONIC activated
(Y page 165): The segments light up from the start of the
scale to the selected limit speed.
R DISTRONIC PLUS activated (Y page 168):
One or two segments in the set speed range
light up.
R DISTRONIC PLUS detects a vehicle in front:
The segments between the speed of the vehi-
cle in front and the stored speed light up. Rev counter
! Do not drive in the overrevving range. Doing
so will damage the engine.
The red band in the rev counter indicates the
engine's overrevving range.
The fuel supply is interrupted to protect the
engine when the red band is reached. Outside temperature display
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Bear in mind that the outside temperature dis-
play indicates the measured air temperature
and not the road surface temperature.
The outside temperature display is in the multi-
function display (Y page 215).
The multifunction display shows changes in the
outside temperature with a delay. Coolant temperature gauge
G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade.
The coolant temperature gauge is in the instru-
ment cluster on the left-hand side (Y page 31). Displays and operation
213On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions J
Release parking Release parking
brake brake You are driving with the parking brake applied. A warning tone also
sounds.
X Release the parking brake. J
Check brake fluid Check brake fluid
level level There is insufficient brake fluid in the brake fluid reservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
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 circumstances.
X Safeguard the vehicle against rolling away (Y page 157).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the fault. #
Check Check
brake
brakepad
padwear
wear The brake pads/linings have reached their wear limit.
X Consult a qualified specialist workshop. G
Inoperative
Inoperative One or more main features of the Mercedes-Benz Contact system are
malfunctioning.
X Consult a qualified specialist workshop. Collision Preven‐
Collision Preven‐
tion Assist Plus tion Assist Plus
currently unavaila‐ currently unavaila‐
ble ble
See
SeeOwner's
Owner's Man‐
Man‐
ual
ual COLLISION PREVENTION ASSIST PLUS is temporarily inoperative.
Possible causes:
R the radar sensor system is temporarily inoperative, e.g. due to elec-
tromagnetic 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
Once the causes listed above no longer apply, the display message
goes out.
COLLISION PREVENTION ASSIST PLUS 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 Safeguard the vehicle against rolling away (Y page 157).
X Restart the engine. Collision Preven‐ Collision Preven‐
tion Assist Plus tion Assist Plus
inoperative inoperative COLLISION PREVENTION ASSIST PLUS is temporarily inoperative due
to a malfunction. Adaptive Brake Assist may also have failed.
X Consult a qualified specialist workshop. 232
Display
messagesOn-board computer and displays

Engine
Display messages
Possible causes/consequences and
M
MSolutions +
Top up coolant See Top up coolant See
Owner's Manual Owner's Manual The coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, observing the warning notes before doing so
(Y page 292).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist workshop. ? The fan motor is faulty.
X If the coolant temperature is below 120 †, you can continue driving
to the nearest qualified specialist workshop.
X Avoid putting the engine under heavy load as you do so, e.g. driving
in mountainous terrain and stop-start traffic. ?
Coolant Stop vehi‐ Coolant Stop vehi‐
cle Switch engine cle Switch engine
off off The coolant is too hot.
A warning tone also sounds.
G WARNING
Never drive with an overheated engine. Driving when your engine is
overheated can cause some fluids which may have leaked into the
engine compartment to catch fire.
In addition, steam from an overheated engine can cause serious
burns, which can occur just by opening the bonnet.
There is a risk of injury.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 157).
X Wait until the engine has cooled down.
X Make sure that the air supply to the engine radiator is not blocked,
e.g. by frozen slush.
X Do not start the engine again until the display message goes out and
the coolant temperature is below 120 †. The engine may otherwisebe damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, consult a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 120 †. 238
Display messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions #
See Owner's Manual See Owner's Manual The battery is not being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
! Do not continue driving. The engine could otherwise overheat.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 157).
X Consult a qualified specialist workshop. #
Stop vehicle See Stop vehicle See
Owner's Manual Owner's Manual The battery is no longer being charged and the battery charge level is
too low.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 157).
X Observe the instructions in the #See SeeOwner's
Owner's Manual
Manualdisplay
message.
X Consult a qualified specialist workshop. 4
Check Check
eng.
eng.oil
oillev.
lev.
when
when next
nextrefuelling
refuelling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
! Avoid long journeys when there is too little coolant in the cooling
system. Otherwise the engine will be damaged.
X Check the oil level when next refuelling, at the latest (Y page 291).
X If necessary, top up the engine oil (Y page 292).
X Have the engine checked at a qualified specialist workshop if the
engine oil needs topping up more often than usual.
Information on approved engine oils can be obtained from any quali-
fied specialist workshop or on the Internet at http://bevo.mercedes-
benz.com. 8
Reserve fuel level Reserve fuel level The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level drops
into the reserve range.
X Refuel at the nearest filling station. C There is very little fuel in the fuel tank.
The auxiliary heating cannot be operated.
X Refuel at the nearest filling station without fail. Display
messages
239On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions ¸
Please replace air Please replace air
filter filter Vehicles with a diesel engine: the engine air filter is dirty and must be
replaced.
X Consult a qualified specialist workshop. !
Clean the fuel fil‐ Clean the fuel fil‐
ter ter Vehicles with a diesel engine: there is water in the fuel filter. The water
must be drained off.
X Consult a qualified specialist workshop. ¯
Refill AdBlue at Refill AdBlue at
workshop See Own‐ workshop See Own‐
er's Manual er's Manual The AdBlue
®
level has fallen below the reserve range. A warning tone
also sounds.
X Have AdBlue ®
refilled as soon as possible at a qualified specialist
workshop. ¯
Refill AdBlue at Refill AdBlue at
workshop No start workshop No start
in .. km in .. km The AdBlue
®
level is only sufficient for the indicated distance. A warn-
ing tone also sounds.
X Have AdBlue ®
refilled as soon as possible at a qualified specialist
workshop. ¯
Refill AdBlue at Refill AdBlue at
workshop workshop
Eng.
Eng. start
start
not possible
not possible The AdBlue
®
tank is empty. A warning tone also sounds. You can no
longer start the engine.
X Consult a qualified specialist workshop immediately. ¯
Check AdBlue See Check AdBlue See
Owner's Manual Owner's Manual The AdBlue
®
system is malfunctioning. A warning tone also sounds.
X Consult a qualified specialist workshop. ¯
Eng. start not pos‐ Eng. start not pos‐
sible in ..km sible in ..km The AdBlue
®
system is malfunctioning. A warning tone also sounds.
X Consult a qualified specialist workshop immediately. ¯
Eng. start not pos‐ Eng. start not pos‐
sible sible The AdBlue
®
system is malfunctioning. A warning tone also sounds.
You can no longer start the engine.
X Consult a qualified specialist workshop immediately. 240
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions DISTRONIC PLUS cur‐
DISTRONIC PLUS cur‐
rently unavailable rently unavailable
See Owner's Manual See Owner's Manual DISTRONIC PLUS is temporarily inoperative.
Steering Assist and Stop&Go Pilot are temporarily inoperative.
Possible causes:
R the radar sensor system is temporarily inoperative, e.g. due to elec-
tromagnetic 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
A warning tone also sounds.
Once the causes listed above no longer apply, the display message
goes out.
DISTRONIC PLUS 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 Safeguard the vehicle against rolling away (Y page 157).
X Restart the engine. DISTRONIC DISTRONIC
PLUS
PLUSinop‐
inop‐
erative
erative DISTRONIC PLUS is faulty.
The following may have also failed:
R BAS PLUS with Cross-Traffic Assist
R PRE-SAFE ®
Brake
R Steering Assist and Stop&Go Pilot
A warning tone also sounds.
X Consult a qualified specialist workshop. DISTRONIC PLUS sus‐ DISTRONIC PLUS sus‐
pended pended 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
DISTRONIC PLUS
- - - km/h - - - km/h An activation condition for DISTRONIC PLUS is not fulfilled.
X Check the activation conditions for DISTRONIC PLUS (Y page 168).DISTRONIC PLUS and
DISTRONIC PLUS and
SPEEDTRONIC inoper‐ SPEEDTRONIC inoper‐
ative ative DISTRONIC PLUS and SPEEDTRONIC are faulty.
Steering Assist and Stop&Go Pilot are therefore also unavailable.
A warning tone also sounds.
X Consult a qualified specialist workshop. 244
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions j
Check Check
trailer
trailer hitch
hitch
lock
lock The trailer tow hitch is not correctly engaged.
A warning tone also sounds.
G WARNING
If the ball coupling is not engaged, the trailer may come loose. There
is a risk of an accident.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Apply the parking brake.
X Engage the trailer coupling's ball coupling in the end position
(Y page 210). &
inoperative inoperative
Battery
Battery
Low
Low The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on (Y page 132).
X Drive for a considerable distance.
The battery charges. The auxiliary heating is operational again as
soon as the on-board electrical system voltage is sufficient. &
inoperative Refuel inoperative Refuel
vehicle vehicle There is too little fuel in the fuel tank. The auxiliary heating cannot be
switched on (Y page 132).
X Refuel at the nearest filling station. &
inoperative inoperative
See
SeeOwn‐
Own‐
er's Man.
er's Man. The auxiliary heating is temporarily malfunctioning or faulty.
X When the vehicle is on a level surface and the engine has cooled
down, make up to four attempts to switch on the auxiliary heating,
waiting several minutes between each attempt (Y page 132).
X If the auxiliary heating does not switch on, consult a qualified spe-
cialist workshop. Telephone Telephone
No
Noservice
service Your vehicle is outside the network provider's transmitter/receiver
range.
X Wait until the mobile phone operational readiness symbol appears
in the multifunction display. Ð
Power steering mal‐ Power steering mal‐
function See Own‐ function See Own‐
er's Manual er's Manual The power steering assistance is faulty.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident.
X Check whether you 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. Display
messages
251On-board computer and displays Z