check engine MERCEDES-BENZ SLK ROADSTER 2012 Owner's Manual

Display messages Possible causes/consequences and
M Solutions
# The battery is no
tbeing charged.
Aw arning tone also sounds.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Open the bonnet.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is OK:
X Visit a qualified specialist workshop. 4
Check eng. oil
lev. when next
refuelling The engine oil level has dropped to the minimum level.
Aw
arning tone also sounds.
X Chec kthe oil level when next refuelling, at the latest
(Y page 250).
X If necessary, top up the engine oil (Y page 250).
X Have the engine checked at a qualified specialist workshop if
the engine oil needs topping up more often than usual. 8
Reserve fuel level The fuel level has dropped into the reserve range.
X
Refuel at the nearest filling station. C There is only a very small amount of fuel in the fuel tank.
X
Refuel at the nearest filling station without fail. 212
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
The HOLD function is deactivated. Whe
nthe brake pedal 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 165). 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 312).
DISTRONI CPLUS (Y page 156) is deactivated automatically if it is
activated. Awarning tone also sounds.
BAS PLUS (Brake Assist PLUS) (Y page 54)and PRE-SAFE ®
Brake
(Y page 59) are then also not available.
X Drive on.
Once you have moved fa renough 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 rada rsensor system is deactivated automati-
cally.
BAS PLUS, DISTRONIC PLUS and PRE-SAFE ®
Brake are not avail-
able.
X Connect the Becker ®
MAP PILOT; see the separate operating
instructions. Radar sensor
deactivated See
Owner's Manual The radar sensor system is deactivated.
X
Check whether or not the radar sensor system may be activated
(Y page 312).
X Switch on the radar sensor system (Y page 194).Parking Guidance
inoperative Parking Guidance is malfunctioning (
Ypage 170).
X Restart the engine.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. 214
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
DISTRONIC PLUS
currently unavail‐
able See Owner's
Manual DISTRONIC is deactivated and temporarily inoperative. Possible
causes:
R
the DISTRONIC PLUS cover in the radiator grille is dirty.
R function is impaired due to heavy rain or snow.
R the sensors in the bumpers are dirty.
R the rada rsensor 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.
If the display message does no tdisappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Engage the electric parking brake.
X Clean the DISTRONIC PLUS cover in the radiator grille
(Y page 257).
X Clean the bumpers (Y page 257).
X Restar tthe engine.
If the system detects that the sensors are fully operational, the
display message disappears.
DISTRONIC is operational again. 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
override 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 156). DISTRONIC PLUS and
SPEEDTRONIC
inoperative DISTRONIC PLUS and SPEEDTRONIC are faulty. A warning tone
also sounds.
X
Visit a qualified specialist workshop. 216
Display messagesOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
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. G
Risk of accident
ABS and ESP ®
are malfunctioning. Therefore, BAS, BAS PLUS,
EBD, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD function, hill start
assist and the adaptive brake lights, for example, are not available
either.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
ATTENTION ASSIST is deactivated.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. ÷
The yellow ESP
®
warn-
ing lamp flashes while
the vehicle is in motion. G
Risk of accident
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 ®
.
For exceptions, see: (Y page 56).å
The yellow ESP
®
OFF
warning lamp is lit while
the engine is running. G
Risk of accident
ESP ®
is deactivated. ESP ®
will not stabilise the vehicle if it starts
to skid or if a wheel starts to spin.
X Reactivate ESP ®
.
For exceptions, see: (Y page 56).
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. 228
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
M
AMG vehicles only:
The yellow SPORT han-
dling mode warning
lamp is lit while the
engine is running.
G
Risk of accident
SPORT handling mode is activated. ESP ®
only stabilises the vehi-
cle in extreme situations. ESP ®
intervention may not be able to
provide sufficient assistance in such situations, and the vehicle
may start to skid.
X Reactivate ESP ®
.
For exceptions, see: (Y page 56).
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. G
Risk of accident
ESP ®
, BAS, BAS PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD
function, hill start assist and the adaptive brake lights are not
available due to a malfunction .ESP ®
will not stabilise the vehicle
if it starts to skid or if a wheel starts to spin.
The brake system continues to function normally, bu twithout the
functions listed above.
ATTENTION ASSIST is deactivated.
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
229On-board computer and displays Z

Engine
Problem Possible causes/consequences and
M Solutions
;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running.
There may be a fault, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engin emay
be running in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop. Vehicles with a diesel engine: the fuel tan
khas been run dry
(Y page 145).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emer-
gency running mode is cancelled. The vehicle need no tbe
checked. 8
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
X
Refuel at the nearest filling station. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the
star toft he scale. The temperature sensor for the coolant temperature gauge is
faulty.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.
X Engage the electric parking brake.
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
231On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator
may be blocked or the electric engine radiator fan may be mal-
functioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X
Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Let the engine and coolant cool down.
X Check the coolant level and top up the coolant (Y page 251).
Observe the warning notes as you do so.
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X If the coolant temperature is less than 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving on
mountain roads and stop-start traffic. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
The coolant temperature has exceeded 120 †. The airflow to the
engine radiator may be blocked or the coolant level may be too
low.
The engine is not being cooled sufficiently and may be damaged.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Let the engine and coolant cool down.
X Check the coolant level and top up the coolant (Y page 251).
Observe the warning notes as you do so.
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X If the coolant temperature is less than 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving on
mountain roads and stop-start traffic. 232
Warning and indicator lamps in the instrument clusterOn-board computer and displays

X
Lower the bonnet and let it fall from a
heightofa pproximately 20 cm.
X Check that the bonnet has engaged prop-
erly.
If the bonnet can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force. Radiator
i Vehicles with adiesel engine: do not
cover the radiator. Do not use thermal
mats, insect protection covers or anything
similar. Doing so can cause the Onboard
Diagnostics System to display inaccurate
values. Some of these values are legally
required and must be correct. Engine oil
Notes on oil level Depending on driving style, the vehicle con-
sumes up to 0.
8lof oil per 1,000 km .The oil
consumption may be higher than this when
the vehicle is new or if you frequently drive at
high engine speeds.
AMG vehicles: before operation on race
tracks, check the oil level and (Y page 250)
top up if necessary (Y page 250). Race track
operation is only permitted with a maximum
engine oil level.
Depending on the engine, the oil dipstick may
be installed at a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly: wait about 30 minutes
before carrying out the measurement. Checking the oil level using the oil dip-
stick
Example: vehicles with a petrol engine
Example: vehicles with a diesel engine
X
Pull oil dipstick :out of the oil dipstick
tube.
X Wipe off oil dipstick :.
X Slowly slide oil dipstick :into the guide
tube to the stop, and take it out again.
If the level is between MIN mark =and
MAX mark ;, the oil level is correct.
X If the oil level has dropped to MIN mark
= or below, add 0.5to 1.0litre of engine
oil.
Adding engine oil G
WARNING
If engine oil comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any engine oil on hot
engine parts. 250
Engine compartmentMaintenance and care

H
Environmental note
When topping up the oil, take care not to spill
any. If oil enters the soil or waterways, it is
harmful to the environment.
! Only use engine oils and oil filters that
have been approved for vehicles with a
service system. You can obtain a list of the
engine oils and oil filters tested and
approved in accordance with the
Mercedes-Benz Specifications for Service
Products at any Mercedes-Benz Service
Centre.
Damage to the engine or exhaust system is
caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R changing the engine oil and oil filter after
missing the change interval required by
the service system
R using engine oil additives
! Do not add too much oil. Topping up with
too much engine oil can result in damage
to the engine or to the catalytic converter.
Have excess engine oil siphoned off. Example: engine oil cap
X
Turn cap :anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or under the MIN mark
on the oil dipstick, add 0.5 to 1.0 litre of
engine oil. X
Replace cap :on the filler neck and turn
clockwise.
Make sure that the cap locks into place
securely.
X Chec kthe oil level again with the oil dip-
stick (Y page 250).
Further information on engine oil
(Y page 307). Checking and adding other service
products
Checking the coolant level G
WARNING
The cooling system is pressurised. Therefore,
only unscrew the cap once the engine has
cooled down. The coolant temperature gauge
must display less than 70 †.Otherwise, you
could be scalded if hot coolant escapes. X
Park the vehicle on a level surface.
Only check the coolant level if the vehicle
is on a level surface and the engine has
cooled down.
X Turn the key to position 2in the ignition
lock (Y page 127).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 127).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
70 †.
X Turn the key to position 0(Ypage 127) in
the ignition lock. Engine compartment
251Maintenance and care Z

G
WARNING
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have
been tested and approved for yourv ehicle by
Mercedes-Benz .These batteries provide
increased impact protection to prevent vehi-
cle occupants from suffering acid burns
should the battery be damaged in the event
of an accident.
To prevent acid burns, observe the following
safety notes when handling batteries:
R do not lean over the battery.
R do not place any metal objects on a battery.
Otherwise, you could cause a short circuit
and the battery's gas mixture could ignite.
R make sure that you do not create an elec-
trostatic charge, e.g. by wearing synthetic
clothing or as a result of friction on fabrics.
Therefore, you should not pull or slide the
battery over carpets or other synthetic
materials.
R never touch the battery first. To discharge
a possible electrostatic charge, step out of
the vehicle first and touch the bodywork.
R do not wipe the battery using a cloth. The
battery may explode as a result of electro-
static charge or due to flying sparks.
! Switch off the engine and remove the key
before disconnecting the terminal clamps
from the battery. On vehicles with KEY-
LESS-GO, make sure that the ignition is
switched off. Check that all the indicator
lamps in the instrumentc luster are off.You
may otherwise destroy electronic compo-
nents, such as the alternator.
i When you park the vehicle, remove the
key if you do not require any electrical con-
sumers. The vehicle will then use very little
energy, thus conserving battery power.
Mercedes-Benz recommends that you do not
carry out work on batteries yourself, e.g.
removing or charging. Have this work per-
formed at a qualified specialist workshop. Installation location of the battery
Your vehicle is equipped with a battery in the
engine compartment.Iti s located on the front
bulkhead under the water tank on the right-
hand side of the vehicle when viewed in the
direction of travel.
X Apply the electric parking brake and shift
the transmission to position P.
X Switch off all electrical consumers (e.g.
radio, blower, etc.).
X Turn the key to position 0(Ypage 127) in
the ignition lock and remove it, or, on vehi-
cles with KEYLESS-GO, make sure that the
ignition has been switched off
(Y page 127). All indicator lamps in the
instrument cluster must be off.
X Open the bonnet (Y page 248). X
Turn fasteners ;a quarter of a turn.
X Remove water tank :.
The battery is located under water
tank :. Disconnecting the battery
! Always disconnect the battery in
the order described below. Never swap the
terminal clamps. You may otherwise dam-
age the vehicle electronics.
In vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The vehicle
is secured against rolling away. You can
then no longer move the vehicle. 274
BatteryBreakdown assistance