2015 MERCEDES-BENZ SLK-CLASS ROADSTER engine

General notes
SLK 250
:ECO start/stop display
If the è ECO symbol is shown in green in
the multifunction display, the ECO start/stop
function switches the engine off automati-
cally if the vehicle stops moving.
Every time you switch on the engine using the SmartKey or the Start/Stop button, the ECO
start/stop function is activated.
If the ECO start/stop function has been man- ually deactivated ( Ypage 147) or a malfunc-
tion has caused the system to be deactivated, the è ECO symbol is not displayed.
SLK 350
:ECO start/stop display
If the engine has been switched off automat-
ically by the ECO start/stop function, the è ECO symbol is shown in the multifunc-
tion display.
Every time you switch on the engine using the SmartKey or the Start/Stop button, the ECO
start/stop function is activated. SLK 55 AMG
:ECO start/stop display
If the è ECO symbol is shown in green in
the multifunction display, the ECO start/stop
function switches the engine off automati-
cally if the vehicle stops moving.
Every time you switch on the engine using the SmartKey or the Start/Stop button, the ECO
start/stop function is activated.
If the ECO start/stop function has been man- ually deactivated ( Ypage 147) or a malfunc-
tion has caused the system to be deactivated, the è ECO symbol is not displayed.
The ECO start/stop function is only available
in drive program C.
iIf automatic cylinder shut-off is active in
drive program C, then 4, the number of
active cylinders, is also shown in the è
ECO symbol. This means that the engine is operating with four cylinders.
If cylinder shut-off is not active, the engine
will operate with all eight cylinders. In this case, 8, the number of active cylinders, is
shown in the èECO symbol.
Automatic engine switch-off
Operation (SLK 250)
The ECO start/stop function is operational
and the èECO symbol is displayed in
green in the multifunction display, if:
R the indicator lamp in the ECO button is litgreen.
R the outside temperature is within the range
that is suitable for the system.
R the engine is at normal operating temper-ature.
144Driving
Driving and parking

Rthe set temperature for the vehicle interior
has been reached.
R the battery is sufficiently charged.
R the system detects that the windshield is
not fogged up when the air-conditioning
system is switched on.
R the hood is closed.
R the driver's door is closed and the driver's
seat belt is fastened.
If the conditions for automatic engine switch- off are not all fulfilled, the èECO symbol is
lit yellow.
iAll of the vehicle's systems remain active
when the engine is stopped automatically.
iThe engine can be switched off automat-
ically a maximum of four times (first stop
and three subsequent stops) in succession.
The è ECO symbol is shown in yellow in
the multifunction display after the engine
has been started automatically for the
fourth time. When the èECO symbol is
shown in green in the multifunction display,
automatic engine switch-off is again possi- ble.
iThe HOLD function can be activated if the
engine has been switched off automati-
cally. It is then not necessary to continue
applying the brakes during the automatic
stop phase. When you depress the accel-
erator pedal, the engine starts automati-
cally and the braking effect of the HOLD
function is deactivated.
Vehicles with manual transmission (SLK
250)
The ECO start/stop function switches off the
engine automatically at low speeds.
X Brake the vehicle.
X Engage neutral N(follow gearshift instruc-
tion :to engage neutral N, if necessary).
X Release the clutch pedal.
The engine is switched off automatically.
Vehicles with automatic transmission
(SLK 250)
If the vehicle is braked to a standstill in Dor N,
the ECO start/stop function switches off the engine automatically.
SLK 350
If the vehicle is braked to a standstill in Dor N,
the ECO start/stop function switches off the engine automatically.
The ECO start/stop function is operational
when:
R the indicator lamp in the ECO button is lit
green.
R the outside temperature is within the range
that is suitable for the system.
R the engine is at normal operating temper-
ature.
R the set temperature for the vehicle interior
has been reached.
R the battery is sufficiently charged.
R the system detects that the windshield is
not fogged up when the air-conditioning
system is switched on.
R the hood is closed.
R the driver's door is closed and the driver's
seat belt is fastened.
iAll of the vehicle's systems remain active
when the engine is stopped automatically.
iThe engine can be switched off automat-
ically a maximum of four times (first stop
and three subsequent stops) in succession.
iThe HOLD function can be activated if the
engine has been switched off automati-
cally. It is then not necessary to continue
applying the brakes during the automatic
Driving145
Driving an d parking
Z

stop phase. When you depress the accel-
erator pedal, the engine starts automati-
cally and the braking effect of the HOLD
function is deactivated.
SLK 55 AMG
If the vehicle is braked to a standstill in Dor N,
the ECO start/stop function switches off the engine automatically.
The ECO start/stop function is operational
and the èECO symbol is displayed in
green in the multifunction display, if:
R the indicator lamp in the ECO button is litgreen.
R the outside temperature is within the range
that is suitable for the system.
R the engine is at normal operating temper-ature.
R the set temperature for the vehicle interior
has been reached.
R the battery is sufficiently charged.
R the system detects that the windshield is
not fogged up when the air-conditioning
system is switched on.
R the hood is closed.
R the driver's door is closed and the driver's
seat belt is fastened.
If the conditions for automatic engine switch-
off are not all fulfilled, the èECO symbol is
lit yellow.
iAll of the vehicle's systems remain active
when the engine is stopped automatically.
iThe engine can be automatically switched
off an unlimited number of times.
iThe HOLD function can be activated if the
engine has been switched off automati-
cally. It is then not necessary to continue
applying the brakes during the automatic
stop phase. When you depress the accel-
erator pedal, the engine starts automati-
cally and the braking effect of the HOLD
function is deactivated.
Automatic engine start
Operation (SLK 250)
The engine starts automatically if:
R you switch off the ECO start/stop function
by pressing the ECO button.
R you engage reverse gear R.
R you unfasten your seat belt or open the
driver's door.
R the vehicle starts to roll.
R the brake system requires this.
R the temperature in the vehicle interior devi-
ates from the set range.
R the system detects moisture on the wind-
shield when the air-conditioning system is
switched on.
R the battery's condition of charge is too low.
Vehicles with manual transmission (SLK250)
!Only engage gear when the clutch pedal is
depressed.
The engine is started automatically if you: R fully depress the clutch pedal.
R depress the accelerator pedal.
Vehicles with automatic transmission
(SLK 250)
The engine is started automatically if you: R release the brake pedal in transmission position Dor Nwhen the HOLD function is
not active.
R depress the accelerator pedal.
R move the transmission out of position P.
iShifting the transmission to position P
does not start the engine.
iIf you shift the transmission from Rto D,
the ECO start/stop function is available
again once the èECO symbol reap-
pears in green in the multifunction display.
146Driving
Driving and parking

SLK 350
The engine starts automatically if:
R you switch off the ECO start/stop function
by pressing the ECO button.
R in transmission position Dor Nthe brake
pedal is released and the HOLD function is
not active.
R you depress the accelerator pedal.
R you engage reverse gear R.
R you move the transmission out of positionP.
R you unfasten your seat belt or open the
driver's door.
R the vehicle starts to roll.
R the brake system requires this.
R the temperature in the vehicle interior devi-
ates from the set range.
R the system detects moisture on the wind-
shield when the air-conditioning system is
switched on.
R the battery's condition of charge is too low.
iShifting the transmission to position P
does not start the engine.
SLK 55 AMG
The engine starts automatically if:
R you switch off the ECO start/stop function
by pressing the ECO button.
R in transmission position Dor Nthe brake
pedal is released and the HOLD function is
not active.
R you depress the accelerator pedal.
R you engage reverse gear R.
R you move the transmission out of positionP.
R you switch to drive program Sor M.
R you unfasten your seat belt or open the
driver's door.
R the vehicle starts to roll.
R the brake system requires this.
R the temperature in the vehicle interior devi-
ates from the set range. R
the system detects moisture on the wind-
shield when the air-conditioning system is
switched on.
R the battery's condition of charge is too low.
iShifting the transmission to position P
does not start the engine.
iIf you shift the transmission from Rto D,
the ECO start/stop function is available
again once the èECO symbol reap-
pears in green in the multifunction display.
Deactivating/activating the ECO start/
stop function
SLK 250
X To deactivate: press ECO button :.
Indicator lamp ;and the èECO sym-
bol in the multifunction display go out.
X To activate: press ECO button :.
Indicator lamp ;lights up.
If all conditions for automatic engine
switch-off ( Ypage 144) are fulfilled, the
è ECO symbol is shown in green in the
multifunction display.
If not all conditions for automatic engine
switch-off ( Ypage 144) are fulfilled, the
è ECO symbol is shown in yellow in the
multifunction display.
If this is the case, the ECO start/stop func-
tion is not available.
Conditions for the automatic engine
switch-off ( Ypage 144).
Driving147
Driving and parking
Z

iIf indicator lamp;is off, the ECO start/
stop function has been deactivated man-
ually or as the result of a malfunction. The
engine will then not be switched off auto-
matically when the vehicle stops.
iThe ECO start/stop function is activated
each time the engine is switched on.
SLK 350
X To deactivate: press ECO button :.
Indicator lamp ;goes out.
X To activate: press ECO button :.
Indicator lamp ;lights up.
iIf indicator lamp ;is off, the ECO start/
stop function has been deactivated man-
ually or as the result of a malfunction. The
engine will then not be switched off auto-
matically when the vehicle stops.
iThe ECO start/stop function is activated
each time the engine is switched on.
SLK 55 AMG
X To switch off: in drive program C, press
ECO button :.
or X Switch to drive program Sor M
( Y page 153).
Indicator lamp ;and the èECO sym-
bol in the multifunction display go out.
X To activate: press ECO button :.
Indicator lamp ;lights up. If drive pro-
gram Sor Mis active, the automatic trans-
mission switches to drive program C.
If all conditions for automatic engine
switch-off ( Ypage 144) are fulfilled, the
è ECO symbol is shown in green in the
multifunction display.
If not all conditions for automatic engine
switch-off ( Ypage 144) are fulfilled, the
è ECO symbol is shown in yellow in the
multifunction display.
If this is the case, the ECO start/stop func-
tion is not available.
Conditions for the automatic engine
switch-off ( Ypage 144).
iIf indicator lamp ;is off, the ECO start/
stop function has been deactivated man-
ually or as the result of a malfunction. The
engine will then not be switched off auto-
matically when the vehicle stops.
iEach time the engine is started, the ECO
start/stop function switches to the status
(on or off) that was selected before switch- ing off the engine.
148Driving
Driving and parking

Problems with the engine
ProblemPossible causes/consequences andMSolutions
The engine does not start.The HOLD function or DISTRONIC PLUS is activated.
X Deactivate the HOLD function ( Ypage 180) or DISTRONIC
PLUS ( Ypage 171).
X Try to start the engine again.
The engine does not
start. The starter motor
can be heard.R
There is a malfunction in the engine electronics.
R There is a malfunction in the fuel supply.
X Turn the SmartKey back to position 0in the ignition lock before
attempting to start the engine again.
or
X Press the Start/Stop button repeatedly until all indicator lamps
in the instrument cluster go out.
X Try to start the engine again ( Ypage 141). Avoid excessively
long and frequent attempts to start the engine as these will drain
the battery.
If the engine does not start after several attempts: X Consult a qualified specialist workshop.
The engine does not
start. You cannot hear
the starter motor.The on-board voltage is too low because the battery is too weak or
discharged.
X Jump-start the vehicle ( Ypage 303).
If the engine does not start despite attempts to jump-start it:
X Consult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high.
X Allow the starter motor to cool down for approximately two minutes.
X Try to start the engine again.
If the engine still does not start:
X Consult a qualified specialist workshop.
The engine is not run-
ning smoothly and ismisfiring.There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
X Have the cause rectified immediately at a qualified specialistworkshop.
Driving149
Driving and parking
Z

ProblemPossible causes/consequences andMSolutions
The coolant tempera-
ture gauge shows a
value above 248 ‡
(120 †). The coolant
warning lamp may also
be on and a warning
tone may sound.The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X Stop as soon as possible and allow the engine and the coolant to
cool down.
X Check the coolant level ( Ypage 283). Observe the warning
notes as you do so and add coolant if necessary.
If the coolant level is correct, the engine radiator fan may be faulty. The coolant is too hot and the engine is no longer being cooled sufficiently.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and start/stop traffic.
Manual transmission
Gear lever
!
Only engage gear when the clutch pedal is
depressed.
!When shifting between 5thand 6thgear,
you should always push the gear lever all
the way to the right. You could otherwise
shift unintentionally into 3rdor4th gear
and damage the transmission.
If you shift down at too high a speed (trans-
mission braking), this can cause the engine to overrev, leading to engine damage.
Never hold the vehicle stopped on a hill by
using the clutch pedal. There is otherwise a risk of damaging the clutch.
Gear lever k
Reverse gear
1 -6Forward gears
Engaging reverse gear
!
Only shift into reverse gear Rwhen the
vehicle is stationary. Otherwise, you could
damage the transmission.
X Stop the vehicle.
X Depress the clutch pedal fully.
X Shift to neutral N.
X Move the gear lever firmly to the left
beyond the point of resistance and thenforwards.
150Manual transmission
Driving and parking

iThe ECO start/stop function is not avail-
able when reverse gear is engaged.
Further information on the ECO start/stop function ( Ypage 144).
Shift recommendation
X
Shift gear according to gearshift recom- mendation :when shown in the multi-
function display of the instrument cluster.
The gearshift recommendations assist you in adopting an economical driving style. The rec- ommended gear is shown in the multifunction
display.
Automatic transmission
Important safety notes
GWARNING
If the engine speed is above the idling speed
and you engage transmission position Dor R,
the vehicle could pull away suddenly. There is a risk of an accident.
When engaging transmission position Dor R,
always firmly depress the brake pedal and do not simultaneously accelerate.
GWARNING
The automatic transmission switches to neu-
tral position Nwhen you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P. Prevent the parked vehi-
cle from rolling away by applying the parkingbrake.
Selector lever
Overview of transmission positions
Selector lever j
Park position with selector lever lock
kReverse gear
iNeutral
hDrive
Transmission position and drive pro-
gram display
:Transmission position display
;Drive program display
The current position of the selector lever is
shown by the indicators next to the selectorlever.
The indicators light up when the SmartKey is inserted into the ignition lock. The indicators go out when the SmartKey is removed from
the ignition lock.
Automatic transmission151
Driving and parking
Z