2012 MERCEDES-BENZ SLK-CLASS ROADSTER Owners Manual

As DISTRONIC PLUS transmits radar waves,
it can resemble the radar detectors of the
responsible authorities. You can refer to the
relevant chapter in the Operator's Manual if
questions are asked about this.
i USA only:
This device has been approved by the FCC
as a “Vehicular Radar System”. The radar
sensor is intended for use in an automotive
radar system only. Removal, tampering, or
altering of the device will void any
warranties, and is not permitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this
device could void the user’s authority to
operate the equipment.
i Canada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause interference,
and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the
device will void any warranties and is not
permitted. Do not tamper with, alter, or use
the device in any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.GWARNING
DISTRONIC PLUS distance is not a substitute
for the active intervention of the driver. It does
not detect pedestrians or stationary objects,
nor can it detect, recognize or predict the
road's course or the movements of vehicles
in front. DISTRONIC PLUS can only brake the
vehicle using 40% of the vehicle's maximum
available brake force.
DISTRONIC PLUS may not detect narrow
vehicles driving in front, e.g. motorcycles, or
vehicles driving in the lane beyond the lane
next to your vehicle, especially if the vehicles
are not driving on the middle of their lane.
The driver must always pay careful attention
to the road, weather and traffic conditions.
The driver must drive, steer and brake in a
manner which will allow him to always have
control of the vehicle.
Sources of high-frequency radio waves, such
as toll stations, speed-measuring radar, etc.,
can cause DISTRONIC PLUS to fail
temporarily.GWARNING
The DISTRONIC PLUS cannot take road and
traffic conditions into account. Only use the
DISTRONIC PLUS if the road, weather and
traffic conditions make it advisable to travel
at a constant speed.
GWARNING
Use of the DISTRONIC PLUS can be
dangerous on slippery roads. Rapid changes
in tire traction can result in wheel spin and
loss of control.
The DISTRONIC PLUS does not function in
adverse sight and distance conditions. Do not
use the DISTRONIC PLUS during conditions of
fog, heavy rain, snow or sleet.
GWARNING
The DISTRONIC PLUS cannot take weather
conditions into account. Switch off the
DISTRONIC PLUS or do not switch it on if:
R roads are slippery or covered with snow or
ice. The wheels could lose traction while
braking or accelerating, and the vehicle
could skid.
R the DISTRONIC PLUS system sensor covers
are dirty or visibility is diminished due to
snow, rain or fog, for example. The distance
control system functionality could be
impaired.
Always pay attention to surrounding traffic
conditions even while the DISTRONIC PLUS is
switched on. Otherwise, you may not be able
to recognize dangerous situations until it is
Driving systems159Driving and parkingZ

too late. This could cause an accident in which
you and/or others could be injured.GWARNING
The "Resume" function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
GWARNING
Your undivided attention to street and traffic
conditions is necessary at all times whether
DISTRONIC PLUS is active or not.
The use of DISTRONIC PLUS can be
dangerous on winding roads or in heavy traffic
because conditions do not allow safe driving
at a constant speed.
DISTRONIC PLUS does not react to stationary
objects on the road (for example, a vehicle
stopped in traffic or an abandoned vehicle).
DISTRONIC PLUS likewise does not react to
oncoming vehicles.
Deactivate DISTRONIC PLUS:
R when changing to the right lane, if the
vehicles in the left lane are driving slower
R when driving into a filter lane or an
expressway exit
R in complex driving situations, for example
in construction sites on an expressway
In these situations DISTRONIC PLUS will
maintain the set speed if it is not deactivated.
DISTRONIC PLUS is intended only for
maintaining a set speed and a set distance
from the objects moving in front of the
vehicle.
GWARNING
An intermittent warning sounds and the
distance warning lamp · in the instrument
cluster is illuminated if the DISTRONIC PLUS
system calculates that the distance to the
vehicle ahead and your vehicle's current
speed indicate that the DISTRONIC PLUS will
not be capable of slowing the vehicle
sufficiently to maintain the preset following
distance, which creates a danger of a
collision.
Immediately brake the vehicle to increase
your distance to the preceding vehicle. The
warning sound is intended as a final caution
in which you should intercede with your own
braking inputs to avoid a potentially
dangerous situation. Do not wait for the
operation of the warning signal to intercede
with your own braking. This will result in
potentially dangerous emergency braking
which will not always result in an impact being
avoided.
Tailgating increases the risk of an accident.GWARNING
DISTRONIC PLUS brakes your vehicle with a
maximum deceleration of 13 ft/s 2
(4 m/s 2
).
This corresponds to approximately 40% of
your vehicle's maximum braking force.
To avoid a collision, you must apply the brakes
yourself. DISTRONIC PLUS brakes the vehicle
just enough to restore the preset speed or the
preset distance to the vehicle in front.
GWARNING
If you do not receive visual or acoustic
warning signals during a critical traffic
situation, DISTRONIC PLUS has either not
recognized the collision risk, has been
deactivated or is malfunctioning.
Remember, whether or not DISTRONIC PLUS
is operating, it is ultimately always the drivers
responsibility to apply the brakes in order to
control the vehicle and avoid a collision.
160Driving systemsDriving and parking

Cruise control lever:To store the current speed or a higher
speed;To store the current speed or a lower
speed=To deactivate DISTRONIC PLUS?Storing the current speed or calling up the
last stored speedASetting the specified minimum distance
Switching on DISTRONIC PLUS, storing
and maintaining the current speed
Important safety notes
GWARNING
The vehicle can be braked when DISTRONIC
PLUS is activated. For this reason, deactivate
DISTRONIC PLUS if the vehicle is to be set in
motion by other means (e.g. in a car wash or
by towing).
In order to activate DISTRONIC PLUS, the
following conditions must be fulfilled:
R the engine must be started. It may take up
to two minutes after pulling away before
DISTRONIC PLUS is operational.
R the electric parking brake must be
released.
R ESP ®
must be active, but not intervening.
R the transmission must be in position D.
R the hood must be closed.
R the driver's door must be closed when you
shift from P to D or your seat belt must be
fastened.
R the front-passenger door must be closed.
R the vehicle must not skid.
Activating while driving
When driving at speeds below 20 mph
(30 km/h ), you can only activate DISTRONIC
PLUS if the vehicle in front has been detected
and is shown in the multifunction display. If
the vehicle in front is no longer detected and
displayed, DISTRONIC PLUS switches off and
a tone sounds.XBriefly pull the cruise control lever towards
you ?, or press it up : or down ;.
DISTRONIC PLUS is selected.XPress the cruise control lever repeatedly
up : or down ; until the desired speed
is set.XRemove your foot from the accelerator
pedal.
Your vehicle adapts its speed to that of the
vehicle in front, but only up to the desired
stored speed.
i If you do not fully release the accelerator
pedal, the DISTRONIC PLUS Passive
message appears in the multifunction
display. The set distance to a slower-
moving vehicle in front will then not be
maintained. You will be driving at the speed
you determine by the position of the
accelerator pedal.
Activating when driving towards a
stationary vehicle
If the vehicle in front of you is stationary, you
can only activate DISTRONIC PLUS once your
vehicle is stationary as well.
XBriefly pull the cruise control lever towards
you ?, or press it up : or down ;.
DISTRONIC PLUS is selected.
i DISTRONIC PLUS can only be activated at
under 20 mph ( 30km/h) if a vehicle in front
has been detected. Therefore, the
DISTRONIC PLUS distance display in the
instrument cluster should be activated
( Y page 190).
Driving systems161Driving and parkingZ

XPress the cruise control lever repeatedly
up : or down ; until the desired speed
is set.
i You can use the cruise control lever to set
the stored speed and the control on the
cruise control lever to set the specified
minimum distance ( Y page 164).
Pulling away
XIf the vehicle in front pulls away: remove
your foot from the brake pedal.XBriefly pull the cruise control lever towards
you ?.
or
XAccelerate briefly.
Your vehicle pulls away and adapts its
speed to that of the vehicle in front.
Driving
If there is no vehicle in front, DISTRONIC
PLUS operates in the same way as cruise
control.
If DISTRONIC PLUS detects that the vehicle
in front has slowed down, it brakes your
vehicle. In this way, the distance you have
selected is maintained.
If DISTRONIC PLUS detects that the vehicle
in front is driving faster, it accelerates your
vehicle, but only up to the speed you have
stored.
GWARNING
If you depress the brake, DISTRONIC PLUS is
deactivated unless your vehicle is stationary.
DISTRONIC PLUS then no longer brakes your
vehicle. In such cases, control the distance
from vehicles travelling in front with the brake
alone. You could otherwise cause an accident
and thereby injure yourself and others. The
driver remains fully responsible for the
vehicle's distance from other vehicles, the
speed being driven and for braking in good
time.
Changing lanes
If you change to the passing lane, DISTRONIC
PLUS supports you when:
R you are driving faster than 40mph
(60 km/h).
R DISTRONIC PLUS is maintaining the
distance to a vehicle in front.
R you switch on the appropriate turn signal.
R DISTRONIC PLUS does not detect a danger
of collision.
If these conditions are fulfilled, your vehicle
is accelerated. Acceleration will be
interrupted if changing lanes takes too long
or if the distance between your vehicle and
the vehicle in front becomes too small.
i When changing lanes, DISTRONIC PLUS
monitors the left lane on left-hand drive
vehicles and the right lane on right-hand
drive vehicles.GWARNING
DISTRONIC PLUS is only an aid designed to
assist driving.
It is not a substitute for attentive driving. The
driver remains fully responsible for the
vehicle's distance from other vehicles, the
vehicle's speed and for braking in good time.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
Stopping
GWARNING
Never get out of the vehicle when DISTRONIC
PLUS is activated.
DISTRONIC PLUS must also never be
operated, activated or deactivated by a
passenger or from outside the vehicle.
DISTRONIC PLUS does not replace the
electric parking brake and must not be used
for parking.
162Driving systemsDriving and parking

The DISTRONIC PLUS braking effect is
canceled and the vehicle can start moving if:
R DISTRONIC PLUS is deactivated using the
cruise control lever.
R you accelerate.
R there is a malfunction in the system or an
interruption in the power supply, e.g.
battery failure.
R the electrical system in the engine
compartment, the battery or the fuses are
tampered with.
R the battery is disconnected.
If you wish to leave the vehicle or park it,
deactivate DISTRONIC PLUS and secure the
vehicle against rolling away.
If DISTRONIC PLUS detects that the vehicle
in front is stopping, it brakes your vehicle until
it is stationary.
Once your vehicle is stationary, it remains
stationary and you do not need to depress the
brake.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
i Depending on the specified minimum
distance, your vehicle will come to a
standstill at a sufficient distance behind the
vehicle in front. The specified minimum
distance is set using the control on the
cruise control lever.
The electric parking brake automatically
secures the vehicle if DISTRONIC PLUS is
activated and:
R the driver's door is open and the driver's
seat belt is unfastened.
R the hood is opened.
R a system malfunction occurs.
R the power supply is not sufficient.
If there is a malfunction in the vehicle
electronics, a warning message may also
appear in the multifunction display.
Brake ImmediatelyXImmediately depress the brake pedal firmly
until the warning message in the
multifunction display goes out. DISTRONIC
PLUS is deactivated.
Shift to 'P'
XShift the transmission to position P to
prevent the vehicle from rolling away.
DISTRONIC PLUS is deactivated. The
warning message in the multifunction
display disappears.
The horn will also sound at regular intervals if
DISTRONIC PLUS is activated and you:
R switch the engine off, open the driver's
door and remove your seat belt
R open the hood
The sounding of the horn alerts you to the fact
that the vehicle has been parked while
DISTRONIC PLUS is still activated. The sound
becomes louder if you attempt to lock the
vehicle. The vehicle is not locked until
DISTRONIC PLUS is deactivated.
i If the engine has been switched off, it
cannot be started again until DISTRONIC
PLUS has been deactivated.
Setting a speed
GWARNING
Keep in mind that it may take a brief moment
until the vehicle has made the necessary
adjustments.
Increase or decrease the set vehicle speed to
a value that the prevailing road conditions and
legal speed limits permit. Otherwise, sudden
and unexpected acceleration or deceleration
of the vehicle could cause an accident and/
or serious injury to you and others.
XPress the cruise control lever up : for a
higher speed or down ; for a lower speed.XTo adjust the speed in 1 mph
increments (1 km/h increments): brieflyDriving systems163Driving and parkingZ

press the cruise control lever up : or
down ; to the pressure point.
The last speed stored is increased or
decreased every time the cruise control
lever is pushed up : or down ;.XTo adjust the speed in 5 mph
increments (10 km/h increments):
briefly press the cruise control lever
up : or down ; beyond the pressure
point.
The last speed stored is increased or
decreased every time the cruise control
lever is pushed up : or down ;.
i
DISTRONIC PLUS is not deactivated if you
depress the accelerator pedal. If you
accelerate to overtake, DISTRONIC PLUS
adjusts the vehicle's speed to the last
speed stored after you have finished
overtaking.
Storing the current speed or calling up
a stored speed
GWARNING
The set speed stored in memory should only
be set again if prevailing road conditions and
legal speed limits permit. Possible
acceleration or deceleration differences
arising from returning to the preset speed
could cause an accident and/or serious injury
to you and others.
XBriefly pull the cruise control lever towards
you ?.XRemove your foot from the accelerator
pedal.
DISTRONIC PLUS is activated. The first
time it is activated, the current speed is
stored. Otherwise, it sets the vehicle cruise
speed to the previously stored value.
Setting the specified minimum distance
You can set the specified minimum distance
for DISTRONIC PLUS by varying the time span
between one and two seconds. With this
function, you can set the minimum distance
that DISTRONIC PLUS keeps to the vehicle in
front, dependent on vehicle speed. You can
see this distance in the multifunction display
( Y page 165).GWARNING
It is up to the driver to exercise discretion to
select the appropriate setting given road
conditions, traffic, driver's preferred driving
style and applicable laws and driving
recommendations for safe following distance.
XTo increase: turn control ; in direction
= .
DISTRONIC PLUS then maintains a greater
distance between your vehicle and the
vehicle in front.XTo decrease: turn control ; in
direction :.
DISTRONIC PLUS then maintains a shorter
distance between your vehicle and the
vehicle in front.
i Make sure that you maintain a sufficiently
safe distance from the vehicle in front.
Adjust the distance to the vehicle in front if
necessary.
164Driving systemsDriving and parking

DISTRONIC PLUS displays in the
speedometer
When DISTRONIC PLUS is activated, one or
two segments ; in the set speed range light
up.
i For design reasons, the speed displayed
in the speedometer may differ slightly from
the speed set for DISTRONIC PLUS.
If DISTRONIC PLUS detects a vehicle in front,
segments ; between speed of the vehicle in
front : and stored speed = light up.
DISTRONIC PLUS displays in the
multifunction display
General notes
You can select the distance display in the
Assistance menu ( Y page 190) of the on-
board computer.
Display when DISTRONIC PLUS is
deactivated
XSelect the Distance Display function
using the on-board computer
( Y page 190).
When DISTRONIC PLUS is deactivated, you
will see the following in the multifunction
display:
:Symbol for activated PRE-SAFE ®
Brake;Vehicle in front, if detected=Distance indicator, current distance to
the vehicle in front?Specified minimum distance to the
vehicle in front; adjustableAOwn vehicle
Display when DISTRONIC PLUS is
activated
XSelect the Distance Display function
using the on-board computer
( Y page 190).
You will see the stored speed for about five
seconds when you activate DISTRONIC PLUS.
After this time, you will see the following in
the multifunction display while DISTRONIC
PLUS is activated:
:DISTRONIC PLUS activated;Own vehicle=Specified minimum distance to the
vehicle in front; adjustable?Vehicle in front, if detectedDriving systems165Driving and parkingZ

Deactivating DISTRONIC PLUS
There are several ways to deactivate
DISTRONIC PLUS:
XBriefly press the cruise control lever
forwards :.
or
XBrake, unless the vehicle is stationary.
When you deactivate DISTRONIC PLUS, the
DISTRONIC PLUS Off message is shown in
the multifunction display for approximately
five seconds.
i The last speed stored remains stored until
you switch off the engine.
DISTRONIC PLUS is automatically
deactivated if:
R you engage the electric parking brake or if
the vehicle is automatically secured with
the electric parking brake
R you are driving slower than 15 mph
(25km/h) and there is no vehicle in front,
or if the vehicle in front is no longer
detected.
R ESP ®
intervenes or you deactivate ESP ®
.
R the transmission is in the P, R or N position.
R you switch off the radar sensor system
( Y page 194).
R you pull the cruise control lever towards
you in order to pull away and the front-
passenger door is open.
R the vehicle has skidded.
If DISTRONIC PLUS is deactivated, you will
hear a warning tone. The DISTRONIC PLUS
Off message is shown in the multifunction
display for approximately five seconds.GWARNING
DISTRONIC PLUS is deactivated and releases
the brakes if the vehicle is slowed down to a
speed below 20 mph ( 30km/h) by the system,
provided that DISTRONIC PLUS does not
detect a vehicle directly in front. At this point,
the driver must apply the brakes in order to
slow down further and bring the vehicle to a
standstill.
Tips for driving with DISTRONIC PLUS
Important safety notes
The following contains descriptions of certain
road and traffic conditions in which you must
be particularly attentive. In such situations,
brake if necessary. DISTRONIC PLUS is then
deactivated.
GWARNING
The DISTRONIC PLUS works to maintain the
speed selected by the driver unless a moving
obstacle proceeding directly ahead of it in the
same travel direction is detected (e.g.
following another vehicle ahead of you at your
set distance).
This means that:
R Your vehicle can pass another vehicle after
you have changed lanes.
R While in a sharp turn or if the preceding
vehicle is in a sharp turn, the DISTRONIC
PLUS could lose sight of the preceding
vehicle. Your vehicle could then accelerate
to the previously selected speed.
The DISTRONIC PLUS regulates only the
distance between your vehicle and those
directly ahead of it. It may not register
stationary objects in the road, e.g.:
R a stopped vehicle in a traffic jam
R a disabled vehicle
R an oncoming vehicle
166Driving systemsDriving and parking