261 Controls in detail
Driving systems
Front sensors
Rear sensorsMinimum distance
If the system detects an obstacle in this
range, all the distance warning segments
illuminate and you hear a warning signal. If
the obstacle is closer than the minimum
distance, the actual distance may no long-
er be indicated by the system.Center
approx. 40 in (100 cm)
Corners
approx. 24 in (60 cm)
Center
approx. 48 in (120 cm)
Corners
approx. 32 in (80 cm)
!During parking maneuvers, pay special
attention to objects located above or
below the height of the sensors (e.g.
planters or trailer hitches). The
Parktronic system will not detect such
objects at close range and damage to
your vehicle or the object may result.
Ultrasonic signals from outside sourc-
es (e.g. truck air brakes, car wash, or
jackhammers) may impair the opera-
tion of the Parktronic system.
Center
approx. 8 in (20 cm)
Corners
approx. 6 in (15 cm)
262 Controls in detailDriving systemsWarning indicators
Visual signals indicate to the driver the rel-
ative distance between the sensors and an
obstacle. The warning indicator for the
front area is located above the center air
vents in the dashboard. The warning indi-
cator for the rear area is integrated be-
tween the rear backrests.
1Left side of the vehicle
2Right side of the vehicle
Each warning indicator is divided into six
yellow and two red distance segments for
either side of the vehicle. The Parktronic
system is ready when the border around
the indicator is illuminated.The position of the gear selector lever de-
termines which warning indicators will be
activated.As your vehicle approaches an object, one
or more distance segments will illuminate,
depending on the distance. When the
eighth distance segment illuminates, you
have reached the minimum distance.
Front area: An intermittent acoustic
warning will sound as the first red dis-
tance segment illuminates and a con-
stant acoustic warning lasting a
maximum of two seconds will sound for
the second red distance segment. The
signal is canceled when the gear selec-
tor lever is placed in positionP.
Rear area: An intermittent acoustic
warning will sound as the first red dis-
tance segment illuminates and a con-
stant acoustic warning lasting a
maximum of two seconds will sound for
the second red distance segment. The
signal is canceled when the gear selec-
tor lever is placed in position DorP.
Gear selector le-
ver position
Warning indicator
D
Front area activated
R or N
Front and rear area
activated
P
Neither activated
263 Controls in detail
Driving systems
Switching the Parktronic system
on/off
The Parktronic system can be switched off
manually.
The Parktronic switch is located in the up-
per part of the center console (
page 27).
1Parktronic switch
2Indicator lamp
Switching off the Parktronic system
Press Parktronic switch1.
Indicator lamp2 comes on.Switching on the Parktronic system
Press Parktronic switch1 again.
Indicator lamp2 goes out.
Parktronic system malfunction
If only the red distance segments illumi-
nate and an acoustic warning sounds,
there is a malfunction in the Parktronic
system. The Parktronic system will auto-
matically switch off after 20 seconds and
the indicator lamp in the Parktronic switch
comes on.
Have the Parktronic system checked
by an authorized Mercedes-Benz
Center as soon as possible.If only the red distance segments illumi-
nate and no acoustic warning sounds, the
Parktronic system sensors are dirty or
there is an interference from other radio or
ultrasonic signals. The Parktronic system
will automatically switch off after 20 sec-
onds and the indicator lamp in the Park-
tronic switch comes on.
Switch off the ignition.
Clean the Parktronic system sensors
(page 349).
Switch on the ignition.
or
Check the Parktronic system operation
at another location to rule out interfer-
ence from outside radio or ultrasonic
signals.
iThe Parktronic system is automatically
switched on when the ignition is
switched on (
page 36).
300 OperationDriving instructionsCatalytic converter
Your Mercedes-Benz is equipped with
monolithic-type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial con-
trol of the pollutants in the exhaust emis-
sions. Keep your vehicle in proper
operating condition by following our
recommended maintenance instructions
as outlined in your Maintenance Booklet.
Emission control
Certain systems of the engine serve to
keep the toxic components of the exhaust
gases within permissible limits required by
law.
These systems, of course, will function
properly only when maintained strictly ac-
cording to factory specifications. Any ad-
justments to the engine should therefore
be carried out only by qualified
Mercedes-Benz Center authorized techni-
cians.
Engine adjustments should not be altered
in any way. Moreover, the specified service
jobs must be carried out regularly accord-
ing to Mercedes-Benz servicing require-
ments. For details refer to the
Maintenance Booklet.
!To prevent damage to the catalytic
converters, only use premium unleaded
gasoline in this vehicle.
Any noticeable irregularities in engine
operation should be repaired promptly.
Otherwise, excessive unburned fuel
may reach the catalytic converter,
causing it to overheat and potentially
start a fire.
Warning!
G
As with any vehicle, do not idle, park or op-
erate this vehicle in areas where combusti-
ble materials such as grass, hay, or leaves
can come into contact with the hot exhaust
system, as these materials could be ignited
and cause a vehicle fire.
349 Operation
Vehicle care
Cleaning the Parktronic system*
sensors
1Parktronic system* sensors
Clean the sensors1 on the bumpers
using a mild car wash detergent, such
as Mercedes-Benz approved Car Sham-
poo, with plenty of water and a soft,
non-scratchy cloth.
When using a steam cleaner or power
washer, aim nozzle only briefly from a min-
imum distance of 12 in (30 cm) at
sensors1.Do not apply strong pressure to the sensor
cover, applying strong pressure may dam-
age the sensor cover.
To prevent scratches, never apply strong
force and only use a soft, non-scratchy
cloth when cleaning the sensor. Do not at-
tempt to wipe dirty sensors with a dry cloth
or sponge.Wiper blades
Fold wiper arm forward until it snapes
into place.
Clean the wiper blade inserts with a
clean cloth and detergent solution.Warning!
G
For safety reasons, switch off wipers and
remove SmartKey from starter switch
(vehicles with KEYLESS-GO*: make sure the
vehicle's on-board electronics have status 0) before cleaning the wiper blades.
Otherwise, the wiper motor could suddenly
turn on and cause injury. !Fold the windshield wiper arms back
onto the windshield before turning the
SmartKey in the starter switch.
Hold onto the wiper when folding the
wiper arm back. If released, the force
of the impact from the tensioning
spring could crack the windshield.
384 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
.
High beam, left
The left high beam lamp is malfunction-
ing.
Replace the bulb as soon as possible.
High beam, right
The right high beam lamp is malfunction-
ing.
Replace the bulb as soon as possible.
Lamp sensor
Drive to workshop
The lamp sensor is malfunctioning. The
headlamps switch on automatically.
In the control system, set lamp opera-
tion to manual (
page 152).
Switch on headlamps using the exteri-
or lamp switch.
Visit an authorized Mercedes-Benz
Center as soon as possible.
License plate lamp,
left
The left license plate lamp is malfunction-
ing.
Replace the bulb as soon as possible.
License plate lamp,
right
The right license plate lamp is malfunc-
tioning.
Replace the bulb as soon as possible.
Low beam, left
The left low beam lamp is malfunctioning.
Halogen headlamp:
Replace the bulb as soon as possible.
Bi-Xenon* headlamp:
Visit an authorized Mercedes-Benz
Center as soon as possible.
464 Technical termsMultifunction steering wheel
Steering wheel with buttons for operat-
ing the control system.
Normal occupant weight
(
page 337)
OCS
(Occupant C
lassification S
ystem)
The system automatically turns the
front passenger front air bag on or off
based on the classified occupant size
category determined by weight sensor
readings from the seat.
Overspeed range
Engine speeds within the red marking
on the tachometer dial. Avoid this en-
gine speed range, as it may result in se-
rious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.
Parktronic (Parking assist)*
System which uses visual and acoustic
signals to assist the driver during
parking maneuvers.Poly-V-belt drive
Drives engine-components (alternator,
AC compressor, etc.) from the engine.
Power train
Collective term designating all
components used to generate and
transmit motive power to the drive
axles, including
engine
clutch/torque converter
transmission
transfer case
drive shaft
differential
axle shafts/axles
Production options weight
(
page 337)Program mode selector switch
Used to switch the automatic transmis-
sion between regular operationS and
comfort operationC.
CLK 55 AMG with steering wheel gear-
shift control and manual shift program:
In addition toS andC (for regularS or
comfortC operation, see above) you
can use theM for manual shift
program.
PSI
(P
ounds per S
quare I
nch)
(
page 337)
Recommended tire inflation pressure
(page 337)
REST
(Residual engine heat utilization)
Feature that uses the engine heat
stored in the coolant to heat the vehi-
cle interior for a short time after the en-
gine has been turned off.
465 Technical terms
Restraint systems
Seat belts, child restraints, lower an-
chors and tethers for children (LATCH).
As independent systems, their protec-
tive functions complement one anoth-
er.
Rim
(
page 337)
Roll bars
Occupant protection system which
consists of tubular steel, integrated in
the rear head restraints. The roll bars
are lowered into the car body during
normal driving conditions and raised
automatically in an accident or in a crit-
ical driving situation.RON
(R
esearch O
ctane N
umber)
The Research Octane Number for gaso-
line as determined by a standardized
method. It is an indication of a gaso-
line's ability to resist undesired detona-
tion (knocking). The average of both
the ->MON (Motor Octane Number)
and RON (Research Octane Number) is
posted at the pump, also known as
ANTI-KNOCK INDEX.
Shift lock
When the vehicle is parked, this lock
prevents the gear selector lever from
being inadvertently moved out of
positionP without SmartKey turned
and brake pedal depressed.
Sidewall
(
page 337)Soft top
Soft top roof that can be opened by
pulling and closed by pressing a switch
and stored in the soft top compartment
in the trunk area.
Speedshift (CLK 500, CLK 55 AMG)
Steering wheel gearshift control. You
can change the gears yourself with the
steering wheel gearshift buttons.
SRS
(S
upplemental R
estraint S
ystem)
Air bags, air bag control unit (with
crash sensor), emergency tensioning
device. Though independent systems,
they are closely interfaced to provide
effective occupant protection.