420 Controls in detail
Driving systems
StoppingWhen DISTRONIC Plus detects that the ve-
hicle in front of you is stopping, the vehicle
brakes until it also stops.
Once DISTRONIC Plus has stopped your
vehicle and it is at a standstill, it remains
stationary; the brake pedal does not need
to be depressed.
Warning!G
DISTRONIC Plus’s braking effect is canceled
and the vehicle can start to roll if
DISTRONIC Plus is switched off using
the DISTRONIC Plus lever
you accelerate
the system or the power supply is mal-
functioning, e.g. due to battery failure
the electrical components in the engine
compartment or the fuses have been
manipulated
the battery is disconnected
Warning!G
Never get out of the vehicle while
DISTRONIC Plus is switched on!
DISTRONIC Plus must never be operated or
switched off by passengers or from outside
the vehicle.
DISTRONIC Plus is not a substitute for the
electronic parking brake and may not be
used for parking.
When you get out of the vehicle or switch off
the engine, deactivate DISTRONIC Plus and
secure the vehicle from rolling away by en-
gaging the electronic parking brake.
iAfter a short while, your vehicle is secured in
place by the electronic parking brake so that the
operating brake can be relieved of load.
iDepending on the following distance set us-
ing the distance setting switch on the DISTRON-
IC Plus lever, your vehicle will stop
approximately 13.1 ft away from the vehicle in
front of you.
424 Controls in detail
Driving systems
DISTRONIC Plus deactivates automatically
when:
the vehicle is secured with the elec-
tronic parking brake
the vehicle speed is below 20 mph
(30 km/h) and no preceding vehicle is
detected
the ESP® is in operation or switched off
with the ESP® switch (page 71)
you set the automatic transmission
toP, R, or N while driving
the radar sensors are switched off
(
page 272)
the vehicle rolls backward
The segments in the multifunction display
go out, an acoustic signal sounds, and the
message “DISTRONIC PLUS Off” appears in
the multifunction display for approximately
5 seconds.If the vehicle has been stopped by
DISTRONIC Plus and a malfunction occurs
in the system, the message “Brake immedi-
ately” will appear on the multifunction dis-
play. Step on the brake immediately to
prevent the vehicle from rolling.
DISTRONIC Plus is then switched off and
the message disappears.
Warning!G
DISTRONIC Plus switches off and releases
the brakes when the vehicle decelerates be-
low the minimum speed of 20 mph
(30 km/h) by operation of the system un-
less DISTRONIC Plus detects a vehicle di-
rectly ahead of you. At that time the driver
must apply the brakes in order to reduce ve-
hicle speed further or bring it to a stop.
!Setting the automatic transmission toN
while driving cancels the DISTRONIC Plus. How-
ever, the automatic transmission should not be
set toN while driving except to coast when the
vehicle is in danger of skidding (e.g. on icy
roads).
iDepressing the accelerator pedal does not
deactivate DISTRONIC Plus. After brief accelera-
tion (e.g. for passing), DISTRONIC Plus will re-
sume to the last set speed.
431 Controls in detail
Driving systems
Parktronic system*
The Parktronic system is an electronic
parking aid with ultrasonic sensors that
helps you while parking.
It visually and audibly indicates the relative
distance between the vehicle and an ob-
stacle.
The Parktronic system is automatically ac-
tivated when you switch on the ignition, re-
lease the electronic parking brake or start
the engine and engage gear D, R or N.The Parktronic system deactivates at
speeds over approximately 11 mph
(18 km/h). At lower speeds the Parktronic
system turns on again.
The Parktronic system also deactivates
when you set the automatic transmission
to P or secure the vehicle in place with the
electronic parking brake and switch off the
engine.
The Parktronic system monitors the sur-
roundings of your vehicle with six sensors
in the front bumper and four sensors in the
rear bumper.
1Sensors in the front bumper (Only visi-
ble without DISTRONIC Plus*)
Warning!G
Parktronic is a supplemental system. It is
not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always remains with the driver.
Warning!G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.
!Special attention must be paid to objects
with smooth surfaces or low silhouettes (e.g.
trailer couplings, painted posts, elevated cross-
bars or road curbs). Such objects may not be
detected by the system and can damage the
vehicle.
!The operational function of the Parktronic
system can be affected by dirty sensors, espe-
cially at times of snow and ice.
Make sure that the area on the bumpers around
the sensors is free of dirt, ice and/or slush,
otherwise the Parktronic system may not
function properly, see “Cleaning the Parktronic*
system sensors” (
page 559).
iInterference caused by other ultrasonic sig-
nals (e.g. working jackhammers, car wash, or the
air brakes of trucks) can cause the system to
send erratic indications, and should be taken
into consideration.
432 Controls in detail
Driving systems
Range of the sensorsFront 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.
iTo function properly, the sensors must be
free of dirt, ice, snow and slush. Clean the sen-
sors regularly, being careful not to scratch or
damage the sensors, see “Cleaning the Park-
tronic* system sensors” (
page 559).
Centerapprox. 40 in (100 cm)
Cornersapprox. 24 in (60 cm)
Centerapprox. 48 in (120 cm)
Cornersapprox. 32 in (80 cm)
!During parking maneuvers, pay special at-
tention to objects located above or below the
height of the sensors (e.g. street curbs, painted
posts, or trailer hitches etc.). The Parktronic sys-
tem will not detect such objects at close range
and damage to your vehicle or the object may
result.
Ultrasonic signals from outside sources (e.g.
truck air brakes, car wash, or jackhammers) may
impair the operation of the Parktronic system.
Centerapprox. 8 in (20 cm)
Cornersapprox. 6 in (15 cm)
500 Operation
Driving instructions
Brakes
To help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only sub-
jected to moderate loads, you should occa-
sionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads.Refer to the description of the Brake Assist
System (BAS or BAS Plus*) (
page 66).
Brake pad wear or a leak in the system may
be the reason for low brake fluid level in
the reservoir.
The brake fluid level in the reservoir may
be too low if the red brake warning lamp in
the instrument cluster comes on while the
engine is running and an acoustic warning
sounds (
page 569). Observe additional
messages in the multifunction display that
may appear (
page 580).
Have the brake system inspected
immediately. Contact an authorized
Mercedes-Benz Center.
Warning!G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat
reduced and increased pedal pressure may
be necessary to obtain expected braking
effect. Maintain a safe distance from
vehicles in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating,
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an
accident.
!Because the ESP® operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position0 or1 or
KEYLESS-GO start/stop button* in position0
or1) when
the electronic parking brake is being tested
on a brake test dynamometer
the vehicle is being towed with the
front/rear axle raised
Active braking action through the ESP
® may oth-
erwise seriously damage the brake system.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking ma-
neuvers.
501 Operation
Driving instructions
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Center.
Only install brake pads and brake fluid
recommended by Mercedes-Benz.
After hard braking, it is advisable to drive
on for some time, rather than immediately
park, so that the air stream can cool down
the brakes faster.Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.
Warning!G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.
!When driving down long and steep grades,
relieve the load on the brakes by shifting into a
lower gear to use the engine’s braking power.
This helps prevent overheating of the brakes and
reduces brake pad wear.
When using the engine’s braking power, a drive
wheel may not spin for an extended period of
time, e.g. on slippery road surfaces.
This may cause serious damage to the drivetrain
which is not covered by the Mercedes-Benz Lim-
ited Warranty.
!When driving off on a slippery surface, do
not allow a drive wheel to spin for an extended
period with the ESP
® switched off. Doing so may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited War-
ranty.
!Simultaneously depressing the accelerator
pedal and applying the brakes reduces engine
performance and causes premature brake wear
and drivetrain wear.
503 Operation
Driving instructions
Specified tire inflation pressures must be
maintained. This applies particularly if the
tires are subject to extreme operating con-
ditions (e.g. high speeds, heavy loads, high
ambient temperatures).
For more information, see “Tires and
wheels” (
page 520).
Hydroplaning
Depending on the depth of the water layer
on the road, hydroplaning may occur, even
at low speeds and with new tires. Reduce
vehicle speed, avoid track grooves in the
road and apply brakes cautiously in the
rain.
Tire traction
The safe speed on a wet, snow covered or
icy road is always lower than on a dry road.
You should pay particular attention to the
condition of the road whenever the outside
temperatures are close to the freezing
point.Mercedes-Benz recommends winter tires
(
page 549) with a minimum tread depth
of approximately 1/6in (4 mm) on all four
wheels for the winter season to ensure
normal balanced handling characteristics.
On packed snow, they can reduce your
stopping distance compared to summer
tires.
Stopping distance, however, is still consid-
erably greater than when the road is not
covered with snow or ice. Exercise appro-
priate caution.
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire or driving at high
speed with a flat tire will cause excessive
heat build-up and possibly a fire.
Warning!G
If ice has formed on the road, tire traction
will be substantially reduced. Under such
weather conditions, drive, steer and brake
with extreme caution.
!Avoid spinning of a drive wheel. This may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited War-
ranty.
520 Operation
Tires and wheels
Contact an authorized Mercedes-Benz
Center for information on tested and
recommended rims and tires for summer
and winter operation. They can also offer
advice concerning tire service and
purchase.Important guidelines
Only use sets of tires and rims of the
same type and make.
Tires must be of the correct size for the
rim.
Break in new tires for approximately
60 miles (100 km) at moderate
speeds.
Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire inflation pressure loss and
damage to the tire beads.
If vehicle is heavily loaded, check tire
inflation pressure and correct as
required.
Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths of less than
1/8in (3 mm).
When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:
The wheel brakes or suspension
components can be damaged.
The operating clearance of the wheels
and the tires may no longer be correct.
Warning!G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can
result in the bolts loosening and possibly an
accident.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on re-
treads. The operating safety of the vehicle
cannot be assured when such tires are used.