238 Controls in detailDriving systemsThe driving systems of your vehicle are de-
scribed on the following pages:
Cruise control, with which the vehicle
can maintain a preset speed.
Downhill Speed Regulation (DSR),
which supports you when you are
driving downhill.
Off-road driving program, which
supports you when you are driving
off-road.
Air suspension package* which adjusts
the vehicle suspension characteristics
automatically and controls the vehicle
level.
Parktronic*, which serves as a parking
aid.
For information on the ABS, BAS, EBB,
ESP®, and 4-ETS driving systems, see
“Driving safety systems” (
page 93).
Cruise control
The cruise control automatically maintains
the speed you set for your vehicle.
Use of cruise control is recommended for
driving at a constant speed for extended
periods of time. You can set or resume
cruise control at any speed above
20 mph (30 km/h).
The cruise control function is operated by
means of the cruise control lever.
The cruise control lever is the uppermost
lever on the left-hand side of the steering
column (
page 22).
iThe cruise control should not be acti-
vated during off-road driving.
Warning!
G
The cruise control is a convenience system
designed to assist the driver during vehicle
operation. The driver is and must remain at
all times responsible for the vehicle speed
and for safe brake operation.
Only use the cruise control if the road,
traffic, and weather conditions make it ad-
visable to travel at a steady speed.
The use of cruise control can be danger-
ous on winding roads or in heavy traffic
because conditions do not allow safe
driving at a steady speed.
The use of cruise control can be danger-
ous on slippery roads. Rapid changes in
tire traction can result in wheel spin and
loss of control.
Deactivate the cruise control when driv-
ing in fog.
The “Resume” function should only be oper-
ated if the driver is fully aware of the previ-
ously set speed and wishes to resume this
particular preset speed.
240 Controls in detailDriving systems
Canceling cruise control
There are several ways to cancel the cruise
control:
Step on the brake pedal.
The cruise control is canceled. The last
speed set is stored for later use.
or
Briefly push the cruise control lever in
direction of arrow3 (
page 239).
The cruise control is canceled. The last
speed set is stored for later use.
iOn uphill grades, the cruise control
may not be able to maintain the set
speed. Once the grade eases, the set
speed will be resumed.
On downhill grades, the cruise control
maintains the set speed with braking
from the vehicle’s braking system. In
addition, on longer downhill grades the
automatic transmission will automati-
cally downshift.
iThe last stored speed is canceled when
you turn off the engine.
iThe cruise control switches off auto-
matically when
you step on the brake pedal
you depress the parking brake
pedal
The cruise control also switches off au-
tomatically when
the vehicle speed is below 20 mph
(30 km/h)
the ESP
® is in operation or
switched off with the ESP
® switch
(
page 97)
you set the automatic transmission
toN while driving
An acoustic warning sounds and the
message
Cruise control OFF
appears
in the multifunction display.
254 Controls in detailDriving systemsWhen the highway/high-speed level is
reached, the following message appears in
the multifunction display for five seconds:
Indicator lamp2 (
page 252) goes out.The following applies additionally when
towing a trailer:
The vehicle is lowered to the highway
level when it reaches a speed of 5 mph
(8 km/h).
The high-speed level is not available.
The restrictions that apply to towing
also apply when using accessories that
are connected to the trailer power
socket, such as an accessory bicycle
rack.
Parktronic* system (Parking assist)
iThe vehicle is lowered to the highway
level if:
the vehicle speed is above 55 mph
(88 km/h)
the speed stays between 40 mph
(64km/h) and 55mph (88km/h)
for approximately 20 seconds
iDepending on the ADS setting
(page 249), the vehicle will be low-
ered to the high-speed level when trav-
eling at higher speeds. At speeds below
40 mph (64 km/h) at the latest, it will
be returned to the highway level.
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 rests with the driver.
Special attention must be paid to objects
with smooth surfaces or low silhouettes
(e.g. trailer couplings, painted posts, 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, es-
pecially at times of snow and ice. See
“Cleaning the Parktronic system sensors”
(page 377).
Interference 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.
255 Controls in detail
Driving systems
The Parktronic system is an electronic
parking aid and designed to assist the
driver during parking maneuvers. It visually
and audibly indicates the relative distance
between the vehicle and an obstacle.
The Parktronic system is automatically
activated when you switch on the ignition,
release the parking brake, and set the
automatic transmission toD,R, orN.
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
toP or depress the parking brake pedal.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
Range of the sensors
To function properly, the sensors must be
free of dirt, ice, snow and slush. Clean the
sensors regularly, being careful not to
scratch or damaging the sensors, see
“Cleaning the Parktronic* system sensors”
(
page 377).
Warning!
G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.
256 Controls in detailDriving systemsFront 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.
Warning 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 located in the rear
passenger compartment in the roof dome.
Front area warning indicator1Left side of the vehicle
2Right side of the vehicle
3Readiness indicators
Each warning indicator is divided into five
yellow and two red segments for either
side of the vehicle. The Parktronic system
is operational when the readiness
indicators3 are illuminated.
The position of the automatic transmission
determines which warning indicator will be
activated.
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. working jackhammers, car
wash or the air brakes of trucks) may
impair the operation of the Parktronic
system.
Center
approx. 8 in (20 cm)
Corners
approx. 6 in (15 cm)
257 Controls in detail
Driving systems
As your vehicle approaches an object, one
or more distance segments will come on,
depending on the distance. When the
second red 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 segment. The signal is
canceled when the automatic trans-
mission is set toP, or the parking brake
is activated.
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 segment. The signal is
canceled when the automatic trans-
mission is set toD, P, or the parking
brake is activated.
Switching Parktronic* system on/off
The Parktronic system can be switched off
manually using the control system
(
page 175).
As your vehicle approaches an object, and
three or more distance segments will
come on, the following message appears in
the multifunction display.
Pressæ orç to switch function
off.
Automatic trans-
mission position
Warning indicator
D
Front area activated
R or N
Front and rear area
activated
P
Neither activated
iThe display disappears automatically
within ten seconds if you continue to
approach an object.
If the vehicle comes closer to the ob-
ject and the first red distance segment
comes on, the display appears continu-
ously. It disappears if:
you clear the message by pressing
theèÿkor
buttonj on the multifunction
steering wheel
or
the distance is increased and the
third yellow distance segment goes
out.
300 OperationDriving instructionsBrakesTo 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.
If the parking brake is released and the
brake warning lamp in the instrument clus-
ter stays on and there is no audible warn-
ing (EBP), the brake fluid level in the
reservoir is too low.Brake pad wear or a leak in the system may
be the reason for low brake fluid in the
reservoir.
Have the brake system inspected immedi-
ately. Contact an authorized
Mercedes-Benz Light Truck Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Light Truck Center.
Only install brake pads and brake fluid
recommended by Mercedes-Benz.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 ef-
fect. 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 acci-
dent.
!Be very careful not to endanger other
road users when you apply the brakes.
Refer to the description of the Brake
Assist System (BAS) (
page 95).
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.
301 Operation
Driving instructions
After hard braking, it is advisable to drive
on for some time, rather than immediately
park, so that the air stream will 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.When starting 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 Warranty.
Parking
!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.
!Simultaneously depressing the
accelerator pedal and applying the
brake reduces engine performance and
causes premature brake and drivetrain
wear.!Set the parking brake whenever park-
ing or leaving the vehicle. In addition,
move gear selector lever to positionP.
When parking on hills, always turn front
wheels towards the curb.
Warning!
G
To reduce the risk of personal injury, or
damage to the vehicle powertrain, as a
result of vehicle/ trailer movement, before
turning off the engine and leaving the vehi-
cle always:
Keep right foot on brake pedal.
Firmly depress parking brake pedal.
Shift the automatic transmission to
positionP.
Slowly release brake pedal and let vehi-
cle and trailer roll into chocks until
stopped.
When parked on an incline, turn front
wheel towards the road curb.
Have a second person place wheel
chocks on downhill side of left and right
trailer wheels.