2008 MERCEDES-BENZ ML320 brakes

190 Controls in detail
Automatic transmission
Driving tips
Accelerator position
Your driving style influences the
transmission’s shifting behavior:
Less throttle Earlier upshifting
More throttle Later upshifting
Kickdown
Use kickdown when you want maximum
acceleration.
Press the accelerator past the point of
resistance.
Depending on the engine speed the
transmission shifts into a lower gear.
Ease on the accelerator when you have
reached the desired speed.
The transmission shifts up again.Stopping
When you stop briefly, e.g. at traffic lights:
Leave the transmission in gear.
Hold the vehicle with the brake.
When you stop for a longer period of time
with the engine idling and/or on a hill:
Set the parking brake.
Shift into park positionP.
Maneuvering
When you maneuver in tight areas,
e.g. when pulling into a parking space:
Control the vehicle speed by gradually
releasing the brakes.
Accelerate gently.
Never abruptly step on the accelerator.
Warning!G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. Children could shift the
automatic transmission out of park
positionP, which could result in an accident
and/or serious personal injury.

245 Controls in detail
Driving systems
1Setting current or higher speed
Adjustment in 1 mph increments (to
the resistance point) or 5 mph
increments (past the resistance point)
(Canada: 1 km/h or 10 km/h)
2Setting current or lower speed
Adjustment in 1 mph increments (to
the resistance point) or 5 mph
increments (past the resistance point)
(Canada: 1 km/h or 10 km/h)
3Canceling cruise control
4Resume to last set speed
Warning!G
The cruise control is a convenience system
designed to assist the driver during vehicle
operation. The driver is and must always
remain responsible for the vehicle’s speed
and for safe brake operation.
Only use the cruise control if the road, traffic
and weather conditions make it advisable to
travel at a constant speed.

The use of the cruise control can be
dangerous on winding roads or in heavy
traffic because conditions do not allow
safe driving at a constant speed.

The use of the cruise control can be
dangerous on slippery roads. Rapid
changes in tire traction can result in
wheel spin and loss of control.

Deactivate the cruise control when
driving in fog.
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.
Warning!G
The cruise control brakes automatically so
that the set speed is not exceeded. The
brake pedal depresses when the cruise con-
trol engages the brakes.
Keep driver’s foot area clear at all times,
including the area under the brake pedal.
Objects stored in this area may impair pedal
movement which could interfere with the
braking ability of the cruise control system.
Do not place your foot under the brake pedal
– your foot could become caught.
Keep in mind that the cruise control is a
convenience system designed to assist the
driver during vehicle operation. The driver is
and must always remain responsible for the
vehicle’s speed and for safe brake
operation.

249 Controls in detail
Driving systems
Setting to last stored speed
(“Resume” function)
Briefly pull the cruise control lever in di-
rection of arrow4 (
page 245).
The cruise control resumes to the last
set speed, or if no speed is stored, it
will set and store the current speed.
Remove your foot from the accelerator
pedal.
The last set speed appears in the multi-
function display for approximately
5seconds.
Downhill Speed Regulation (DSR)For more information, see “Off-road driv-
ing” (
page 319).
The DSR is an aid for driving downhill. DSR
regulates your vehicle’s speed when driv-
ing downhill to the value set in the control
system (
page 178). The steeper the
downhill gradient is, the greater the brake
application. On flat road surfaces, DSR
brakes only slightly or not at all.
DSR regulates the vehicle’s speed in auto-
matic transmission positionsD, orR.
You can drive slower or faster than the set
speed at any time by braking the vehicle or
depressing the accelerator pedal.
Warning!G
The set speed stored in memory should only
be set again if prevailing road conditions
permit. Possible acceleration or decelera-
tion differences arising from returning to the
preset speed could cause an accident
and/or serious injury to you and others.
Warning!G
Downhill Speed Regulation is a convenience
system designed to assist the driver during
vehicle operation. The system must be set
to be appropriate for the topographical and
weather conditions encountered which can
change quickly. The driver is and must
remain at all times responsible for the vehi-
cle speed and for safe brake operation.
Depending on the programmed speed
(
page 178), actual vehicle speed and gra-
dient, switching on the DSR while driving
can cause the vehicle to slow down rapidly
and you may hear a sound which is caused
by the activation of the vehicle’s brake sys-
tem through the DSR. Sudden and unex-
pected deceleration can result in loss of
vehicle control, causing an accident and/or
serious personal injury to you and others.
Do not switch on the DSR in a circumstance
where rapid deceleration could result in a
loss of vehicle control.
iIn addition, make use of the engine’s braking
effect by shifting the automatic transmission
into a lower gear.

250 Controls in detail
Driving systems
Switching the Downhill Speed
Regulation on/off
The switch is located on the upper part of
the center console.
1DSR on/off
2Indicator lampiWhenever DSR is switched on, DSR will use
the programmed default speed to regulate the
vehicle’s speed. The default speed programmed
at the factory is 4 mph (Canada: 6 km / h). The
default speed can be reprogrammed using the
control system (
page 178). The next time DSR
is switched on, DSR will use the newly pro-
grammed default speed to regulate the vehicle’s
speed.
Once DSR is switched on, you can adjust the set
speed using the cruise control lever
(
page 245). Keep in mind that adjusting the
set speed using the cruise control lever with DSR
switched on will not change the programmed
default speed. If DSR is switched off and then
switched on again, DSR will use the programmed
default speed.
Depending on the road surface and level of
downhill grade, the DSR may not be able to
maintain the set speed. To maintain the set
speed, apply the brakes if necessary.
Warning!G
If the accelerator pedal is depressed while
the Downhill Speed Regulation is activated,
the vehicle can drive faster than the pro-
grammed set speed. You should therefore
drive downhill with particular caution as it
could otherwise lead to an accident and/or
serious injury to you or others. Keep in mind
that as soon as you remove the foot from
the accelerator pedal with the DSR switched
on, the DSR will start regulating the vehicle’s
speed including use of brakes if required.
Depending on the programmed set speed,
actual vehicle speed and gradient, the DSR
can cause the vehicle to slow down rapidly.
Sudden and unexpected deceleration can
result in loss of vehicle control, causing an
accident and/or serious personal injury to
you and others.

260 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 or start the
engine
and

release the parking brake
and

set the automatic transmission to
positionD,R, orN
The Parktronic system deactivates at
vehicle speeds exceeding approximately
11 mph (18 km/h). At lower vehicle
speeds the Parktronic system turns on
again.The Parktronic system also deactivates
when you set the automatic transmission
to positionP 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
The operational function of the Parktronic
system can be affected by dirty sensors,
especially at times of snow and ice. See
“Cleaning the Parktronic system sensors”
(
page 394).
Interference caused by other ultrasonic
signals (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.
Warning!G
Make sure no persons or animals are in the
area in which you are maneuvering. You
could otherwise injure them.


261 Controls in detail
Driving systems
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 394).Front sensors
Rear sensors
Minimum 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
longer be indicated by the system.
!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 sources (e.g.
working jackhammers, car wash or the air brakes
of trucks) may impair the operation of the
Parktronic system.
Centerapprox. 40 in (100 cm)
Cornersapprox. 24 in (60 cm)
Centerapprox. 48 in (120 cm)
Cornersapprox. 32 in (80 cm)
Centerapprox. 8in (20cm)
Cornersapprox. 6in (15cm)

263 Controls in detail
Driving systems
Switching the Parktronic system*
on/off
You can switch off the Parktronic system
manually.
The Parktronic switch is located in the
upper part of the center console.
1Parktronic switch
2Indicator lampSwitching off
Press Parktronic switch1.
Indicator lamp2 comes on.
Switching on
Press Parktronic switch1 once more.
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 Light
Truck Center as soon as possible.
If only the red distance segments illumi-
nate and no acoustic warning sounds, the
Parktronic system sensors are dirty (e.g.
slush, snow or ice) or there is an interfer-
ence from other radio or ultrasonic signals
(e.g. working jackhammers, car wash or
the air brakes of trucks). The Parktronic
system will automatically switch off after
20 seconds and the indicator lamp in the
Parktronic switch comes on.iThe Parktronic system switches on
automatically when you switch on the ignition
(
page 40).
Vehicles with original equipment Mercedes-Benz
Trailer Hitch Kit:
The rear Parktronic sensor will automatically
disengage when towing a trailer.

312 Operation
Driving instructions
Power assistance
BrakesTo 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.
Warning!G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle.
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 re-
duced 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.
!Operational or performance test must only
be conducted on a two-axle dynamometer. If
such tests are necessary, contact an authorized
Mercedes-Benz Light Truck Center. You could
otherwise seriously damage the brake system or
the transfer case which is not covered by the
Mercedes-Benz Limited Warranty.
!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
position0or1) when testing the parking brake
on a brake test dynamometer and such testing
should be no longer than 10 seconds.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.