Off-road driving
Overview of off-road driving systems
The systems which are relevant for off-road driving are explained on the following pages:
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4MATIC (permanent four-wheel drive), for optimum traction
-
DSR (Downhill Speed Regulation), which assists you when driving downhill
-
Off-road drive program, which assists you when driving off-road
-
LOW RANGE* off-road gear for better traction off-road
-
Differential locks for increased traction off-road
You will find further information about driving off-road in the "Operation" section more.
4MATIC (permanent four-wheel drive)
4MATIC ensures that all four wheels are permanently driven. Together with ESP® and 4ETS, it improves the traction of your vehicle whenever a drive wheel spins due to insufficient grip.
 | Risk of accident |
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4MATIC cannot reduce the risk of an accident if you drive too fast.
If a drive wheel spins due to insufficient grip:
-
Only depress the accelerator pedal as far as necessary when pulling away.
-
Accelerate less when driving.
-
Adapt your driving style to suit road and traffic conditions.
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In wintry driving conditions, the maximum effect of 4MATIC can only be achieved if you use winter tyres (M+S tyres), with snow chains if necessary.
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When testing the parking brake, operate the vehicle only briefly (for a maximum of ten seconds) on a brake dynamometer. When doing this, turn the key to position 0 or 1 in the ignition. Failure to do this can cause damage to the drive train or the brake system.
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A function or performance test should only be carried out on a twin-axle dynamometer. If you wish to operate the vehicle on such a dynamometer, please consult a Mercedes-Benz Service Centre in advance. You could otherwise damage the drive train or the brake system.
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DSR (Downhill Speed Regulation)
You will find
information about driving off-road in the "Operation" section
more.
DSR is an aid to
assist you when driving downhill. It keeps the speed of travel at the speed set
on the on-board computer
more.
The steeper the downhill gradient, the greater the DSR braking effect on the
vehicle. When driving on flat stretches of road or on an uphill gradient, the
DSR braking effect is minimal or non-existent.
| Risk of accident |
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DSR is only an aid designed to assist you when driving downhill. You are responsible for keeping control of the vehicle and for assessing whether the downhill gradient can be managed.
When activating DSR the vehicle may brake suddenly due to DSR intervening. This is dependent on the downhill gradient and the difference between the current speed and the speed set. DSR may not always be able to keep to the set speed, depending on road surface and tyre conditions. You could lose control of the vehicle and cause an accident.
Select a set speed suitable for the prevailing conditions and when necessary, apply the brakes manually.
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DSR controls the
vehicle's speed when DIRECT SELECT selector lever positions D,
R and N are selected. You can drive at a higher or a lower
speed than that set on the on-board computer at any time by braking or
accelerating.
| Risk of accident |
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If you depress the accelerator pedal with DSR activated, then the set speed can be exceeded. Drive downhill with special care and always keep in mind that DSR brakes the vehicle as soon as you remove your foot from the accelerator pedal. The vehicle may be heavily braked by DSR depending on the gradient and the difference between the vehicle's road speed and the set speed. You could lose control of the vehicle and cause an accident.
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The speed is set to
6 km/h at the factory.
Activating/deactivating DSR
Activating
You can only
activate DSR when driving at a speeds below 30 km/h.
 |
 | To activate/deactivate
DSR |
 | Indicator
lamp |
|
Vehicle
with AIRMATIC package*
 |
Press button
.
|
| |
Indicator lamp
lights
up.
|
If the current
vehicle speed is too high, the DSR symbol appears on the multi-function display
with the
max.
speed 30 km/h
message.
Deactivating
| |
Press button
.
|
| |
Indicator lamp
goes out.
The DSR symbol
appears in the multi-function display with the
Off
message
|
DSR switches off
automatically if you drive faster than 35 km/h. The DSR symbol
appears in the multi-function display with the
Off
message. You also hear a warning tone.
Changing the
set speed while the vehicle is in motion
When DSR is
activated, you can change the set speed to a value between 4
km/h and 18 km/h while the vehicle is in motion.
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| To increase set
speed |
| To reduce set
speed |
|
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To increase or
reduce the set speed by 1 km/h increments: briefly press
the cruise control lever to the pressure point up
for a higher set
speed or down
for a lower set speed.
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The set value
appears in the multi-function display.
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To increase or
reduce the set speed in 10 km/h increments: briefly press
cruise control beyond the pressure point up
for a higher set
speed or down
for a lower set speed.
|
| |
The set value
appears in the multi-function
display.
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Off-road drive program
Only vehicles
without the Off-Road Pro engineering package* feature the off-road drive
program.
The
off-road drive program assists you in driving off-road and when fording. The
engine's performance characteristics and the gearshifting characteristics of
the automatic transmission are adapted for this purpose. ABS, ESP® and 4
ETS programs especially adapted to off-road driving are also activated.
Do not use the
off-road drive program on roads that are snowy or icy or if you have fitted
your vehicle with snow chains.
ML 63 AMG
You can activate
and deactivate the off-road drive program using the on-board computer
more.
All models
except ML 63 AMG
 |
| Off-road button |
| Indicator
lamp |
|
 |
 | Off-road
display |
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LOW RANGE* off-road gear
Only vehicles equipped with the Off-Road Pro engineering
package* feature the LOW
RANGE off-road gear.
The LOW RANGE
off-road gear assists you in driving off-road and when fording. When LOW RANGE
is engaged, the engine's performance characteristics and the gearshifting
characteristics of the automatic transmission are adapted for this purpose.
ABS, ESP® and 4 ETS programs especially adapted to off-road
driving are also activated. You will find information about driving off-road in
the "Operation" section
more. You will find information about driving safety systems in
conjunction with LOW RANGE in the "Safety" section
more.
Shift
ranges
|
HIGH
RANGE
|
Road position for
all normal driving situations
|
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LOW
RANGE
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Off-road position
for driving off-road and fording
The gear ratio
between the engine and wheels is only approximately one third of that in the
HIGH RANGE road position. The drive torque is correspondingly higher as a
result.
Do not use LOW RANGE:
-
on slippery road
surfaces, e.g. in the case of slush
-
on snow or
ice-covered roads
-
if you have snow
chains on your vehicle
|
| Risk of accident |
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Always wait for the gear change process from HIGH RANGE to LOW RANGE - and from LOW RANGE to HIGH RANGE - to complete. Do not turn off the engine while changing gear and do not switch the automatic transmission to another gear.
If you do not wait for the gear change process to complete, it may not be correctly implemented. The transfer case may then be in neutral and the connection between the engine and the drive axles may be disengaged. The vehicle could then move freely, even if a gear is engaged, and could inadvertently start moving, particularly if it is on a slope.
Observe the messages in the multi-function display.
|
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| LOW RANGE button |
| Indicator
lamp |
|
|
| LOW RANGE
display |
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From HIGH RANGE
to LOW RANGE
| |
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Only carry out the gear change process if:
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While indicator
lamp is
flashing, you can cancel the gear change by pressing LOW RANGE button
again.
From LOW RANGE
to HIGH RANGE
| |
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Only carry out the gear change process if:
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While indicator
lamp is
flashing, you can cancel the gear change by pressing LOW RANGE button
again.
Messages in the
multi-function display
If a gear change process has
not been successful, the following messages may be displayed in the
multi-function display:
-
Max.
speed 40 km/h
You have been
driving faster than 40 km/h. Indicator lamp
also
flashes.
| |
Drive more slowly
to carry out the gear change process.
|
-
Engage N
briefly
The automatic
transmission is in D and you are now driving below 40
km/h.
| |
Move the DIRECT
SELECT selector lever to N to carry out the gear change
process.
|
-
Shifting
process cancelled Reactivate
The gear change
process was not carried out.
| |
Maintain all gear
change conditions and carry out the gear change process
again.
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Stop vehicle.
Apply parking brake
An acoustic warning
will also sound. The gear change process has not been completed. LOW RANGE is
in the neutral position. There is no connection between the engine and the
drive wheels.
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Do not drive any
further, otherwise you could damage the vehicle's drive train.
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Stop the vehicle.
Take into account the road and traffic conditions when doing
this.
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Depress the parking
brake.
|
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Carry out the gear
change process again.
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If the gear change
process has been carried out, the Stop vehicle.Apply parking brake
message
disappears.
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Differential locks
Differential locks
improve the vehicle’s traction.
If your vehicle
is equipped with the Off-Road Pro engineering package*, it is fitted with:
-
A differential lock
for the transfer box: this controls the balance between the front and rear
axles.
-
A differential lock
for the rear axle: this controls the balance between the wheels and the rear
axle.
4ETS
more controls the compensation between the wheels and the front
axle.
Engaging the
differential locks
 |
| Selector wheel |
| AUTO mode |
| To engage the differential lock for
the transfer case |
 | To engage the differential lock for
the transfer case and rear axle |
|
AUTO
mode
Use
AUTO mode for
all driving situations, including driving off-road or when fording.
In AUTO mode, the
differential locks are engaged and disengaged according to driving
requirements. This guarantees sufficient traction for most driving situations
with unrestricted vehicle steerability.
| |
Start the
engine.
|
| |
The differential
locks are in AUTO mode. The indicator lamp in selector wheel
lights up above
symbol for AUTO mode .
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Engaging
manually
| Risk of accident |
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When driving on a firm road surface, only drive in AUTO mode, never with manually engaged differential locks. If differential locks have been engaged manually, the vehicle's steerability is greatly impaired and the risk of accident thereby increased.
Do not manually engage or disengage the differential locks while cornering. The vehicle motion could otherwise be jerky. You could lose control of the vehicle as a result and cause an accident.
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Only engage the
differential locks manually if traction in AUTO mode is insufficient.
At speeds of up to 30 km/h, you can engage the
differential locks in this order:
, then
.
 |
 | The differential lock for the
transfer case is locked. |
|
The differential
locks are not controlled automatically. The steerability of the vehicle is
restricted considerably. Drive carefully and accelerate gently for optimum
traction.
You
can switch back to AUTO mode at any time. For safety reasons, the differential
locks disengage automatically at speeds above 50 km/h. If you
stop the vehicle and switch off the ignition for longer than ten seconds, the
differential locks switch back to AUTO mode.
Message in the
multi-function display
Diff. lock
system overheated. Wait briefly
The differential lock system
has overheated and briefly disengaged.
| |
Continue
driving.
|
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The differential
locks cool off and are soon available once
again.
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