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88 Safety and Security
Driving safety systems
In this section you will find information on
the following driving safety systems:
ABS (Antilock Brake System)
BAS (Brake Assist System)
4-ETS (Electronic Traction System)
EBB (Electronic Brake Booster)
ESP® (Electronic Stability Program)
ABS
The Antilock Brake System (ABS) regulates
the brake pressure so that the wheels do
not lock during braking. This allows you to
maintain the ability to steer your vehicle.
The ABS is functional above a speed of
approximately 5 mph (8 km/h) indepen-
dent of road surface conditions (as long as
the differential locks are not engaged).
Warning!G
The following factors increase the risk of
accidents:
Excessive speed, especially in turns
Wet and slippery road surfaces
Following another vehicle too closely
The driving safety systems described in this
section cannot reduce these risks or pre-
vent the natural laws of physics from acting
on the vehicle.
Always adapt your driving style to the pre-
vailing road and weather conditions and
keep a safe distance to other road users and
objects on the street.
iIn winter operation, the maximum effective-
ness of the ABS, the BAS, the ESP®, the EBB, and
the 4-ETS is only achieved with winter tires or
snow chains as required.
Warning!G
Do not pump the brake pedal. Use firm,
steady brake pedal pressure instead. Pump-
ing the brake pedal defeats the purpose of
ABS and significantly reduces braking effec-
tiveness.
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Continuous steady brake pedal pressure
yields the advantages provided by the ABS,
namely braking power and the ability to
steer the vehicle.
On slippery road surfaces, the ABS will
respond even to light brake pressure. The
pulsating brake pedal can be an indication
of hazardous road conditions and func-
tions as a reminder to take extra care while
driving.
The -indicator lamp in the instrument
cluster (
page 26) comes on when you
turn the SmartKey to position2. It goes
out when the engine is running.Braking
At the instant one of the wheels is about to
lock up, a slight pulsation can be felt in the
brake pedal, indicating that the ABS is in
the regulating mode.
Keep firm and steady pressure on the
brake pedal while experiencing the
pulsation.Emergency brake maneuver
Keep continuous full pressure on the
brake pedal.
Warning!G
When the ABS is malfunctioning, the BAS,
the EBB, the ESP®, and the 4-ETS are also
switched off. The basic driving and braking
functions are still available.
When the ABS is malfunctioning, the wheels
may lock during hard braking, reducing
steering capability and extending the brak-
ing distance.
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LOW RANGE– ABS
During off-road driving a special low range
system for the Antilock Brake System
(ABS) is operational with transfer case in
position LOW (
page 170).
An improved braking action (dig-in effect)
is obtained for vehicle speeds up to
37 mph (60 km/h) through a change in the
ABS control function.
For more information, see “Practical hints”
(
page 324).
BAS
The Brake Assist System (BAS) operates in
emergency situations. If you apply the
brakes very quickly, the BAS automatically
provides full brake boost, thereby poten-
tially reducing braking distance. Apply con-
tinuous full braking pressure until the
emergency braking situation is over. The
ABS will prevent the wheels from locking.
When you release the brake pedal the
brakes function again as normal. The BAS
is then deactivated.
With the BAS malfunctioning, the ABS,
ESP
®, and 4-ETS are also switched off.
Warning!G
The ABS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking or steering efficiency
beyond that afforded by the condition of the
vehicle brakes and tires or the traction
afforded. The ABS cannot prevent acci-
dents, including those resulting from
excessive speed in turns, following another
vehicle too closely, or hydroplaning. Only a
safe, attentive, and skillful driver can pre-
vent accidents. The capabilities of an ABS
equipped vehicle must never be exploited in
a reckless or dangerous manner which
could jeopardize the user’s safety or the
safety of others.
Warning!G
If the BAS is malfunctioning, the brake
system is still functioning normally, but
without the additional brake boost available
that BAS would normally provide in an emer-
gency braking maneuver. Therefore, the
braking distance may increase.
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91 Safety and Security
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For more information, see “Practical hints”
(
page 340).
4-ETS
The 4-Electronic Traction System (4-ETS)
improves vehicle’s ability to utilize avail-
able traction, especially under slippery
road conditions. The brakes are applied to
the spinning wheel and power is allowed to
flow to the wheel(s) with traction.
The 4-ETS function is available between
vehicle speeds of 0 mph (km/h) and
37 mph (60 km/h).
The ESP
® warning lampv in the instru-
ment cluster (
page 26) comes on when
you switch on ignition (
page 39). It goes
out when the engine is running.
The ESP
® warning lampv starts to
flash at any vehicle speed, as soon as a tire
loses traction and the wheel begins to
spin.
Warning!G
The BAS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking efficiency beyond that
afforded by the condition of the vehicle
brakes and tires or the traction afforded.
The BAS cannot prevent accidents, includ-
ing those resulting from excessive speed in
turns, following another vehicle too closely,
or hydroplaning. Only a safe, attentive, and
skillful driver can prevent accidents. The
capabilities of a BAS equipped vehicle must
never be exploited in a reckless or danger-
ous manner which could jeopardize the
user’s safety or the safety of others.
Warning!G
When you see the ESP® warning lampv
flashing in the instrument cluster, then
proceed as follows:
While driving off, apply as little throttle
as possible.
While driving ease up on the accelera-
tor.
Adapt your speed and driving style to
the prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The 4-ETS cannot prevent accidents result-
ing from excessive speed.
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92 Safety and Security
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For more information, see “Practical hints”
(
page 330).
EBB
The Electronic Brake Booster (EBB)
enhances braking effectiveness by allow-
ing the rear brakes to supply a greater
proportion of the braking effort in straight
line braking circumstances without a loss
of vehicle stability.
For more information, see the “Practical
hints” section (
page 327).
ESP®
The Electronic Stability Program (ESP®) is
operational as soon as the engine is run-
ning and monitors the vehicle’s traction
(force of adhesive friction between the
tires and the road surface) and handling.
The ESP
® recognizes when a wheel is
spinning or if the vehicle starts to skid.
By applying the brakes to the appropriate
wheel and by limiting engine output, the
ESP
® works to stabilize the vehicle.
The ESP® is especially useful while driving
off and on wet or slippery road surfaces.
The ESP
® also stabilizes the vehicle during
braking and steering maneuvers.
The ESP
® warning lampv in the instru-
ment cluster (
page 26) flashes when the
ESP® is engaged.
The ESP
® warning lampv comes on
when you switch on ignition (
page 39).
It goes out when the engine is running.
!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)
when testing the parking brake on a brake test
dynamometer and such testing should be no
longer than 10 seconds.
Active braking action through ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.
Warning!G
If the EBB is malfunctioning, the brake
system is still functioning. However, the rear
wheels may lock during hard braking, caus-
ing you to lose control over the vehicle and
possibly causing an accident. Adjust your
driving style to the non-operating status of
the EBB.
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93 Safety and Security
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Warning!G
Never switch off the ESP® when you see the
ESP® warning lampv flashing in the
instrument cluster. In this case proceed as
follows:
While driving off, apply as little throttle
as possible.
While driving ease up on the accelera-
tor.
Adapt your speed and driving style to
the prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The ESP
® cannot prevent accidents result-
ing from excessive speed.
Warning!G
The ESP® cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase the traction afforded. The ESP
®
cannot prevent accidents, including those
resulting from excessive speed in turns, fol-
lowing another vehicle too closely, or hydro-
planing. Only a safe, attentive, and skillful
driver can prevent accidents. The capabili-
ties of a ESP
® equipped vehicle must never
be exploited in a reckless or dangerous
manner which could jeopardize the user’s
safety or the safety of others.
!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 when
testing the parking brake on a brake test
dynamometer and such testing should be no
longer than 10 seconds.
Active braking action through ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.
iThe ESP® will only function properly if you
use wheels of the recommended tire size
(
page 416).
iThe ABS, BAS, and ESP® are automatically
switched off when the differential locks are
switched on (
page 175).
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94 Safety and Security
Driving safety systems
Switching off the ESP®
To improve the vehicle’s traction, switch
off the ESP® in driving situations where it
would be advantageous to have the drive
wheels spin and thus cut into surfaces for
better grip such as:
when driving with snow chains
in deep snow
sand or gravel
when driving off-roadWhen you switch off the ESP
®
the ESP® does not stabilize the vehicle
the engine output is not limited, which
allows the drive wheels to spin and
thus cut into surfaces for better grip
the 4-ETS will still apply the brake to a
spinning wheel
the ESP® continues to operate when
you are braking
you cannot activate the cruise control
system
the cruise control system switches off
if currently activatedThe ESP
® switch is located on the upper
part of the center console.
1ESP
® switch
With the engine running, press
switch1.
The ESP
® warning lampv in the
instrument cluster comes on.
The ESP
® is deactivated.
Warning!G
The ESP® should not be switched off during
normal driving other than in the circum-
stances described below. Disabling of the
system will reduce vehicle stability in stan-
dard driving maneuvers.
Warning!G
Switch on the ESP® immediately if the afore-
mentioned circumstances do not apply any-
more. Otherwise the ESP
® will not stabilize
the vehicle when it is starting to skid or a
wheel is spinning.
iWhen the ESP® is switched off and one or
more drive wheels are spinning, the ESP® warn-
ing lampv in the instrument cluster flashes.
However, the ESP
® will then not stabilize the
vehicle.
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95 Safety and Security
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Even if the ESP® has been switched off, it
is still active in the following situations:
when braking
at vehicle speeds up to approximately
37 mph (60 km/h), if one wheel
reaches the grip limit, e.g. when the
street is icy on one side
The brake is applied until the wheel
regains sufficient traction.
If one or more drive wheels are spinning,
the ESP
® warning lampv in the instru-
ment cluster flashes, regardless of the
speed.Switching on the ESP
®
Press switch1 once more.
The ESP
® warning lampv in the
instrument cluster goes out.
You are now again in normal driving
mode with the ESP
® switched on.
For more information, see “Practical hints”
(
page 330).
Warning!G
When the ESP® warning lampv is
illuminated continuously, the ESP® is
switched off or it is not operational due to a
malfunction.
Adapt your speed and driving to the prevail-
ing road conditions and to the non-operating
status of the ESP
®.
!Avoid spinning of a drive wheel for an
extended period of time with the ESP® switched
off. This may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
iIf the ESP® is switched off, it will be auto-
matically activated when exceeding a vehicle
speed of 37 mph (60 km/h) or exceeding a
severity threshold of side acceleration.