Page 79 of 344

79 Safety and Security
Driving and safety systems
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 trans-
ferred to the wheel(s) with traction.
The traction control engages at vehicle
speeds up to approximately 24 mph
(40 km / h), and switches off at approxi-
mately 50 mph (80 km / h).
The {indicator lamp in the instrument
cluster (
page 25) comes on when you
turn the key to position2. It goes out when
the engine is running.
The 4-ETS / ESP warning lampv, loca-
ted in the speedometer dial, starts to flash
at any vehicle speed, as soon as the tires
lose traction and the wheels begin to spin.
Warning!
G
When you see the 4-ETS / ESP-warning
lampv flashing in the speedometer,
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 resul-
ting from excessive speed.
!Because of the ESP’s automatic opera-
tion, the engine must be shut off
(SmartKey in starter switch position0
or1) when the parking brake is being
tested on a brake test dynamometer.
Active braking action through ESP may
otherwise seriously damage the front
or rear axle brake system.
Operational tests with the engine
running can only be conducted on a
two-axle dynamometer.iIf the yellow 4-ETS malfunction indica-
tor lamp{ comes on while the
4-ETS / ESP warning lampv flash-
es, the electronic traction system is be-
ing switched off temporarily to prevent
overheating of the drive wheel brakes.
Page 194 of 344

194 OperationDriving instructionsBrakes
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.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 res-
ervoir.
Have the brake system inspected immedi-
ately. Contact your authorized
Mercedes-Benz Light Truck Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact your authorized
Mercedes-Benz Light Truck 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 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 78).
Page 195 of 344

195 Operation
Driving instructions
Install only brake pads and brake fluid
recommended by Mercedes-Benz.
After hard braking, it is advisable to drive
on for some time, rather than immediately
parking, so 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 ex-
tended 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.
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.
Page 210 of 344

210 OperationDriving instructions
The vehicle and trailer combination is
heavier, and therefore is limited in ac-
celeration and climbing ability, and re-
quires longer stopping distances.
I t i s m o r e p r o n e t o r e a c t i n g t o s i d e w i n d
gusts, and requires more sensitive
steering input.
If possible, do not brake abruptly, but
rather engage the brake slightly at first
to permit the trailer to activate its
brake. Then increase the braking force.
If the transmission hunts between
gears on inclines, manually shift to a
lower gear (select 4, 3, 2 or 1).
A lower gear and reduction of speed re-
duces the chance of engine overload-
ing and / or overheating.
On very steep inclines, not manageable
with gear selector lever in position1,
switch transfer case to LOW RANGE
mode (
page 125).
When going down a long hill, shift into
a lower gear and use the engine’s brak-
ing effect.
Avoid riding the brakes, thus overheat-
ing the vehicle and trailer brakes.
If the engine coolant rises to an ex-
tremely high temperature (coolant tem-
perature needle approaching the red
zone) when the air conditioning is on,
turn off the air conditioning system.
Engine coolant heat can be additionally
vented by opening the windows,
switching the climate control fan speed
to high and setting the temperature
control to the maximum hot position.
Extreme care must be exercised since
your vehicle with a trailer will require
additional passing distance ahead than
when driving without a trailer.
Because your vehicle and trailer is
longer than your vehicle alone, you will
also need to go much farther ahead of
the passed vehicle before you can re-
turn to your lane.
!If the trailer should begin to sway, re-
duce the vehicle’s speed and use the
brake controller by hand to straighten
out the vehicle and trailer.
In no case should you attempt to
straighten out the tow vehicle and trail-
er by increasing the speed or overstee-
ring and stepping on the brakes.
Page 249 of 344

249 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
/
The yellow coolant warning lamp
comes on when the engine is
running.
The coolant is to hot.
The coolant level is too low.
Stop as soon as possible and allow
the engine and coolant to cool down.
Check the coolant level and add
coolant if necessary (
page 222).
If the warning lamp comes on frequently,
there is a leak in the cooling system.
Have the cooling system checked by
an authorized Mercedes-Benz Light
Truck Center.
The coolant temperature gauge is above
248 °F (120 °C).
The coolant level is too low.
Stop as soon as possible and allow
the engine and coolant to cool down.
Add coolant to prevent engine from
overheating (
page 222).
If the coolant level is correct, the electrical
radiator fan may be broken.
If the coolant temperature is below
the red zone, drive on to the nearest
authorized Mercedes-Benz Light
Truck Center.
Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.