Towing a trailer
Notes on towing a trailer
Important safety notes
GWARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
GWARNING
When the vehicle/trailer combination begins
to lurch, you could lose control of it. The vehi- cle/trailer combination could even rollover.
There is a risk of an accident.
On no account should you attempt to
straighten up the vehicle/trailer combination
by increasing the speed. Reduce vehicle
speed and do not countersteer. Apply the
brake as necessary.
GWARNING
If you install a ball coupling other than the one
delivered with the vehicle, the trailer tow hitch and the rear axle may be overloaded. This
applies especially if the ball coupling in ques- tion is longer or angled differently. This could seriously impair the driving characteristics
and the trailer can come loose. There is a risk
of an accident.
Only install the ball coupling delivered with
the vehicle or a ball coupling that is designed
to meet your trailer towing requirements. Do
not modify the ball coupling or the trailer tow hitch.
GWARNING
If the ball coupling is not installed correctly or not secured with the bolt provided and the
corresponding spring cotter, the trailer may
come loose. There is a risk of an accident.
Always install and secure the ball coupling asdescribed. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter.
Please observe the manufacturer's operating instructions for the trailer coupling if a
detachable trailer coupling is used.
Exceeding the maximum permissible nose-
weight may cause damage to the following: R your vehicle
R the trailer
R the ball coupling
R trailer tow hitch
The vehicle/trailer combination could
become unstable.
If the noseweight used is lower than the min- imum permissible noseweight, the vehicle/
trailer combination could also become unsta-ble.
To avoid hazardous situations:
R make sure to check the noseweight before
each journey
R use a drawbar noseweight as close as pos-
sible to the maximum noseweight
R do not exceed the maximum permissible
noseweight
R do not use a noseweight lower than the
minimum permissible trailer drawbar nose-
weight
When backing up the vehicle towards the
trailer, make sure there is nobody between
the trailer and the vehicle.
The applicable permissible values, which
must not be exceeded, can be found:
R in your vehicle documents
R on the type plate of the trailer tow hitch and
trailer
R on the vehicle identification plate
Couple and uncouple the trailer carefully. If
you do not couple the trailer to the towing
vehicle correctly, the trailer could become
detached.
Towing a trailer137
Driving an d parking
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Make sure that the following values are not exceeded:
R the permissible trailer drawbar noseweight
R the permissible trailer load
R the permissible rear axle load of the towing
vehicle
R the maximum permissible gross vehicle
weight of both the towing vehicle and thetrailer
When towing a trailer, your vehicle's handling
characteristics will be different in comparison with when driving without a trailer.
The vehicle/trailer combination:
R is heavier
R is restricted in its acceleration and gradi-
ent-climbing capability
R has an increased braking distance
R is affected more by strong crosswinds
R demands more sensitive steering
R has a larger turning radius
This could impair the handling characteris-
tics. Adapt your driving style accordingly.
Maintain a safe distance. Drive carefully.
When towing a trailer, always adjust your
speed to the current road and weather con-
ditions. Do not exceed the maximum permis- sible speed for your vehicle/trailer combina-tion.
You will find the values approved by the man-
ufacturer on the vehicle identification plates
and those for the towing vehicle in the "Tech- nical data" section ( Ypage 268).
Driving tips
X
On long and steep downhill gradients,
select shift range 1,2 or 3(Y page 107) in
good time.
iThis also applies if you have activated
cruise control or SPEEDTRONIC.
X If necessary, shift the transfer case to LOW
RANGE (Y page 132).
This will use the braking effect of the
engine, so that less braking will be required to maintain the speed. This relieves the
load on the brake system and prevents the
brakes from overheating and wearing too
quickly. If you need additional braking,
depress the brake pedal repeatedly rather
than continuously.
The maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check
the trailer's documents to see what the max- imum permissible speed is. Observe the
legally prescribed maximum speed in the rel-evant country.
For certain Mercedes-Benz vehicles, the max-
imum permissible rear axle load is increased
when towing a trailer. Refer to the "Technical
data" section to find out whether this applies to your vehicle. If you utilize any of the added
maximum rear axle load when towing a trailer, the vehicle/trailer combination may not
exceed a maximum speed of 60 mph
(100 km/h) for reasons concerning the oper-ating permit. This also applies in countries in
which the permissible maximum speed for
vehicle/trailer combinations is above 60 mph (100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
to when driving without a trailer and it will
consume more fuel.
On long and steep downhill gradients, you
must select shift range 1,2 or 3in good time.
iThis also applies if you have activated
cruise control or DISTRONIC PLUS.
This will use the braking effect of the engine,
so that less braking will be required to main-
tain the speed. This relieves the load on the
brake system and prevents the brakes from
overheating and wearing too quickly. If you
need additional braking, depress the brake
pedal repeatedly rather than continuously.
138Towing a trailer
Driving and parking
XSecure the bolt using spring cotter D.
Correctly installed and secured ball couplingX
Check the ball coupling, bolt and spring
cotter for correct installation.
Coupling up a trailer
GWARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun brake
is engaged.
!Do not connect the trailer's brake system
(if featured) to the hydraulic brake system
of the towing vehicle, as the latter is equip-
ped with an anti-lock brake system. Doing
so will result in a loss of function of the
brake systems of both the vehicle and the
trailer.
Observe the maximum permissible trailer
dimensions (width and length). Most U.S. states and all Canadian provinces
require by law:
R safety chains between the towing vehicle
and the trailer. The chains should be cross-
wound under the trailer drawbar. They must
be fastened to the vehicle's trailer cou-
pling, not to the bumper or the axle.
Allow for enough play in the chains to facil- itate turning tight corners.
R a separate brake system for certain types
of trailer.
R a safety switch for braked trailers. Check
the specific legal requirements applicable
to your state.
If the trailer detaches from the towing vehi-
cle, the safety switch applies the trailer's
brakes.
X Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's parking brake.
X Couple up the trailer.
X Establish all electrical connections.
Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed
restrictions. Make sure that your vehicle/
trailer combination complies with the local
requirements not only in your area of resi-
dence but also at any location to which you
are traveling. The police and local authorities
can provide reliable information.
Please observe the following when towing a
trailer:
R To acquaint yourself with driving with a
trailer and with the resulting changes to
handling, you should practice cornering,
Towing a trailer141
Driving and parking
Z
stopping and backing up in a traffic-free location.
R Before driving, check:
- Trailer tow hitch
- Safety switch for braked trailers
- Safety chains
- Electrical connections
- Lights
- Wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer features electronically control-
led brakes, pull away the vehicle/trailer
combination carefully, manually brake
using the brake controller, and check the
brakes for correct function.
R Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion.
R If you couple up a trailer, regularly check
the cargo for secure fastening and make
sure that the trailer lamps and (if applica-
ble) the trailer brakes are functioning cor-rectly.
R Bear in mind that the handling will be less
stable when towing a trailer than when driv-
ing without one. Avoid sudden steeringmovements.
R The vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
R If possible, avoid abrupt braking. Depress
the brake pedal moderately at first, so that
the trailer can activate its own brakes. Thenincrease the pressure on the brake pedal.
R If the automatic transmission continues to
shift back and forth between two gears
when driving up or downhill, restrict the
shift range. Select shift range 4, 3, 2,or1.
A lower gear and lower speed reduce the
risk of engine failure. R
When driving downhill, shift to a lower gear
to utilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
R If the coolant temperature increases dra-
matically while the air-conditioning system
is switched on, switch off the air-condition-
ing system.
Coolant heat can additionally be dissipated
by opening the windows and by setting the
blower fan and the interior temperature tomaximum.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of your vehicle/trailer
combination, you will have to travel an addi-
tional distance beyond the vehicle you are
overtaking before returning to the previous lane.
Decoupling a trailer
!
Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the rebound- ing of the overrun brake.
X Make sure that the automatic transmission
is set to position P.
X Apply the parking brake.
X Start the engine.
X Close all doors, including the rear door.
X Apply the trailer's parking brake.
X Detach the trailer cable and decouple thetrailer.
X Switch off the engine.
Permissible trailer and drawbar loads
Weight specifications
The gross trailer weight is calculated by add-
ing the weight of the trailer to the weight of
142Towing a trailer
Driving and parking
Display messagesPossible causes/consequences andMSolutions
÷
Inoperative. See
Operator's Manual
ESP®
, BAS, the HOLD function, hill start assist and ESP ®
trailer
stabilization are unavailable due to a malfunction.
BAS and the adaptive brake lights may also have failed.
In addition, the ÷andå warning lamps light up in the
instrument cluster.
GWARNING
The brake system continues to function normally, but without the functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Drive on carefully.
X Visit a qualified specialist workshop.
T !
÷
Inoperative. See
Operator's Manual
EBD (electronic brake force distribution), ABS, ESP ®
, BAS, the
HOLD function, hill start assist and ESP ®
trailer stabilization are
unavailable due to a malfunction.
BAS and the adaptive brake lights may also have failed.
In addition, the ÷,å and! warning lamps light up in the
instrument cluster and a warning tone sounds.
GWARNING
The brake system continues to function normally, but without the functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Drive on carefully.
X Visit a qualified specialist workshop immediately.
F(USA
only)
!(Canada
only)
ReleasePark.Brake
You are driving with the parking brake applied. A warning tone also sounds.
X Release the parking brake.
Display messages151
On-board computer and displays
Z
Driving systems
Display messagesPossible causes/consequences andMSolutions
TC shift condiZ
tionsnotfulfilled
Apply the brake/
parking brake
The parking brake has not been applied and the brake pedal has
not been depressed. The transfer case has canceled the gear
change process and is inNeutral. There is no connection between
the engine and the drive wheels.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Depress the brake pedal and apply the parking brake.
X Shift the automatic transmission to neutral position N.
X Make sure all conditions for changing gears are met(Y page 132).
X Repeat the gearshift process.
TC malfunction
Consult workshop
aboutapplyingthe
parking brake
There is a malfunction in the transfer case.
X Do not shift the transfer case.
X When parking, secure the vehicle against rolling away (Y page 110).
X Have the vehicle checked at a qualified specialist workshop.
TC shift canceled
Reactivate
The transfer case has not performed the gear change process. XRepeat the gearshift process.
X Make sure all conditions for changing gears are met (Y page 132).
TC shift condiZ
tionsnotfulfilled
Max. speed 25 mph
You have exceeded the maximum speed for the gearshift process.
X Drive more slowly.
X Repeat the gearshift process.
TC shift condiZ
tionsnotfulfilled
SelectNEUTRALgear
You have not met one or more shift conditions.
X Shift the automatic transmission to neutral position N.
X Repeat the gearshift process.
TC shift condiZ
tionsnotfulfilled
Max. speed 40 mph
You have exceeded the maximum speed for the gearshift process.
X Drive more slowly.
X Repeat the gearshift process.
LOW RANGE
ON
The transfer case is in the LOW RANGEoff-road position.
HIGH RANGE
ON
The transfer case is in the HIGH RANGEon-road position.
156Displaymessages
On-board computer and displays
iWhen re-installing trim panel?, make
sure that retainer Aengages in recess B.
Removing the spare wheel
The spare wheel is heavy. Take particular note
of this when removing the spare wheel.
X Remove wheel nuts :.
X Remove the spare wheel.
Mounting the wheel
After changing a wheel:
X Repair or replace the damaged wheel as
soon as possible and secure the spare
wheel in place again.
X Secure the damaged wheel on the spare
wheel bracket with wheel nuts :. When
doing so, make sure that the wheel cannot
come loose.
X When re-installing trim panel ?, make sure
that retainer Bengages in recess A
( Y page 215). X
Make sure that tab ;is below when re-
installing cover ring :(Y page 215).
X For safety reasons, regularly check to
ensure that the wheel is securely fastened.
Flat tire
Preparing the vehicle
XStop the vehicle on solid, non-slippery and
level ground, as far away as possible from
traffic.
X Switch on the hazard warning lamps(Y page 90).
X Apply the parking brake.
X Bring the front wheels into the straight-
ahead position.
X Move the selector lever to position P.
X Switch off the engine.
X Remove the SmartKey from the ignitionlock.
The steering wheel lock stays active for as
long as the SmartKey is removed.
X All occupants must get out of the vehicle.
Make sure that they are not endangered as
they do so.
X Make sure that no one is near the danger
area while a wheel is being changed. Any-
one who is not directly assisting in the
wheel change should, for example, stand
behind the barrier.
X Get out of the vehicle. Pay attention to traf-
fic conditions when doing so.
X Close the driver's door.
Battery (vehicle)
Important safety notes
Special tools and expert knowledge are
required when working on the battery, e.g.
removal and installation. You should there-
fore have all work involving the battery car-
ried out at a qualified specialist workshop.
216Battery (vehicle)
Roadside Assistance
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged,the engine can be jump-started from another vehicle or from a second battery using jumper
cables. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or a jump-starting device.
R Vehicles with a gasoline engine: only jump-start the vehicle when the engine and exhaust
system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may only be performed from batteries with a nominal voltage of 12 V.
R Only use jumper cables which have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start. This charges the battery slightly.
R Make sure that the two vehicles do not touch.
Make sure that:
R the jumper cables are not damaged.
R when the jumper cables are connected to the battery, uninsulated sections of the terminal
clamp do not come into contact with other metal sections.
R The jumper cables cannot come into contact with parts such as the pulley or the fan. These
parts move when the engine is started and while it is running.
X Apply the parking brake.
X Move the selector lever to position P.
X Switch off all electrical consumers (e.g. radio, blower, etc.).
X Open the hood ( Ypage 205).
Position number Bidentifies the charged battery of the other vehicle or an equivalent jump-
starting device.
Jump-starting221
Roadside Assistance
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