Towing - Mercedes-Benz 2009 M-Class Operator's Manual

Operation
Driving instructions
The vehicle's level could change and you
could endanger yourself and/or others as
a result.
Make sure that you do not operate the ADS
switch or the vehicle level control system
when coupling/decoupling the trailer.
Observe maximum permitted trailer
dimensions (width and length).
Most states and all Canadian provinces
require
safety chains between the towing vehicle
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and the trailer
The chains should be criss-crossed under
the trailer tongue. They must be attached
to the hitch receiver, and not to the
vehicle's bumper or axle.
Make sure to leave enough slack in the
chains to permit turning corners.
a separate brake system at various trailer
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weights
a break-away switch on trailers with a
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separate brake system.
Check with your local state laws for specific
requirements.
The switch activates the trailer brakes in
the possible event that the trailer might
separate from the tow vehicle.
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! Do not connect a trailer brake system (if
trailer is so equipped) directly to the
vehicle's hydraulic brake system, as your
vehicle is equipped with antilock brakes. If
you do, neither the vehicle's brakes nor the
trailer's brakes will function properly.
i The provided vehicle electrical wiring
harness for trailer towing has a brake signal
wire for hook-up to a brake controller.
X
Make sure the automatic transmission is in
park position P ( Y page 130).
X
Engage the parking brake for the vehicle
( Y page 127).
X
Start the engine ( Y page 122).
X
Vehicles with air suspension program:
Set the vehicle level to highway
( Y page 171).
X
Vehicles with air suspension program:
Set the ADS to AUTO or COMF
( Y page 170).
X
Turn off the engine ( Y page 127).
X
Close all doors and the tailgate.
X
Attach the trailer.
X
Plug in all electrical connectors.
i Vehicles with air suspension program:
When you are towing a trailer, the vehicle
level always remains in the highway setting.
The following applies additionally when
towing a trailer:
The vehicle is lowered to the highway
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level when it reaches a speed of 5 mph
(8 km/h) if not set to highway level.
The highspeed level is not available.
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The restrictions that apply to towing also
apply when using accessories that are
connected to the trailer power socket, such
as a bicycle rack.
Towing a trailer
There are many different laws, including
speed limit restrictions, having to do with
trailer towing. Make sure your rig will be legal,
not only for where you reside, but also for
where you will be driving. A good source for
this information can be the police or local
authorities.
Note the following, when driving with a trailer:
In order to gain skill and an understanding
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of the vehicle's behavior, you should