Coupling A Trailer; Electrical Connections; Weights And Ratings - Mercedes-Benz 2009 M-Class Operator's Manual

Do not attach rental hitches or other
bumper-type hitches to them.
To reduce the possibility of damage,
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remove the hitch ball adapter from the
receiver when not in use.

Electrical connections

The vehicle is prewired to accept the seven-
wire harness included in the Mercedes-Benz
approved trailer hitch receiver kit.
i A four-pole conversion plug is available
from your authorized Mercedes-Benz
Center as a spare part.
For further information, contact an
authorized Mercedes-Benz Center.
Vehicle and trailer weights and ratings
The Gross Trailer Weight (GTW) is the weight
of the trailer plus the weight of all cargo,
equipment, luggage, etc. loaded on the
trailer. The maximum permissible gross
trailer weight to be towed: 7 200 lb (3 265 kg).
Trailer Tongue Weight Rating (TWR) is the
maximum permissible weight on the trailer
tongue: 576 lb (261 kg) limit for Mercedes-
Benz approved hitch receiver.
Loading a trailer
When loading a trailer, you should observe
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that neither the permissible GTW, nor the
Gross Vehicle Weight Rating (GVWR) are
exceeded. The GVWR is indicated on the
certification label located on the driver's
door B-pillar ( Y page 248).
Maximum permissible values are listed on
the safety compliance certification labels
for the vehicle and for the trailer to be
towed.
The lowest value listed must be selected
when determining how the vehicle and
trailer are loaded.
The Tongue Weight (TW) at the hitch ball
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must be added to the Gross Vehicle Weight
(GVW) to prevent exceeding your
Mercedes-Benz tow vehicle's rear Gross
Axle Weight Rating (GAWR). The GVW and
GAWR are indicated on the certification
label located on the driver's door B-pillar
( Y page 248).
i Mercedes-Benz recommend loading the
trailer in such a manner that it has a TW
between 8 % and 15 % of the GTW.
i Maximum trailer weight ratings are
calculated assuming the vehicle, plus
Driving instructions
driver. The weight of other accessories,
passengers and cargo will reduce the
maximum trailer weight and TW your
vehicle can tow.
Checking weights of vehicle and trailer
To assure that the towing vehicle and trailer
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are in compliance with the maximum
permissible weight limits, have the loaded
rig (towing vehicle including driver,
passengers and cargo, trailer fully loaded)
weighed on a commercial scale.
Check the vehicle's front and rear Gross
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Axle Weight (GAW), the Gross Trailer
Weight (GTW) and Tongue Weight (TW).
The values as measured must not exceed
the weight limits listed under "Vehicle and
trailer weights and ratings" (

Coupling a trailer

G Warning!
Vehicles with air suspension program:
While you are coupling or decoupling a
trailer, make sure nobody locks or unlocks
the vehicle and/or opens or closes doors
or the tailgate.
Operation
Y page 283).
Z
283