tow MERCEDES-BENZ GL 2012 Service Manual

Permissible trailer loads and drawbar
noseweights
Weight specifications
The Gross Trailer Weight (GTW) is the
combined weight of the trailer together with
the cargo and equipment loaded on the
trailer. Permissible gross weight: 7500 lb
(3402 kg).
The permissible Trailer drawbar Weight
Rating (TWR) is the maximum weight
permitted on the trailer drawbar: 600 lb
(272 kg) limit for Mercedes-Benz-approved
trailer couplings.
Loading a trailer
R When loading a trailer, please note that
neither the permissible gross trailer weight
nor the permissible Gross Vehicle Weight
Rating (GVWR) may be exceeded. The
permissible Gross Vehicle Weight Rating
(GVWR) is specified on the type plate
located on the B-pillar on the driver's side
of your vehicle.
You can find the maximum permissible
values on the type plates of your vehicle
and the trailer. Always observe the lowest
respective value when determining the
maximum weight with which you can load
the vehicle and the trailer.
R The drawbar noseweight acting on the ball
coupling has to be added to the rear axle
weight in order to prevent the permissible
Gross Axle Weight Rating (GAWR) from
being exceeded. The permissible Gross
Vehicle Weight Rating (GVWR) is specified
on the type plate located on the B-pillar on
the driver's side of your vehicle.
i Mercedes-Benz recommends loading the
trailer so that the drawbar noseweight
remains between 8% and 15% of the
permissible gross trailer weight.
i The weight of additional accessories,
passengers, and cargo reduces the
permissible trailer load and drawbar
noseweight for your vehicle.
Checking the vehicle and trailer weight
R To check that the weights of the towing
vehicle and the trailer comply with the
maximum permissible values, have the
vehicle/trailer combination (including the
driver, passengers, and cargo with a fully
laden trailer) weighed on a calibrated
weighbridge.
R Check the gross axle weight rating of the
front and rear axle, the Gross Trailer Weight
(GTW), and the drawbar noseweight.
Trailer power supply
The trailer power socket of your vehicle is
designed for connecting the 7-pin connector
supplied as part of the Mercedes-Benz-
approved trailer coupling.
i Depending on your trailer, you may need
an adapter to connect your trailer to the
vehicle.
Further information is available from any
authorized Mercedes-Benz Center.
Trailer towing213Driving and parkingZ

Driving systemsDisplay messagesPossible causes/consequences and M Solutions°
Level Selection
Not PermittedYou cannot change the vehicle level, because:
R you are exceeding the permissible speed for the selected
vehicle level.
R you are towing a trailer.
R the trailer-coupling socket is being used, e.g. for a bicycle rack.XDrive more slowly and then select the desired vehicle level again
( Y page 189).XObserve the notes on towing a trailer ( Y page 210).°
Compressor Cooling
DownYou have selected a higher vehicle level. The compressor first
needs to cool down because of frequent level changes.XDrive in a manner appropriate for the current vehicle level.XMake sure that there is sufficient ground clearance.XAllow the compressor to cool down.
When the compressor has cooled down, the display message
disappears. The vehicle then continues rising to the selected
level.°
MalfunctionLevel control is defective.XDo not drive faster than 50 mph (80 km/h).XMake sure that there is sufficient ground clearance.XHave the vehicle checked at a qualified specialist workshop.Æ
Reduce speed to
under 12 MPHGRisk of accident
You are exceeding the speed permissible for the selected off-road
level.
XAdjust your driving style to the altered handling characteristics.XOnly make slight steering movements and avoid fast steering
movements.XDo not drive faster than 12 mph (20 km/h).°
Rising Max. 12 MPHThe vehicle is being adjusted to off-road level 3. The display
message informs you of the maximum speed permissible for off-
road level 3.XDo not drive faster than 12 mph (20 km/h).°
Max. 12 MPHYou are driving in off-road level 3. The display message informs
you of the maximum speed permissible for off-road level 3.XDo not drive faster than 12 mph (20 km/h).248Display messagesOn-board computer and displays

Warning and indicator lamps in the instrument cluster
Seat belts
ProblemPossible causes/consequences and M Solutions7
After starting the
engine, the red seat
belt warning lamp lights
up for six seconds.The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.XFasten your seat belt ( Y page 55).7
After starting the
engine, the red seat
belt warning lamp lights
up. In addition, a
warning tone sounds
for up to six seconds.GRisk of injury
The driver's seat belt is not fastened.
XFasten your seat belt ( Y page 55).
The warning tone ceases.7
The red seat belt
warning lamp lights up
after the engine starts,
as soon as the driver's
or the front-passenger
door is closed.GRisk of injury
The driver or front passenger has not fastened their seat belt.
XFasten your seat belt ( Y page 55).
The warning lamp goes out.GRisk of injury
There are objects on the front-passenger seat.
XRemove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out.258Warning and indicator lamps in the instrument clusterOn-board computer and displays

ProblemPossible causes/consequences and M Solutions7
The red seat belt
warning lamp flashes
and an intermittent
audible warning
sounds.GRisk of injury
The driver or front passenger has not fastened their seat belt. In
addition, you are driving faster than 15 mph (25 km/h) or you have
briefly driven faster than 15 mph (25 km/h).
XFasten your seat belt ( Y page 55).
The warning lamp goes out and the intermittent warning tone
ceases.GRisk of injury
There are objects on the front-passenger seat. In addition, you are
driving faster than 15 mph (25 km/h) or you have briefly driven
faster than 15 mph (25 km/h).
XRemove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out and the intermittent warning tone
ceases.
Safety systems
ProblemPossible causes/consequences and M Solutions$ (USA only)
J (Canada only)
The red brake system
warning lamp comes on
while the engine is
running. A warning tone
also sounds.GRisk of accident
There is not enough brake fluid in the brake fluid reservoir.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.XEngage the parking brake.XConsult a qualified specialist workshop immediately.XObserve the additional display messages in the multifunction
display.
Do not add brake fluid. This will not correct the malfunction.
GWARNING
Driving with the brake warning lamp illuminated can result in an accident. Have your brake system
checked immediately if the brake warning lamp stays on. Do not add brake fluid before checking
the brake system.
Overfilling the brake fluid reservoir can result in spilling brake fluid on hot engine parts and the
brake fluid catching fire. You can be seriously burned.
Warning and indicator lamps in the instrument cluster259On-board computer and displaysZ

Useful information ............................268
Loading guidelines ............................268
Stowage areas .................................. 268
Features ............................................. 282267Stowing and features

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops ( Y page 24).
Loading guidelines
GWARNING
Always fasten items being carried as securely
as possible. Use cargo tie-down rings and
fastening materials appropriate for the weight
and size of the load.
In an accident, during hard braking or sudden
maneuvers, loose items will be thrown around
inside the vehicle. This can cause injury to
vehicle occupants unless the items are
securely fastened in the vehicle.
To help avoid personal injury during a collision
or sudden maneuver, exercise care when
transporting cargo. Do not pile luggage or
cargo higher than the seat backrests.
The cargo compartment is the preferred place
to carry objects. Always use cargo tie-down
rings, and if so equipped, always use the cargo
net when transporting cargo.
Never drive a vehicle with the tailgate open.
Deadly carbon monoxide (CO) gases may
enter vehicle interior resulting in
unconsciousness and death.
The gross vehicle weight (GVW) is the vehicle
weight including fuel, vehicle tool kit, spare
wheel, installed accessories, vehicle
occupants and luggage/cargo.
The gross load limit and the gross vehicle
weight rating (GVWR) for your vehicle must
never be exceeded. The gross load limit and
the GVWR are specified on the vehicle
identification plate on the B-pillar of the
driver's door ( Y page 349).
The load must also be distributed so that the
weight on each axle never exceeds the gross
axle weight rating (GAWR) for the front and
rear axles. The specifications for GVWR and
GAWR are on the vehicle identification plate
on the B-pillar of the driver's door
( Y page 349).
Further information can be found in the
"Loading the vehicle" section ( Y page 349).
The handling characteristics of a laden
vehicle are dependent on the distribution of
the load within the vehicle. For this reason,
you should observe the following notes when
transporting a load:
R position heavy loads as far forwards as
possible and as low down in the cargo
compartment as possible.
R the load must not protrude above the upper
edge of the seat backrests.
R always place the load against the rear or
front seat backrests. Make sure that the
seat backrests are securely locked into
place.
R hook in the cargo net when loading.
R always place the load behind unoccupied
seats if possible.
R secure the load with sufficiently strong and
wear-resistant tie down. pad sharp edges
for protection.
Stowage areas
Stowage compartments
Important safety notes
GWARNING
To help avoid personal injury during a collision
or sudden maneuver, exercise care when
storing objects in the vehicle. Put luggage or
cargo in the cargo compartment if possible.
268Stowage areasStowing and features

Do not pile luggage or cargo higher than the
seat backrests.
If so equipped, always use the cargo net when
transporting cargo. The cargo net cannot
secure hard or heavy objects.
Parcel nets cannot secure hard or heavy
objects.
Keep compartment lids closed. This will help
to prevent stored objects from being thrown
about and injuring vehicle occupants during
R braking
R vehicle maneuvers
R an accident
Stowage compartments in the front
Glove box
XTo open: pull handle : and open glove box
flap ;.XTo close: fold glove box flap ; upwards
until it engages.
The glove box can only be locked and
unlocked using the mechanical key.
1Glove box unlocked2Glove box locked
Stowage compartment in the center
console
XTo open: briefly press marking ;.XTo close: push stowage compartment :
in the direction of the arrow until it
engages.
Stowage compartment under the armrest
i The º (Y page 290) Roadside
Assistance call button and
E (Y page 290) MB Info call button are
located in the stowage compartment under
the armrest.
Stowage areas269Stowing and featuresZ

XTo open: pull handle : and fold the
armrest upwards.
Coin holders = are located in front of
stowage compartment ;.
Stowage compartments in the rear
Stowage compartment in the rear center
console
XTo open: briefly press the stowage
compartment marking.
i Depending on the vehicle's equipment,
there may be open stowage spaces above
and below the stowage compartment.
Stowage pockets
GWARNING
Storage bags are intended for storing light-
weight items only.
Heavy objects, objects with sharp edges or
fragile objects may not be transported in the
storage bag. In an accident, during hard
braking, or sudden maneuvers, they could be
thrown around inside the vehicle and cause
injury to vehicle occupants.
Storage bags cannot protect transported
goods in the event of an accident.
Storage bags are located in the rear
compartment on the driver's and front-
passenger seat backrests.
Parcel nets
GWARNING
Vehicles with Occupant Classification System
(OCS)
Do not place objects with a combined weight
of more than 4.4 lbs (2 kg) into the parcel net
on the back of the front passenger seat.
Otherwise, the OCS may not be able to
properly approximate the occupant weight
category.
GWARNING
Parcel nets are intended for storing light-
weight items only, such as road maps, mail,
etc.
Heavy objects, objects with sharp edges, or
fragile objects may not be transported in the
parcel nets. In an accident, during hard
braking, or sudden maneuvers, they could be
thrown around inside the vehicle and cause
injury to vehicle occupants.
Parcel nets cannot protect transported goods
in the event of an accident.
Parcel nets are located in the front-passenger
footwell and on the back of the driver's and
the front-passenger seat.
Enlarging the cargo compartment
Important safety notes
GWARNING
When expanding the cargo volume, always
fully fold the corresponding seats and, if so
270Stowage areasStowing and features

equipped, always use the cargo net when
transporting cargo.
Unless you are transporting cargo, the seat
backrests must remain properly locked in the
upright position.
In an accident, during hard braking or sudden
maneuvers, loose items will be thrown around
inside the vehicle. This can cause injury to
vehicle occupants unless the items are
securely fastened in the vehicle.
Always use the cargo tie-down rings.GWARNING
Never drive a vehicle with the tailgate open.
Deadly carbon monoxide (CO) gases may
enter vehicle interior resulting in
unconsciousness and death.
! Release and fold the seat cushion
upwards before folding the rear bench seat
forward. Otherwise, the backrests may be
damaged.
When the backrest is folded forwards, the
front seats cannot be moved to their
rearmost position. Otherwise, the front
seats and the rear bench seat could be
damaged.
The left-hand and right-hand backrests in the
second row of seats can be folded forwards
separately to increase the cargo
compartment capacity. On vehicles with a
third row of seats, you must fold down the
third row of seats beforehand (Y page 104) to
obtain maximum cargo compartment
enlargement.
Folding the rear bench seat forwards
i If the driver's or front-passenger seat is
set for a larger person, it may not be
possible to fold the rear bench seat
forwards. In this case, move the front seats
as far forward as possible.
XMove the head restraints to the lowest
position ( Y page 102).XPull release loop : of seat cushion ;.XFold seat cushion ; upwards.XPull release catch = in the direction of the
arrow.
The backrest is released.
! The backrest is heavy. Therefore, take
care when folding it down. Make sure that
the head restraints are pushed all the way
in so that the backrests and seat cushions
are not damaged.
XFold the backrest forwards until it engages
in the cargo compartment position.Stowage areas271Stowing and featuresZ

XGuide seat belts ; under respective
clips :.
Folding the rear bench seat back
XPull release catch = upwards.XFold backrest ; backwards until it
engages, making sure not to trap the seat
belts while doing so.XFold seat cushion : backwards and push
until you hear it engage.XPull up and adjust the head restraints if
necessary ( Y page 102).Securing cargo
Cargo tie-down rings
Observe the following notes on securing
loads:
R secure the load using the cargo tie down
rings.
R do not use elastic straps or nets to secure
a load, as these are only intended as an
anti-slip protection for light loads.
R do not route tie downs across sharp edges
or corners.
R pad sharp edges for protection.
Footwell of the second row of seats
There is one cargo tie-down ring : in the
footwell behind the driver’s seat and one in
the footwell behind the front-passenger seat.
Cargo compartment
There are four cargo tie down rings : in the
cargo compartment.
272Stowage areasStowing and features