2011 MERCEDES-BENZ GL350 BlueTEC parking brake

Differential lock
General notes
i Differential locks are available only in
vehicles with the Off-Road Pro engineering
package.
Your vehicle is equipped with the following:
R A differential lock for the transfer box: this
controls the balance between the front and
rear axles.
R A differential lock for the rear axle: this
controls the balance between the wheels
and the rear axle.
Differential locks improve the vehicle's
traction. 4ETS ( Y page 67)controls the
balance between the wheels on the front axle.
Information on "Off-road driving"; see
( Y page 173).
Information about the differential and
differential locks
When the vehicle is driving around a curve,
the wheels on the outside of the curve have
to cover a greater distance and therefore
have to turn faster than the wheels on the
inside. The differential, a transmission in the
drive train, balances these different rotational
speeds out, making cornering possible.
The disadvantage of a differential: the wheels
with the least grip are driven the hardest.
Example: one wheel on a driven axle is on a
snow-covered surface and therefore has no
traction. This wheel has the most driving
force, since the differential distributes most
of the force to the wheel with the least
resistance. The wheel on the opposite side of
this axle, which is on a solid surface and could
therefore enable traction, does not have any
driving force. 4ETS eliminates this
disadvantage and ensures good steerability
by braking the spinning wheel automatically
and thereby directing more force to the wheel
that is on a solid surface and can provide
traction.
ESP ®
and 4ETS are traction systems that are
ideally suited to road driving and driving on
easily negotiable off-road terrain. The LOW
RANGE off-road gear also improves off-road
capability.
Difficult off-road conditions require additional
measures, such as locking one or more
differentials. Your vehicle has two differential
locks: one (central) differential lock for the
transfer case and one differential lock for the
rear axle. Both differential locks can be
activated using the selector wheel on the
center console. When the (central)
differential for the transfer case is locked, the
speed of the front wheels is the same as the
speed of the rear wheels. When the
differential for the rear axle is locked, both of
the rear wheels turn at the same speed,
independent of their individual torques. Note
that activating the differential locks
significantly reduces the steerability of the
vehicle.
For your safety, the safety of others and to
prevent damage to the vehicle, the
differential locks must not be activated on
paved roads. Note that the differential
function is necessary when driving on paved
roads and that the differentials must never be
locked on paved roads. Otherwise, the
vehicle can no longer be steered. The
differential locks must therefore only be
activated when driving off-road, and then only
if activating the other driving systems (4ETS,
ESP ®
and LOW RANGE off-road gear) is no
longer sufficient.
Engaging the differential locks
! Drive off slowly when the differential
locks are engaged.
Function or performance tests may only be
performed on a 2-axle dynamometer. If you
wish to operate the vehicle on such a
dynamometer, please consult an
authorized Mercedes-Benz Center
beforehand. You could otherwise damage
the drive train or the brake system.
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Message in the multifunction display
Diff. Lock System Overheated -
Wait briefly.
The differential lock system has overheated
and briefly disengaged.XContinue driving.
The differential locks cool off and are soon
available once again.
Towing a trailer
Notes on towing a trailer
Important safety instructions
GWarning!
Failure to use proper equipment and driving
technique can result in a loss of vehicle
control when towing a trailer.
Improper towing or failure to follow the
instructions in this manual can result in
vehicle damage and/or serious personal
injury. Follow the guidelines below carefully
to assure safe trailer operation.
Contact an authorized Mercedes-Benz Center
should you require an explanation of
information contained in this manual.
General information
R Only install an approved trailer coupling on
your vehicle.
Further information on availability and on
installation is available from any authorized
Mercedes-Benz Center.
R The bumpers of your vehicle are not
suitable for installing detachable trailer
couplings.
R Do not install hired trailer couplings or
other detachable trailer couplings on the
bumpers of your vehicle.
R To reduce the risk of damage to the ball
coupling, remove it from the ball coupling
recess when not in use.
Coupling up a trailerGWarning!
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.
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
button or the vehicle level control system
when coupling/decoupling the trailer.
Observe the maximum permissible trailer
dimensions (width and length).
Most federal 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
coupling, not to the bumper or the axle.
Allow for enough play in the chains to
facilitate 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 federal state.
If the trailer detaches from the towing
vehicle, the safety switch applies the
trailer's brakes.
! Do not connect the trailer's brake system
(if featured) to the hydraulic brake system
of the towing vehicle, as the latter is
equipped 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.
i The vehicle's wiring harness features a
line to the brake indicator lamp.
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XMake sure that the automatic transmission
is set to position P.XApply the vehicle's parking brake.XStart the engine.XSelect highway level.XVehicles with the adaptive damping
system: set ADS to AUTO or COMF .XSwitch off the engine.XClose all doors and the tailgate.XCouple up the trailer.XEstablish all electrical connections.
i
Vehicles with the AIRMATIC package:
with a trailer attached, the vehicle will
always remain at highway level. When
coupling up a trailer, please observe the
following:
R if highway level has not been set
manually, the vehicle will automatically
sink to highway level as soon as it
reaches a speed of 5 mph (8 km/h).
R high-speed level is not available.
These restrictions apply to all accessories
powered through a connection to the trailer
power socket of your vehicle, e.g. a bicycle
carrier.
Towing a trailer
There are numerous legal requirements
concerning 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
residence 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,
stopping and reversing in a traffic-free
location.
R Before driving, check:
- the trailer coupling
- the safety switch for braked trailers
- the safety chains
- the electrical connections
- the lights
- the wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer features electronically
controlled 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
applicable) the trailer brakes are
functioning correctly.
R Bear in mind that the handling will be less
stable when towing a trailer than when
driving without one. Avoid sudden steering
movements.
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. Then
increase 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, or 1.
A lower gear and lower speed reduce the
risk of engine failure.210Towing a trailerDriving and parking
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ROn long and steep gradients that are
difficult to drive down in shift range 1,
switch to the off-road drive program or
engage the LOW GEAR off-road gear.
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
dramatically while the air-conditioning
system is switched on, switch off the air-
conditioning system.
Coolant heat can additionally be dissipated
by opening the windows and by setting the
blower fan and the interior temperature to
maximum.
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
additional distance beyond the vehicle you
are overtaking before returning to the
previous lane.
Decoupling a trailer
GWarning!
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.
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
button or the vehicle level control system
when coupling/decoupling the trailer.
XMake sure that the automatic transmission
is set to position P.XApply the vehicle's parking brake.XStart the engine.XClose all doors and the tailgate.XApply the trailer's parking brake.GWarning!
As soon as you disconnect the electrical
connection between the trailer and the
vehicle, the vehicle will lower. To help avoid
personal injury, make sure no one is near the
wheel housing or underneath the vehicle
before the electrical connection is
disconnected.
When you decouple the trailer, the vehicle is
temporarily raised because the springs are
relieved of load. Be especially careful during
this process, as you could otherwise injure
yourself and/or others. Make sure that any
persons remaining in the vehicle do not press
the switches for vehicle level control or the
ADS.
XDetach the trailer cable and decouple the
trailer.XDetach the trailer cable and decouple the
trailer.XSwitch off the engine.
Permissible trailer load and drawbar
noseweight
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
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Display messagesPossible causes/consequences and M SolutionsFront Passenger
Airbag Enabled
See Operator's
ManualThe front-passenger air bag is enabled during the journey,
although:
R there is a child, a small adult or an object weighing less than the
system's weight threshold is on the front-passenger seat.
R the front-passenger seat is unoccupied
The system may detect the additional weight of objects on the
seat or forces acting on the seat.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XSwitch off the ignition.XOpen the front-passenger door.XRemove the child and the child restraint system from the front-
passenger seat.XIf necessary, secure the child in a child restraint system on a
suitable rear seat.XMake sure that no forces are acting on the seat, such as:
R trapped books, bags, etc. lying on, behind or beside the seat
R head restraints pressing against the headliner
The system may otherwise detect these forces and interpret the
seat occupant's weight as greater than it actually is.XMake sure that the seat is unoccupied and has no objects placed
on it, close the front-passenger door, and switch on the ignition.
Observe the 42 indicator lamps (Y page 42) and the
multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the 42 indicator lamp must light up and remain lit.
When the indicator lamp is on, OCS ( Y page 42) has disabled
the front-passenger air bag.
R the display messages Front Passenger Airbag Enabled
See Operator's Manual or Front Passenger Airbag
Disabled See Operator's Manual must not appear in the
multifunction display. Wait for a period of at least 60 seconds
until the necessary system checks have been completed and to
make sure that the display messages do not appear in the
multifunction display.
If these conditions are met, the front-passenger seat can be
occupied again. Whether the 42 indicator lamp
remains lit or goes out depends on how OCS classifies the
occupant.
If the conditions are not met, the system is not operating correctly.
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Display messagesPossible causes/consequences and M SolutionsFront Passenger
Airbag Disabled
See Operator's
ManualThe front-passenger air bag is disabled during the journey even
though an adult or a person larger than a certain size is occupying
the front-passenger seat. If additional forces are applied to the
seat, the weight the system detects may be too low.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XSwitch off the ignition.XHave the occupant get out of the vehicle.XSet the seat higher ( Y page 96).XMake sure that no objects are exerting force on the seat, e.g.
books, bags, etc. lying under, behind or beside the seat. These
forces may otherwise cause the system to detect too low a
weight and interpret the seat occupant's weight as less than it
actually is.XMake sure that the seat is unoccupied and has no objects placed
on it, close the front-passenger door, and switch on the ignition.
Observe the 42 (Y page 42) indicator lamps and the
multifunction display and check the following:
Seat unoccupied and ignition switched on:
R the 42 indicator lamp must light up and remain lit.
When the indicator lamp is on, OCS ( Y page 42) has disabled
the front-passenger air bag.
R the display messages Front Passenger Airbag Enabled
See Operator's Manual or Front Passenger Airbag
Disabled See Operator's Manual cannot appear in the
multifunction display. Wait for a period of at least 60 seconds
until the necessary system checks have been completed and to
make sure that the display messages do not appear in the
multifunction display.
If these conditions are met, the front-passenger seat can be
occupied again. Whether the 42 indicator lamp
remains lit or goes out depends on how OCS classifies the
occupant.
If the conditions are not met, the system is not operating correctly.
XVisit a qualified specialist workshop immediately.GWarning
If the 42 indicator lamp remains lit with an adult occupant on the front-passenger
seat even after performing the above corrective steps, do not have any passenger use the front-
passenger seat until the system has been repaired.
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Display messagesPossible causes/consequences and M Solutions$
(USA only)
J
(Canada only)
EBV, ABS, ESP
Inoperative See
Operator's ManualGRisk of accident
EBD (Electronic Brake-force Distribution), ABS (Anti-lock Brake
System), ESP ®
(Electronic Stability Program) and therefore also
PRE-SAFE ®
are not available due to a malfunction. BAS (Brake
Assist) is also deactivated.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XDrive on carefully.XVisit a qualified specialist workshop immediately.#
Brake WearThe brake pads/linings have reached their wear limit.XVisit a qualified specialist workshop.$
(USA only)
!
(Canada only)
Release Parking
BrakeYou are driving with the parking brake engaged. A warning tone
also sounds.XRelease the parking brake.$
(USA only)
J
(Canada only)
Check Brake Fluid
LevelGRisk of accident
There is insufficient brake fluid in the brake fluid reservoir. In
addition, the red warning lamp $(USA only) or J (Canada
only) in the instrument cluster lights up and a warning tone sounds.
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.XDo not add brake fluid. This will not rectify the malfunction.GWarning
Driving with the message Check Brake Fluid Level displayed can result in an accident. Have
your brake system checked immediately.
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.
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Display messagesPossible causes/consequences and M Solutions?The engine fan is faulty.XAt coolant temperatures under 248 ‡(120 †), drive to the next
qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-start driving.#The battery is not being charged.
Possible causes are:
R a faulty alternator
R a torn poly-V-belt
R a malfunction in the electronicsXPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is OK:
XVisit a qualified specialist workshop.#
Battery/
Alternator Stop
VehicleThe battery is faulty.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.4
Check engine oil
level at next
refuelingThe oil level is too low.XCheck the oil level ( Y page 295).XIf necessary, add the engine oil ( Y page 296).XHave the engine checked for leaks if engine oil has to be added
more often than usual.
Information on approved engine oils can be obtained from any qualified specialist workshop
or on the Internet at http://www.mbusa.com (USA only).
! The oil level is too low. Avoid long journeys with too little engine oil. There is a risk of
engine damage.
The display messages and the corresponding symbol that indicate that the oil level is too
low must not be ignored.
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