2012 MERCEDES-BENZ GL-Class stop start

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.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 tow hitch
- 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
Trailer towing211Driving and parkingZ

Telephone menu
Introduction
You can establish a Bluetooth ®
connection to
COMAND (see the separate operating
instructions).
GWARNING
A driver's attention to the road must always
be his/her primary focus when driving. For
your safety and the safety of others, we
recommend that you pull over to a safe
location and stop before placing or taking a
telephone call. If you choose to use the
telephone while driving, please use the hands-
free device and only use the telephone when
weather, road and traffic conditions permit.
Some jurisdictions prohibit the driver from
using a mobile phone while driving a vehicle.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h ), your vehicle is
covering a distance of 44 feet (approximately
14 m) every second.
XSwitch on the mobile phone and COMAND
(see the separate operating instructions).XPress the V or U button on the
steering wheel to select the Telephone
menu.
You will see one of the following display
messages in the multifunction display:
R Ready or the name of the network provider:
the mobile phone has found a network and
is ready to receive.
R No Service : no network is available, or the
mobile phone is searching for a network.
Accepting a call
If someone calls you when you are in the
Telephone menu, a display message appears
in the multifunction display, for example:
XPress the 6 button on the steering
wheel to accept an incoming call.
If you are not in the Telephone menu, you can
still accept a call.
Rejecting or ending a call
XPress the ~ button on the steering
wheel.
If you are not in the Telephone menu, you can
still accept a call.
Dialing a number from the phone book
You can enter new telephone numbers into
the phone book via the mobile phone (see the
separate operating instructions). If your
mobile phone is operational, you can select
and dial a number from the phone book at any
time.
XPress the V or U button on the
steering wheel to select the Telephone
menu.XPress the & or * button to select the
desired name.
To start scrolling rapidly, press and hold the
& or * button for longer than one
second.XPress 6 to start dialing.
or
XIf you do not want to make a call, press the
~ button.
Redialing
The on-board computer saves the last names
or numbers dialed in the redial memory.
230Menus and submenusOn-board computer and displays

Display messagesPossible causes/consequences and M Solutions?
Coolant Stop car,
switch engine offThe coolant is too hot.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.XWait until the display message disappears before restarting the
engine. Otherwise, there is a risk of engine damage.XPay attention to the coolant temperature display.XIf the temperature increases again, visit a qualified specialist
workshop immediately.The poly-V-belt may have torn.XPull 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:
XWait until the display message disappears before restarting the
engine. Otherwise, there is a risk of engine damage.XPay attention to the coolant temperature display.XVisit a qualified specialist workshop.GWARNING
Driving when your engine is overheated can cause some fluids which may have leaked into the
engine compartment to catch fire. You could be seriously burned.
Steam from an overheated engine can cause serious burns which can occur just by opening the
engine hood. Stay away from the engine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until the engine has cooled down.
! If the coolant temperature exceeds 248 ‡(120 †) do not continue driving. The engine will
otherwise be damaged.
Display messages245On-board computer and displaysZ

TiresGWARNING
Do not drive with a flat tire. A flat tire affects the ability to steer or brake the vehicle. You may
lose control of the vehicle. Continued driving with a flat tire will cause excessive heat build-up
and possibly a fire.
GWARNING
Follow recommended tire inflation pressures.
Do not underinflate tires. Underinflated tires wear excessively and/or unevenly, adversely affect
handling and fuel economy, and are more likely to fail from being overheated.
Do not overinflate tires. Overinflated tires can adversely affect handling and ride comfort, wear
unevenly, increase stopping distance, and result in sudden deflation (blowout) because they are
more likely to become punctured or damaged by road debris, potholes etc.
Display messagesPossible causes/consequences and M SolutionsTire Pressure
Check TiresGRisk of accident
The tire pressure loss warning system has detected a significant
loss in pressure.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XCheck the tires and, if necessary, change the wheel
( Y page 362).XCheck the tire pressures and, if necessary, set to the correct
tire pressure.XRestart the tire pressure loss warning system when the tire
pressure is correct ( Y page 345).Check tires,
then restart Run
Flat IndicatorThe tire pressure loss warning system generated a display
message and has not been restarted since.XSet the correct tire pressure in all four tires.XRestart the tire pressure loss warning system ( Y page 345).Run Flat Indicator
InoperativeThe tire pressure loss warning system is defective.XVisit a qualified specialist workshop.Tire pressure
displayed after
driving for a few
minutesThe tire pressure monitor is measuring the tire pressure.XDrive on.
The tire pressures appear in the multifunction display after you
have been driving for a few minutes.Tire Pressure
Monitor
InoperativeThe tire pressure monitor is defective.XVisit a qualified specialist workshop.252Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsTire Pressure
Monitor
Inoperative No
Wheel SensorsThe wheels mounted do not have a suitable tire pressure sensor.
The tire pressure monitor is deactivated.XMount wheels with suitable tire pressure sensors.
The tire pressure monitor is activated automatically after driving
for a few minutes.Check
Tire(s)GRisk of accident
The tire pressure in one or more tires has dropped significantly.
The wheel position is displayed in the multifunction display.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XCorrect the tire pressure ( Y page 347).XIf necessary, change a wheel ( Y page 362).Caution:
Tire DefectGRisk of accident
The tire pressure in one or more tires has dropped suddenly. The
wheel position is displayed in the multifunction display.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XIf necessary, change a wheel ( Y page 362).Tire Pressure(s)
Please CorrectThe tire pressure is too low in at least one of the tires or the tire
pressure difference between the wheels is too great.XCheck the tire pressures at the next opportunity. If necessary,
correct the tire pressure ( Y page 347).XRestart the tire pressure monitor ( Y page 349).Tire Pressure
Monitor
Wheel Sensor
MissingThere is no signal from the tire pressure sensor of one or several
wheels. The pressure of the affected tire is not displayed in the
multifunction display.XHave the defective tire pressure sensor replaced at a qualified
specialist workshop.Tire Pressure
Monitor
Currently
UnavailableDue to a source of radio interference, no signals can be received
from the wheel sensors. The tire pressure monitor is temporarily
malfunctioning.XDrive on.
The tire pressure monitor restarts automatically as soon as the
problem has been solved.Display messages253On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutionsh
Tire Pressure
Caution: Tire
DefectGRisk of accident
The tire pressure in one or more tires has dropped suddenly.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XIf necessary, change a wheel ( Y page 362).h
Tire Pressure
Check TiresGRisk of accident
The tire pressure in one or more tires has dropped significantly.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XIf necessary, change a wheel ( Y page 362).XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 347).h
Please correct the
tire pressuresThe tire pressure is too low in at least one of the tires or the tire
pressure difference between the wheels is too great.XCheck the tire pressures at the next opportunity. If necessary,
correct the tire pressure ( Y page 347).
Vehicle
Display messagesPossible causes/consequences and M SolutionsShift to P or N
to start engine.You have attempted to start the engine with the transmission in
position R or D.XShift the transmission to position P or N.Auxiliary Battery
MalfunctionThe auxiliary battery for the automatic transmission is no longer
being charged.XVisit a qualified specialist workshop at the next opportunity.XUntil then, set the automatic transmission to position P before
you switch off the engine.XBefore leaving the vehicle, apply the parking brake.Depress brake to
shift out of P.You have attempted to move the transmission selector lever to
position D, R or N without depressing the brake pedal.XDepress the brake pedal.254Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M Solutions+
Key Not Detected
(Red display message)The KEYLESS-GO key is not in the vehicle.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XLocate the KEYLESS-GO key.The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XOperate the vehicle with the SmartKey in the ignition lock.+
Key Not Detected
(White display
message)The KEYLESS-GO key cannot be detected at present.XChange the location of the key with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
XChange the location of the key with the KEYLESS-GO functions
in the vehicle.XOperate the vehicle with the SmartKey in the ignition lock.+
Key Detected in
VehicleThe KEYLESS-GO key has been detected inside the vehicle during
locking.XRemove the KEYLESS-GO key from the vehicle.+
Pull starting
button out then
insert key.The KEYLESS-GO key can continuously not be detected.XInsert the SmartKey into the ignition lock and turn it to the
desired position.XVisit a qualified specialist workshop.Display messages257On-board computer and displaysZ

indicated on the Tire and Loading Information placard or, if available, the tire inflation pressure
label, you should determine the proper tire inflation pressure for those tires.
As an added safety feature, your vehicle has been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pressure warning lamp when one or more of your tires
are significantly underinflated. Accordingly, when the low tire pressure warning lamp illuminates,
you should stop and check your tires as soon as possible, and inflate them to the proper pressure.
Driving on a significantly underinflated tire causes the tire to overheat and can lead to tire failure.
Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling
and stopping ability. Please note that the TPMS is not a substitute for proper tire maintenance,
and it is the driver's responsibility to maintain correct tire pressure, even if underinflation has
not reached the level to trigger illumination of the TPMS low tire pressure warning lamp.
Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when the
system is not operating properly. The TPMS malfunction indicator is combined with the low tire
pressure warning lamp. When the system detects a malfunction, the warning lamp will flash for
approximately one minute and then remain continuously illuminated. This sequence will continue
upon subsequent vehicle start-ups as long as the malfunction exists. When the malfunction
indicator is lit, the system may not be able to detect or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of reasons, including the installation of incompatible
replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning
properly. Always check the TPMS malfunction warning lamp after replacing one or more tires or
wheels on your vehicle to ensure that the replacement or alternate tires and wheels allow the
TPMS to continue to function properly.266Warning and indicator lamps in the instrument clusterOn-board computer and displays