2012 MERCEDES-BENZ GL differential

computer, the message disappears after
about five seconds.
The differential locks are not controlled
automatically. The steerability of the vehicle
is restricted considerably. Drive carefully and
accelerate gently for optimum traction.
! If the differential locks are activated
manually, the wheels scuff on the road
when cornering since the rotation
difference between the wheels is no longer
balanced out.
You can switch back to automatic mode at
any time. For safety reasons, the differential
locks are deactivated automatically at speeds
over 31 mph (50 km/h). If you stop the
vehicle and switch off the ignition for longer
than ten seconds, the differential locks
switch back to automatic mode.
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.
Trailer towing
Notes on towing a trailer
Important safety notes
GWARNING
When towing a trailer, incorrect equipment
and driving style could cause you to lose
control of the vehicle.
Towing incorrectly or not observing this
Operator's Manual could lead to damage to
the vehicle and/or serious injuries. Observe
the following guidelines to ensure safe trailer
towing.
Contact a Mercedes-Benz Center if you need
further explanation of the information
contained in this Operator's 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 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.
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.
210Trailer towingDriving and parking

Menus and submenus
Menu overview
The number of menus shown depends on the optional equipment in the vehicle.
Function:Standard display menu (Y page 220)
R tire pressure loss warning system (Canada only) ( Y page 345)
R tire pressure monitor (USA only) ( Y page 347)
R ASSYST PLUS service interval display ( Y page 305);Audio menu ( Y page 221)=Navigation menu (Y page 222)?Offroad menu (Y page 222)
R Level control ( Y page 189)
R Compass display ( Y page 296)
R Differential locks (status indicator) ( Y page 208)ADISTRONIC menu (Y page 187)BMessage memory 24
menu ( Y page 232)CSettings menu (Y page 223)DAdditional functions menu (Y page 228)24
The menu is only visible if there is a display message.Menus and submenus219On-board computer and displaysZ

XTo select the next/previous track:
briefly press the & or * button.XTo select a track from the track list
(rapid scrolling): press and briefly hold the
& or * button.
The current track will not be displayed in
audio AUX mode ( Auxiliary audio mode:
external audio source connected).
Operating video DVD
XSwitch on COMAND and select video DVD
(see the separate operating instructions).XPress the V or U button on the
steering wheel to select the Audio menu.
DVD changer display (example)
:Current DVD (for DVD changer);Current sceneXPress the & or * button to select a
scene.
Navigation system menu
Displaying navigation instructions
In the Navigation menu: the instructions
from the navigation system appear in the
multifunction display. For more information,
see the separate operating instructions.
XSwitch on COMAND (see the separate
operating instructions).XPress the V or U button on the
steering wheel to select the Navigation
menu.Route guidance inactive
The direction of travel appears in the
multifunction display. If the name of the
street is part of the navigation system data,
this will also be displayed.
Route guidance active
The multifunction display shows navigation
instructions, for example:
Off-road menu
Depending on your vehicle's optional
equipment, you can set the following current
settings to be shown in the Off-road menu:
R Level control ( Y page 189)
R compass ( Y page 296)
R differential locks ( Y page 208)
i Large buildings, power cables or powerful
transmission masts as well as metallic
objects on or in the vehicle may interfere
with the compass display.
XPress V or U on the steering wheel
to select the Offroad menu.222Menus and submenusOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsÆ
Being lowered Max.
12 MPHThe vehicle is being lowered from off-road level 3 to off-road level
2. 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) until off-road level 2
has been reached.8
Locking System
Inoperative
Service RequiredThe differential locks are defective.XDo not drive faster than 50 mph (80 km/h).XHave the vehicle checked at a qualified specialist workshop.8
Diff. Lock System
Overheated - Wait
briefly.The differential locks are too hot and have been disengaged.XDrive on carefully.XAllow the differential locks to cool down.
The differential locks reengage as soon as they have cooled
down.8
Stop vehicle,
engage parking
brakeA gearshift process has been canceled. LOW RANGE is in the
neutral position. There is no connection between the engine and
the drive wheels.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake. Do not continue driving under any
circumstances.XRepeat the gearshift process.Å
Service Required
If parked engage
pk. brakeLOW RANGE is malfunctioning.XDo not drive faster than 50 mph (80 km/h).XEngage the parking brake to park.XHave the vehicle checked at a qualified specialist workshop.Å
Max. Speed 25 MPHYou have exceeded the maximum speed for the gearshift process.XDrive slower.
The gearshift process is carried out.Å
Max. Speed 40 MPHYou have exceeded the maximum speed for the gearshift process.XDrive slower.
The gearshift process is carried out.Å
Shift briefly into
NYou have reduced the vehicle speed, but the automatic
transmission is not in position N.XBriefly shift the automatic transmission to position N.Display messages249On-board computer and displaysZ

Towing and tow-starting
Important safety notes
GWARNING
If you tow the vehicle, you must use a rigid
towing bar if:
R the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the power supply
or the vehicle's electrical system.
The power assistance for the steering and the
brake force booster do not work when the
engine is not running. You will need more
force to steer and brake, you may have to
depress the brake pedal with maximum force.
Before towing away, make sure that the
steering can be moved and is not locked.
If you tow or tow-start another vehicle, its
weight must not exceed the maximum
permissible gross vehicle weight of your
vehicle.
It is better to have the vehicle transported
than to have it towed.
! You may only tow the vehicle a maximum
distance of 30 miles (50 km). A towing
speed of 30 mph (50 km/h) must not be
exceeded.
For towing distances over 30 miles
(50 km), the vehicle must loaded onto a
transporter.
! Only secure the tow rope or tow bar at the
towing eyes. Otherwise, the vehicle could
be damaged.
! Do not use the towing eye for recovery,
as this could damage the vehicle. If in
doubt, recover the vehicle with a crane.
! When towing, pull away slowly and
smoothly. If the tractive power is too high,
the vehicles could be damaged.
! Do not tow with sling-type equipment.
This could damage the vehicle.
! When towing vehicles with KEYLESS-GO,
use the key instead of the Start/Stop
button. Otherwise, the automatic
transmission may shift to position P when
the driver's or front-passenger door are
opened, which could lead to damage to the
transmission.
! Vehicles with differential locks: make
sure that the differential locks are in
automatic mode. When towing, the
differential locks must not be switched on
by hand. This could otherwise damage the
transmission.
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised,
as doing so will damage the transmission.
If the vehicle has suffered transmission
damage, have it transported on a transporter
or trailer.
The automatic transmission must be in
position N when the vehicle is being towed.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the SmartKey to position 2 in
the ignition lock
R cannot shift the automatic transmission to
position N
i Before the vehicle is towed, switch off the
automatic locking feature ( Y page 226).
You could otherwise be locked out when
pushing or towing the vehicle.
Installing/removing the towing eye
Installing the towing eye
Vehicles with a trailer tow hitch: if possible
secure the towing device on the trailer tow
hitch ( Y page 210).
XRemove the towing eye from the vehicle
tool kit ( Y page 314).Towing and tow-starting331Breakdown assistanceZ