wheel MERCEDES-BENZ GL 2012 Repair Manual

Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
If your brake system is subject only to
moderate loads, you should test the
functionality of your brakes at regular
intervals by pressing firmly on the brake pedal
at high speeds. This improves the grip of the
brake pads.GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
You can find a description of Brake Assist
(BAS) on ( Y page 69).
Parking brake
If you drive on wet roads or dirt-covered
surfaces, road salt and/or dirt could get into
the parking brake.
In order to prevent corrosion and a reduction
in the braking power of the parking brake,
observe the following:
R Gently depress the parking brake from time
to time before beginning the journey.
R Drive a distance of approximately 110 yds
(100 m) with a maximum speed of 12 mph
(20 km/h).
GWARNING
While performing this procedure please
assure that the vehicle is stopped before
applying the parking brake. Otherwise the
rear wheels could lock up. You could lose
control of the vehicle and cause an accident.
In addition, the vehicle's brake lights do not
light up when the parking brake is engaged.
Make sure not to endanger any other road
users when you engage the parking brake.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning occurring, even if:
R you drive at low speeds.
R the tires have adequate tread depth.
For this reason, in the event of heavy rain or
in conditions in which hydroplaning can occur
you must drive in the following manner:
R reduce your speed
R avoid ruts
R brake carefully
Driving on flooded roads
! Do not drive through flooded areas.
Check the depth of any water before driving
through it. Drive slowly through standing
water. Otherwise, water may enter the
vehicle interior or the engine compartment.
This can damage the electronic
components in the engine or the automatic
transmission. Water can also be drawn in
by the engine's air suction nozzles and this
can cause engine damage.
i Set the raised level before driving through
a stretch of standing water.
Off-road fording
:Fording depthDriving tips171Driving and parkingZ

conditions. Only these tires will allow driving
safety systems such as ABS and ESP ®
to
function optimally in winter, as these tires
have been designed specifically for driving on
snow.
Use M+S tires of the same make and tread on
all wheels to maintain safe handling
characteristics.GWARNING
M+S tires with a tread depth of less than 1
/ 6
inch (4 mm) must be replaced immediately.
They are no longer suitable for use in winter.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
Once you have mounted the winter tires:
XCheck the tire pressures ( Y page 345).XRestart the tire pressure monitor
( Y page 347).GWARNING
If you use your spare wheel when M+S tires
are mounted on the other wheels, be aware
that the difference in tire characteristics
impairs cornering ability and reduces driving
stability. Adapt your driving style accordingly.
Have the spare wheel replaced by a normal
wheel with an M+S tire at the nearest
Mercedes-Benz Center.
Snow chains
For safety reasons, Mercedes-Benz
recommends that you only use snow chains
which have been specially approved for your
vehicle by Mercedes-Benz, or are of a
corresponding standard of quality.
! Vehicles with the Adaptive Damping
System (ADS): do not drive in ADS SPORT
mode if snow chains have been mounted.
The vehicle may otherwise be damaged.
! There is not enough space for snow
chains on some wheel sizes. Observe the
information under "Tires and wheels" in the
"Technical Data" section to avoid damage
to the vehicle or the wheels.
R Only use snow chains when driving on
roads completely covered by snow. Do not
exceed the maximum permissible speed of
30 mph (50 km/h). Remove the snow
chains as soon as possible when you are no
longer driving on snow-covered roads.
R Local regulations may restrict the use of
snow chains. Applicable regulations must
be observed if you wish to mount snow
chains.
R Snow chains must not be mounted on
emergency spare wheels.
If you intend to mount snow chains, please
bear the following points in mind:
R you may not attach snow chains to all
wheel-tire combinations; see the
information under "Wheel and tire
combinations" in the "Wheels and tires"
section.
R mount snow chains only in pairs and only
to the rear wheels. Observe the
manufacturer's installation instructions.
! If snow chains are mounted on the front
wheels, the snow chains could grind
against the bodywork or components of the
chassis. This could result in damage to the
vehicle or the tires.
! Vehicles with steel wheels: if you wish
to install snow chains to steel wheels, make
sure that you remove the respective
wheels' hubcaps first. The hubcaps may
otherwise be damaged.
i You may wish to deactivate
ESP ®
(Y page 69) when pulling away with
snow chains mounted. This way you can
allow the wheels to spin in a controlled
manner, achieving an increased driving
force (cutting action).Driving tips173Driving and parkingZ

Slippery road surfacesGWARNING
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
GWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of control loss.
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km/h) vehicle
steering is adversely affected by the Off-road
ABS.
Drive particularly carefully on slippery road
surfaces. Avoid sudden acceleration, steering
and braking maneuvers. Do not use cruise
control.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
XShift the transmission to position N.
i
For more information on driving with
snow chains, see ( Y page 173).
GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
Off-road driving
Important safety notes
GWARNING
Grains of sand, particles of dirt and other
abrasive materials can enter the brake
system. This can lead to excessive wear and
unpredictable braking efficiency.
After the brakes have been exposed to dirty
conditions, have them checked and cleaned
at a qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center.
Otherwise, there is a risk that braking power
may be insufficient in the event of an
emergency, or that the braking effect may be
unpredictable.GWARNING
Do not load items on the crossbars. It may
cause instability during some maneuvers
which could result in an accident.
Drive slowly in unknown terrain. This will
make it easier to recognize unexpected
obstacles and avoid damage to the vehicle.
To help avoid the vehicle rolling over, never
turn it around on steep inclines. If the vehicle
cannot complete the attempted climb, back it
down in reverse gear.
Do not drive along the side of a slope. The
vehicle might otherwise rollover. If in doing so
the vehicle begins to show a tendency to roll,
immediately steer into a line of gravity
(straight up or downhill).
Never let the vehicle roll backwards in idle.
You may lose control of the vehicle if you use
only the service brake. For information on
driving downhill, see "Driving downhill".
GWARNING
Please be aware that by raising the vehicle
level, the center of gravity also rises.
Therefore, always ensure that the vehicle
level is as low as possible. With higher ride
height the ESP ®
may activate earlier in certain
situations.
GWARNING
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure before continuing your trip. Driving
with reduced tire inflation pressure increases
174Driving tipsDriving and parking

the risk of losing control of the vehicle and
rolling over.
General information
Read this section carefully before driving your
vehicle off-road. Practice by driving over more
gentle off-road terrain first.
Familiarize yourself with the characteristics
of your vehicle and the gear shift operation
before driving through difficult terrain.
The following driving systems are specially
adapted to off-road driving:
R off-road drive program (for vehicles without
Off-Road Pro engineering package)
( Y page 206)
R LOW RANGE off-road gear ( Y page 206)
R off-road ABS ( Y page 69)
R off-road 4ETS ( Y page 70)
R off-road ESP ®
(Y page 71)
R hill start assist
R differential locks ( Y page 208)
R DSR (Downhill Speed Regulation)
( Y page 204)
Observe the following notes:
R Stop your vehicle and, if necessary, select
the off-road drive program (Y page 206) or
the LOW RANGE off-road gear
( Y page 206) before driving off-road.
R Select a vehicle level suitable for the off-
road terrain. Make sure there is always
sufficient ground clearance to prevent
damage to the vehicle.
R Activate the differential locks.
R Check that items of luggage and loads are
stowed safely and are well secured
( Y page 272).
R Always keep the engine running and in gear
when driving on a downhill gradient.
Activate DSR ( Y page 204).
R Always keep the doors, tailgate, windows
and sliding sunroof closed while driving.
R Adapt your speed to the terrain. The
rougher, steeper or more ruts on the
terrain, the slower your speed should be.
R Drive slowly and at an even speed through
the water. Ensure that a bow wave does not
form as you drive.
R Drive with extreme care on unknown off-
road routes where visibility is poor. For
safety reasons, get out of the vehicle first
and survey the off-road route.
R Look out for obstacles such as rocks, holes,
tree stumps and furrows.
R Check the depth of water before fording
rivers and streams.
R When fording, do not stop and do not
switch off the engine.
R On sand, drive quickly to overcome the
rolling resistance. Otherwise, the vehicle
could dig itself into the sand.
R Do not jump with the vehicle as this will
interrupt the vehicle's propulsion.
R Always keep the engine running and in gear
when driving on a slope.
R Do not shift the automatic transmission to
transmission position N.
Checklist before driving off-roadXEngine oil level: check the engine oil and
top it up if necessary.
The vehicle can only guarantee a smooth
supply of oil on steep stretches if there is a
sufficient level of engine oil.
! If the engine oil warning lamp lights up
while the vehicle is in motion, stop the
vehicle in a safe place as soon as possible.
Check the engine oil level. The engine oil
warning lamp warning must not be ignored.
Continuing the journey while the symbol is
displayed could lead to engine damage.
XWheel-changing tool kit: check that the
jack is working and make sure you have theDriving tips175Driving and parkingZ

wheelbrace, a robust tow cable and a
folding spade in the vehicle.XWheels and tires: check the tire tread
depth and tire pressure. A table with the
recommended tire pressures can be found
on the B-pillar on the driver's side of your
vehicle.XCheck for damage and remove any foreign
objects, e.g. small stones, from the
wheels/tires.XReplace any missing valve caps.XReplace dented or damaged wheels.XRims: dented or bent rims can result in a
loss of tire pressure and damage the tire
bead. Therefore, check your rims before
driving off-road and replace them as
required.
Checklist after driving off-road
GWARNING
If you notice sudden significant vibrations or
unusual handling performance or if you
suspect that damage has occurred to the
vehicle, you should activate the hazard
warning lamps, gently reduce speed and
carefully head for an area that is located at a
safe distance from the road.
Check the tires and the underside of the
vehicle for damage. If the vehicle seems
unsafe, have the vehicle towed away to the
nearest Mercedes-Benz Center or tire dealer
to be repaired.
Driving over rough terrain places greater
demands on your vehicle than driving on
normal roads. After driving off-road, check
the vehicle. This allows you to detect damage
promptly and reduce the risk of an accident
to yourself and other road users.
XDeactivate the off-road drive program
( Y page 206) or the LOW RANGE off-road
gear ( Y page 206).XDeactivate DSR ( Y page 204).XSet the differential lock setting to AUTO on
the selector wheel ( Y page 208).XLower the vehicle level again to a level
suitable to the road conditions, e.g. to the
highway/high-speed level.XClean the headlamps and rear lights and
check for damage.XClean the front and rear license plates.XClean wheels/tires, wheel mounting and
underbody with a water jet, check them for
foreign objects and damage and rectify this
as required.XAfter the trip, examine without fail the
entire undercarriage, wheels, tires, brakes,
bodywork structure, steering, chassis and
exhaust system for damage.XCheck whether twigs or other parts of
plants have become trapped. These
increase the risk of fire and can damage
fuel pipes, brake hoses or the rubber
bellows of the axle joints and propeller
shafts.XAfter driving for extended periods across
sand, mud, gravel, water or in similarly dirty
conditions, have the brake discs, wheels,
brake pads/linings and axle joints checked
and cleaned.XIf you detect strong vibrations after off-road
travel, check for foreign objects in the
wheels and drive train and remove them if
necessary. Foreign objects can disturb the
balance and cause vibrations.XTest the brakes.
Driving on sand
GWARNING
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure before continuing your trip. Driving
with reduced tire inflation pressure increases
the risk of losing control of the vehicle and
rolling over.
176Driving tipsDriving and parking

Observe the following rules when driving on
sand:
R select a higher vehicle level.
R avoid high engine speeds.
R select a shift range appropriate to the
terrain.
R drive quickly to overcome the rolling
resistance. Otherwise, the vehicle could dig
itself into the sand.
R drive in the tracks of other vehicles if
possible. Make sure that the ruts are not
too deep, that the sand is firm enough and
that your vehicle has sufficient ground
clearance.
Ruts and gravel roads
Observe the following rules when driving
along ruts in off-road terrain or on roads with
loose gravel:
! Check that the ruts are not too deep and
that your vehicle has sufficient clearance.
Otherwise, your vehicle could be damaged
or bottom out and get stuck.
R select the off-road drive program
( Y page 206) or the LOW RANGE off-road
gear ( Y page 206).
R select a higher vehicle level.
R avoid high engine speeds.
R select shift range 1.
R drive slowly.
R where ruts are too deep, drive with the
wheels of one side on the center grassy
area, if possible.
Driving over obstacles
! Obstacles could damage the floor of the
vehicle or components of the chassis. Ask
passengers for guidance when driving over
large obstacles. The passenger should
always keep a safe distance from the
vehicle when doing so in order to avoid
injury as a result of unexpected vehicle
movements. After driving off-road or over
obstacles, check the vehicle for possible
damage, especially to the underbody and
the components of the chassis.
Observe the following rules when driving over
tree stumps, large stones and other
obstacles:
R select the off-road drive program
( Y page 206) or the LOW RANGE off-road
gear ( Y page 206).
R avoid high engine speeds.
R select shift range 1.
R drive very slowly.
R try to drive straight over the center of
obstacles: front wheel first, then rear
wheel.
Driving tips177Driving and parkingZ

GWARNING
Never turn the vehicle around on steep inclines. The vehicle might roll over. If the vehicle cannot
complete the attempted climb, back it down in reverse gear.
i Hill start assist will aid you when pulling away on a hill.
For more information, see "Hill start assist" ( Y page 151).
Maximum gradient-climbing capability
For good road surface conditions, the
maximum gradient-climbing capability is
100%, which corresponds to an approach/
departure angle of 45°. Note that the
vehicle's gradient-climbing capability
depends on the off-road conditions.
Accelerate carefully and make sure that the
wheels do not spin when driving on steep
terrain.
i If the load on the front axle is reduced
when pulling away on a steep uphill slope,
the front wheels have a tendency to spin.
4ETS recognizes this and brakes the
wheels accordingly. The rear wheel torque
is increased, making it easier to drive off.
i Vehicles with the Enhanced Off-Road
Package have a differential lock for the
transfer case and a differential lock for the
rear axle to improve vehicle traction.
Brow of hill
When driving up an uphill gradient, slightly
reduce pressure on the accelerator
immediately before reaching the brow of the
hill. Use the vehicle's own impetus to drive
over the top of the hill.
This style of driving prevents:
R the vehicle from lifting off the ground on the
brow of a hill
R loss of traction
R the vehicle from traveling too quickly down
the other side
Driving downhill
R Drive slowly.
R Do not drive at an angle down steep
inclines. Steer into the line of fall and drive
with the front wheels aligned straight.
Otherwise, the vehicle could slip sideways,
tip and rollover.
R Before tackling steep downhill gradients,
select shift range 1.
R Activate DSR. If this is not sufficient, brake
gently. When doing so, make sure that the
vehicle is facing in the direction of the line
of fall.
R Check that the brakes are working normally
after a long downhill stretch.
i The special off-road ABS setting enables
a precise, brief and repeated locking of the
front wheels, causing them to dig into the
loose earth. Be aware that the front wheels
easily skid across the ground surface if
completely braked and therefore lose their
ability to steer.
Driving systems
Cruise control
Important safety notes
Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer, you must
select shift range 1, 2 or 3 in good time. By
doing so, you will make use of the braking
effect of the engine, which relieves the load
on the brake system and prevents the brakes
from overheating and wearing too quickly.
Driving systems179Driving and parkingZ

Use cruise control only if road and traffic
conditions make it appropriate to maintain a
steady speed for a prolonged period. You can
set any road speed above 20 mph
(30 km/h).GWARNING
The cruise control is a convenience system
designed to assist the driver during vehicle
operation. The driver is and must always
remain responsible for the vehicle's speed
and for safe brake operation.
Only use the cruise control if the road, traffic,
and weather conditions make it advisable to
travel at a constant speed.
R The use of the cruise control can be
dangerous on winding roads or in heavy
traffic because conditions do not allow safe
driving at a constant speed.
R The use of the cruise control can be
dangerous on slippery roads. Rapid
changes in tire traction can result in wheel
spin and loss of control.
R Deactivate the cruise control when driving
in fog.
The "Resume" function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
GWARNING
When cruise control brakes, the brake pedal
is pulled back (i.e. operated automatically).
The area around the pedal must not be
blocked by obstacles:
R Do not place any objects in the footwell.
R Ensure that floormats and carpets are fixed
securely. In particular, do not place several
floormats on top of one another.
R Do not place your foot under the brake
pedal, as it could become trapped.
Non-compliance could lead you to cause an
accident in which you and/or others could be
seriously injured.
i Cruise control should not be activated
during off-road driving.
Cruise control lever:To store the current speed or a higher
speed;To store the current speed or a lower
speed=To deactivate cruise control?To store the current speed or to call up
the last stored speed
When you activate cruise control, the stored
speed is shown in the status indicator of the
multifunction display:
R USA only: e.g. Cruise 55 Miles
R Canada only: e.g. ¯90 Km/h
Storing and maintaining the current
speed
You can store the current speed if you are
driving faster than 20 mph (30 km/h).
XAccelerate the vehicle to the desired
speed.XBriefly press the cruise control lever
up : or down ; to the pressure point.XRemove your foot from the accelerator
pedal.
Cruise control is activated. The vehicle
automatically maintains the stored speed.
i Cruise control may be unable to maintain
the stored speed on uphill gradients. The
stored speed is resumed when the gradient
evens out. Cruise control maintains the
180Driving systemsDriving and parking

conditions make it advisable to travel at a
constant speed.GWARNING
Use of the Distronic can be dangerous on
slippery roads. Rapid changes in tire traction
can result in wheel spin and loss of control.
The Distronic does not function in adverse
sight and distance conditions. Do not use the
Distronic during conditions of fog, heavy rain,
snow or sleet.
GWARNING
The Distronic cannot take weather conditions
into account. Switch off the Distronic or do
not switch it on if:
R roads are slippery or covered with snow or
ice. The wheels could lose traction while
braking or accelerating, and the vehicle
could skid.
R the Distronic system sensor cover is dirty
or visibility is diminished due to snow, rain
or fog, for example. The distance control
system functionality could be impaired.
Always pay attention to surrounding traffic
conditions even while the Distronic is
switched on. Otherwise, you may not be able
to recognize dangerous situations until it is
too late. This could cause an accident in which
you and/or others could be injured.
GWARNING
The "Resume" function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
GWARNING
Close attention to road and traffic conditions
is imperative at all times, regardless of
whether or not the Distronic is activated.
Use of the Distronic can be dangerous on
winding roads or in heavy traffic because
conditions do not allow safe driving at a
constant speed.
The Distronic will not react to stationary
objects in the roadway (e.g. a stopped vehicle
in a traffic jam or a disabled vehicle). The
Distronic will also not respond to oncoming
vehicles.
Switch off the Distronic
R when changing from the left to the right
lane if vehicles are moving more slowly in
the left lane
R when entering a turn lane or highway off
ramp
R in complex driving situations, such as in
highway construction zones
In these situations, the Distronic will continue
to maintain the set speed unless deactivated.
The Distronic is designed and intended only
to maintain a set speed and keep a set
distance from moving objects in front of it.
i USA only:
This device has been approved by the FCC
as a “Vehicular Radar System”. The radar
sensor is intended for use in an automotive
radar system only. Removal, tampering, or
altering of the device will void any
warranties, and is not permitted by the
FCC. Do not tamper with, alter, or use in
any non-approved way.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.Driving systems183Driving and parkingZ

Cruise control lever:To store the current speed or a higher
speed;To store the current speed or a lower
speed=To deactivate DISTRONIC?To store the current speed or to call up
the last stored speed
Switching on DISTRONIC, storing and
maintaining the current speed
GWARNING
The vehicle can be braked when DISTRONIC
is activated. For this reason, deactivate
DISTRONIC if the vehicle is to be set in motion
by other means (e.g. in a car wash or by
towing).
You can activate DISTRONIC in the following
circumstances:
R if the engine has been started and you have
been driving for up to two minutes
R while driving, except if you brake
R if the parking brake is not applied
R if ESP ®
is activated
R if the transmission is in position D
Activating while driving
When driving at speeds below 20 mph
(30 km/h) , you can only activate DISTRONIC
PLUS if the vehicle in front has been detected
and is shown in the multifunction display. If
the vehicle in front is not shown in the
multifunction display and is no longer being
detected, because it has changed lanes, for
example, DISTRONIC is deactivated and you
hear a warning tone.XBriefly pull the cruise control lever towards
you ? or press it up : or down ; to the
pressure point.
DISTRONIC is activated.XKeep the cruise control lever pressed
up : or down ; until the desired speed
is set.XRemove your foot from the accelerator
pedal.
Your vehicle adapts its speed to that of the
vehicle in front, but only up to the desired
stored speed.
i You can use the cruise control lever to set
the stored speed and the thumbwheel on
the cruise control lever to set the specified
minimum distance ( Y page 186).
i If you do not fully release the accelerator
pedal, the DISTRONIC Override message
appears in the multifunction display. The
set distance to a slower-moving vehicle in
front will then not be maintained. You will
be driving at the speed you determine by
the position of the accelerator pedal.
Driving
If there is no vehicle in front, DISTRONIC
operates in the same way as cruise control.
If a slower-moving vehicle is detected in front,
DISTRONIC causes your vehicle to brake and
maintain the preset distance to the vehicle in
front.
If DISTRONIC detects a faster-moving vehicle
in front, it increases the driving speed, but
only up to the desired speed you have stored.
GWARNING
If you depress the brake pedal, DISTRONIC is
deactivated. DISTRONIC will then no longer
brake your vehicle. In such cases, control the
distance from vehicles traveling in front with
the brake alone. You could otherwise cause
an accident and thereby injure yourself and
others. The driver remains fully responsible
184Driving systemsDriving and parking