2012 MERCEDES-BENZ G-Class traction control

Differential locks
General information Differential locks improve the traction of the
vehicle.
G
WARNING
Never drive on firm road surfaces with
differential locks engaged. Never drive on
narrow bends
with front-axle differential locks
engaged. With differential locks engaged, the
vehicle's ability to steer is severely restricted
and the danger of accidents is therefore
higher.
Do not engage or disengage differential locks
while driving on a bend. The vehicle may
otherwise make a jerking movement. You
could thus lose control of the vehicle and
cause an accident.
If you select a differential lock, ABS, 4ETS,
ESP ®
and BAS will be deactivated.
Your vehicle is equipped with a differential
lock for:
R the transfer case: this controls the balance
between the front and rear axles.
R the rear axle: this controls the balance
between the wheels on the rear axle.
R the front axle: this controls the balance
between the wheels on the front axle.
! In order to avoid damage to the transfer
case, you must operate the vehicle on a
dynamometer (1-axle dynamometer) only
if:
R the axle not driven on is jacked up
or
R the corresponding propeller shaft is
disconnected
and
R the differential lock of the transfer case
is engaged.
Otherwise, the transfer case can be
damaged. Information about differentials and
differential locks When
the vehicle drives around a corner, the
wheels on

the outside of the bend must cover
a greater distance. Therefore, the wheels turn
more rapidly than on the inside. The
differential, a transmission in the drivetrain,
balances out the different rotational speeds
and therefore enables driving through bends.
The disadvantage of a differential is that more
power is transferred to the wheels that have
the least grip. Example: a wheel on a driven
axle stands on snow-covered ground and thus
has no traction. This wheel receives the
strongest driving power from the differential,
as the force progression takes the path of
least resistance. The opposite wheel on this
axle, however, which stands on firm ground
and could therefore allow propulsion,
receives no driving power. 4ETS eliminates
this disadvantage. It provides good
steerability by automatically braking the
spinning wheel. As a result, 4ETS directs
more driving power to the wheel standing on
firm ground, which is therefore able to
provide propulsion.
ESP® and 4ETS are traction systems that are
ideal for road driving and suitable for light off-
road driving. Off-road gear LOW likewise
improves off-road capabilities.
Moreover, the more difficult conditions in off-
road driving require further measures such as
locking one or several differentials. Your
vehicle is equipped with three differential
locks:
R a central differential lock for the transfer
case,
R a differential lock for the front axle and
R a differential lock for the rear axle.
Each differential lock can be engaged with the
respective switch on the center console.
When the central differential lock for the
transfer case is locked, the speed of the front
wheels is equal to that of the rear wheels.
When the differential for the rear axle is
locked, both rear wheels turn equally fast, 148
Off-road driving systems
Driving and parking

Problem Possible causes/consequences and
M Solutions$ (USA only)
J (Canada only)
!
The red brake system
warning lamp and the
yellow ABS warning
lamp are on while
driving. In addition, a
warning tone sounds
for about five seconds.
G
Risk of accident
EBD is faulty.
The brake
system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
X Drive on carefully.
X Visit a qualified specialist workshop. ÷
The yellow ESP
®
warning lamp flashes
while the vehicle is in
motion. G
Risk of accident
ESP ®
or traction control is intervening because there is a risk of
skidding or because at least one wheel has started to spin.
X When pulling away, only depress the accelerator pedal as far as
necessary.
X Ease off the accelerator pedal after pulling away.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
For exceptions: (

Y page 55).å
The yellow ESP
®
OFF
warning lamp

is lit while
the engine is running. G
Risk of accident
ESP ®
is deactivated. ESP ®
will not stabilize the vehicle if it starts
to skid or if a wheel starts to spin.
X Reactivate ESP ®
.
For exceptions: (
Y page 55).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Have ESP ®
checked at a qualified specialist workshop. 182
Warning and indicator lamps in the instrument cluster
On-board computer and displays

Notes on regularly inspecting wheels
and tires
G
WARNING
Regularly check the tires for damage.
Damaged tires can cause tire inflation
pressure loss. As a result, you could lose
control of your vehicle.
Worn, old
tires can cause accidents. If the tire
tread is worn to minimum tread depth, or if
the tires have sustained damage, replace
them.
R Regularly check the wheels and tires of
your vehicle for damage (e.g. cuts,
punctures, tears, bulges on tires and
deformation or cracks or severe corrosion
on wheels) at least once a month, as well
as after driving off-road or on rough roads.
Damaged wheels can cause a loss of tire
pressure.
R Regularly check the tire tread depth and
the condition of the tread across the whole
width of the tire (Y page 243). If necessary,
turn the front wheels to full lock in order to
inspect the inner side of the tire surface.
R All wheels must have a valve cap to protect
the valve against dirt and moisture. Do not
install anything onto the valve (such as tire
pressure monitoring systems) other than
the standard valve cap or other valve caps
approved by Mercedes-Benz for your
vehicle.
R You should regularly check the pressure of
all your tires including the spare wheel,
particularly prior to long trips. Adjust the
tire pressure as necessary ( Y page 245).Tire tread
G
WARNING
Although
the applicable federal motor vehicle
safety laws consider a tire to be worn when
the tread wear indicators (TWI) become
visible at approximately 1
/ 16 in (1.6 mm), we
recommend that you do not allow your tires to wear down to that level. As tread depth
approaches
1
/ 8 in (3 mm), the adhesion
properties on

a wet road are sharply reduced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
Do not use tires that are excessively worn as
the tire traction on wet road surfaces
decreases significantly when the tread depth
is less than 1
/ 8 in (3 mm).
Tread wear indicators (TWI) are required by
law. Six indicators are positioned over the tire
tread. They are visible as soon as a tread
depth of approximately 1
/ 16 in (1.6 mm) is
reached. If this is the case, the tire is so worn
that it must be replaced.
The recommended tread depth for summer
tires is at least 1
/ 8 in (3 mm). The
recommended tread depth for winter tires is
at least 1
/ 6 in (4 mm). Indicator
: for tread wear is integrated into
the tire tread. Notes on selecting, mounting and
replacing tires
R Only mount tires and wheels of the same
type and make.
R Only mount tires of the correct size onto
the wheels.
R After mounting new tires, run them in at
moderate speeds for the first 60 miles Operation
243
Wheels and tires Z

i
The actual values for tires are vehicle-
specific and
may deviate from the values in
the illustration.
Maximum tire load : is the maximum
permissible weight for which the tire is
approved.
Further information on tire loads
(Y page 258). Uniform Tire Quality Grading
Standards
Overview of Tire Quality Grading
Standards
The Uniform Tire Quality Grading Standards
are U.S. government specifications. Their
purpose is to provide drivers with uniform
reliable
information

on tire performance data.
Tire manufacturers have to grade tires using
three performance factors: tread wear :,
tire traction ;, and heat resistance =. All
tires sold in North America are provided with
the corresponding quality grading markings on the sidewall of the tire, even though these
regulations do not apply to Canada.
i
The actual values for tires are vehicle-
specific and

may deviate from the values in
the illustration.
Where applicable, the tire grading
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
For example: Tread wear Traction Temperature
200 AA A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Tread wear
The tread

wear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
U.S. government test track. For example, a
tire graded 150 would wear one and one-half
times as well on the government test track as
a tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use,
however, and may depart significantly from
the norm, due to variations in driving habits,
service practices and differences in road
characteristics and climate conditions. Traction
G
WARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent Uniform Tire Quality Grading Standards
257
Wheels and tires Z

the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified
government
test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance. G
WARNING
If ice has formed on the road, tire traction will
be substantially

reduced. Under such weather
conditions, drive, steer and brake with
extreme caution.
The safe speed on a wet, snow covered or icy
road is always lower than on dry road
surfaces.
You should pay special attention to road
conditions when temperatures are around
the freezing point.
Mercedes-Benz recommends a minimum
tread depth of 1
/ 6 in (4 mm) for all four winter
tires ( Y page 244) to maintain normal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow covered
surfaces in comparison to summer tires. The
braking distance is still much further than on
surfaces that are not icy or covered with
snow. Take appropriate care when driving.
! Avoid wheelspin. This can lead to damage
to the drive train. Temperature
G
WARNING
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heat build-up and possible tire
failure.
The temperature grades are A (the highest),
B, and C, These represent the tire's
resistance to the generation of heat and its
ability to dissipate heat when tested under
controlled conditions on a specified indoor laboratory test wheel. Sustained high
temperature
can

cause the material of the tire
to degenerate and reduce tire life, and
excessive temperature can lead to sudden
tire failure. The grade C corresponds to a level
of performance which all passenger car tires
must meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades B and A
represent higher levels of performance on the
laboratory test wheel than the minimum
required by law. Tire labeling
Tire labeling overview
The following markings are on the tire in
addition to the tire name (sales designation)
and the manufacturer's name: :
Uniform tire Quality Grading Standard
(Y page 257)
; DOT, Tire Identification Number
(Y page 261)
= Maximum tire load ( Y page 256)
? Maximum tire pressure (Y page 248)
A Manufacturer
B Tire material ( Y page 262)
C Tire size designation, load-bearing
capacity and speed index (
Y

page 259)258
Tire labeling
Wheels and tires

Maximum tire load
The maximum tire load is the maximum
permissible weight in kilograms or lbs for
which a tire is approved. Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire. Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing
the maximum axle load of one axle
by two. PSI (pounds per square inch)
Standard unit of measurement for tire
pressure. Aspect ratio
Relationship between tire height and tire
width in percent. Tire pressure
This is pressure inside the tire applying an
outward force to every square inch of the
tire's surface.

The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold. For this,
the vehicle must have been stationary for at
least 3 hours or not have traveled more than
1.6 km (1 mile) in this time. Tire tread
The part of the tire that comes into contact
with the road. Tire bead
The tire bead ensures that the tire sits
securely on

the wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim. Sidewall
The part

of the tire between the tread and the
tire bead. Weight of optional extras
The combined

weight of those optional extras
that weigh more than the replaced standard
part and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-
performance battery, are not included in the
curb weight and the weight of the
accessories. TIN (Tire Identification Number)
This is a unique identification number which
can be

used by a tire manufacturer to identify
tires, for example for a product recall, and
thus identify the purchasers. The TIN is made
up of the manufacturer's identity code, tire
size, tire type code and the manufacturing
date. Load bearing index
The load bearing index (also load index) is a
code that

contains the maximum load bearing
capacity of a tire. Traction
Traction is the result of friction between the
tires and the road surface. 264
Definition of terms for tires and loading
Wheels and tires