!A function or performance test should only
be carried out on a two-axle dynamometer.
Before you operate the vehicle on such a
dynamometer, please consult a qualified
workshop. You could otherwise damage the
drive train or the brake system.
The all-wheel drive system ensures that all four
wheels are permanently driven. The all-wheel
drive system improves vehicle traction together
with ESP
®and 4ETS if a drive wheel spins due to
insufficient grip.
If a drive wheel spins due to insufficient grip:
ROnly depress the accelerator pedal as far as
necessary when pulling away.
RTake your foot off the accelerator, slowly,
while the vehicle is in motion.
The permanent all-wheel drive system can nei-
ther reduce the risk of accident nor override the
laws of physics if you fail to adapt your driving
style or if you are inattentive. The all-wheel drive
system cannot take into account road, weather
or traffic conditions. The all-wheel drive system
is only an aid. You are responsible for maintain-
ing a safe distance to the vehicle in front, for
vehicle speed, for braking in good time and for
staying in lane.
In wintry driving conditions, always use winter
tires (M+S tires) and if necessary, snow chains
(
Ypage 264). Only in this way can the maximum
effect of all-wheel drive be achieved.
For information on driving off-road, see
(
Ypage 137).
PARKTRONIC
Important safety notes
!When parking, pay particular attention to
objects above or below the sensors, such as
flower pots or trailer drawbars. PARKTRONIC
does not detect such objects when they are in the immediate vicinity of the vehicle. You
could damage the vehicle or the objects.
The sensors may not detect snow and other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic car
wash, the compressed-air brakes on a truck
or a pneumatic drill could cause PARKTRONIC
to malfunction.
PARKTRONIC may not function correctly on
uneven terrain. PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and audi-
bly the distance between your vehicle and an
object.
PARKTRONIC is only an aid. It is not a replace-
ment for your attention to your immediate sur-
roundings. You are always responsible for safe
maneuvering, parking and exiting a parking
space. Ensure that the areas in front, behind and
to the side of the vehicle are safe before maneu-
vering, parking or pulling away. There must not
be any persons, animals or objects in the area in
which you are maneuvering.
PARKTRONIC does not take into account any
persons or objects located below or above the
detection range. As a result, PARKTRONIC can-
not warn you about objects in this area.
PARKTRONIC is activated automatically when
you:
Rswitch on the ignition
Rshift the transmission to position D,Ror N
Rrelease the parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper.
Range of the sensors
General notes
:Example: sensors in the front bumper, right-
hand side
158Driving systems
Driving and parking
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate if the
system is not operating properly. The TPMS
malfunction indicator is combined with the
low tire pressure telltale. When the system
detects a malfunction, the warning lamp will
flash for approximately a minute and then
remain continuously illuminated. This
sequence will be repeated every time the vehi-
cle is started as long as the malfunction
exists.
When the malfunction indicator is illuminated,
the system may not be able to detect or signal
low tire pressure as intended. TPMS malfunc-
tions may occur for a variety of reasons,
including the mounting of incompatible
replacement or alternate tires or wheels on
the vehicle that prevent the TPMS from func-
tioning properly. Always check the TPMS mal-
function telltale 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 prop-
erly.
It is the driver's responsibility to set the tire
pressure to the recommended cold tire pressure
suitable for the operating situation
(
Ypage 265). Note that the correct tire pressure
for the current operating situation must first be
taught-in to the tire pressure monitor. If there is
a substantial loss of pressure, the warning
threshold for the warning message is aligned to
the reference values taught-in. Restart the tire
pressure monitor after adjusting to the cold tire
pressure (
Ypage 270). The current pressures
are saved as new reference values. As a result, a
warning message will appear if the tire pressure
drops sign ificant
ly.
The tire pressure monitor does not warn you of
an incorrectly set tire pressure. Observe the
notes on the recommended tire pressure
(
Ypage 265).
The tire pressure monitor is not able to warn you
of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid sudden steering
movements.
In order to check the tire pressure, the vehicle's
wheels are installed with sensors that monitor the tire pressure in all four tires. The tire pres-
sure monitor warns you if the pressure drops in
one or more of the tires. The tire pressure mon-
itor only functions if the correct sensors are
installed on all wheels.
The tire pressure monitor has a yellow warning
lamp in the instrument cluster for indicating
pressure loss/malfunctions (USA) or pressure
loss (Canada). Whether the warning lamp
flashes or lights up indicates whether a tire
pressure is too low or the tire pressure monitor is malfunctioning:
Rif the warning lamp is lit continuously, the tire
pressure on one or more tires is significantly
too low. The tire pressure monitor is not mal-
functioning.
RUSA only: if the warning lamp flashes for
around a minute and then remains lit con-
stantly, the tire pressure monitor is malfunc-
tioning.
Information on tire pressures is displayed in the
multifunction display. After a few minutes of
driving, the current tire pressure of each tire is
shown in the multifunction display.
USA only: the tire pressure warning lamp will
inform you of a malfunc
tion in the tire pressure
monitor by flashing for approximately one
minute and then remaining lit. It may take more
than ten minutes before the data menu is dis-
played. When the malfunction has been recti-
fied, the tire pressure warning lamp goes out
after a few minutes of driving.
The tire pressure values indicated by the on-
board computer may differ from those meas-
ured at a gas station with a pressure gauge. The
tire pressures shown by the on-board computer
refer to those measured at sea level. At high
altitudes, the tire pressure values indicated by a
pressure gauge are higher than those shown by the on-board computer. In this case, do not
reduce the tire pressures.
The operation of the tire pressure monitor can
be affected by interference from radio transmit-
ting equipment (e.g. radio headphones, two-way
radios) that may be being operated in or near the
vehicle.
iUSA only:
This device complies with part 15 of the FCC
Rules. Operation is subject to the following
two conditions:
1. This device may not cause harmful inter-
ference, and
Tire pressure269
Wheels and tires
Z
2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
iCanada only:
This device complies with RSS-210 of Indus-
try Canada. Operation is subject to the fol-
lowing two conditions:
1. This device may not cause harmful inter-
ference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
Checking the tire pressure electroni-
cally
XMake sure that the SmartKey is in position 2
in the ignition lock (Ypage 112).
XPress the =or; button on the steering
wheel to select the Serv.menu.
XPress the9or: button to select
Tire Pressure.
XPress the abutton.
The current tire pressure of each tire is shown
in the multifunction display.
If the vehicle has been parked for over
20 minutes, the Tire pressure will be
displayed after driving a few minutesmessage appears.
After a teach-in process, the tire pressure mon-
itor automatically detects new wheels or new
sensors. As long as a clear allocation of the tire
pressure value to the individual wheels is not
possible, theTire
PressureMonitorActivedisplay message is shown instead of the tire
pressure display. The tire pressures are already
being monitored.
iIf a spare wheel is mounted, the system may
continue to show the tire pressure of the
wheel that has been removed for a few
minutes. Observe that the displayed value is
not the same as the current tire pressure of
the emergency spare wheel.
Tire pressure monitor warning mes-
sages
If the tire pressure monitor detects a significant
pressure loss on one or more tires, a warning
message is shown in the multifunction display. A
warning tone also sounds and the tire pressure
warning lamp lights up in the instrument cluster.
Each tire that is affected by a significant loss of
pressure is highlighted in the pressure display.
XIf the Correct Tire Pressuremessage
appears in the multifunction display, check
the tire pressure on all four wheels and cor-
rect it if necessary.
XIf the Check Tiresmessage appears in the
multifunction display, the tire pressure in one
or more tires has dropped significantly and
the tires must be checked.
XIf the Tire Press. Warning CautionTire Malfunctionmessage appears in the
multifunction display, the tire pressure in one
or more tires has dropped suddenly and the
tires must be checked.
iIf the wheel positions on the vehicle are
rotated, the tire pressures may be displayed
for the wrong positions for a short time. This is
rectified after a few minutes of driving, and
the tire pressures are displayed for the cor-
rect positions.
Restarting the tire pressure monitor
When you restart the tire pressure monitor, all
existing warning messages are deleted and the
warning lamps go out. The monitor uses the cur-
rently set tire pressures as the reference values for monitoring. In most cases, the tire pressure
monitor will automatically detect the new refer-
ence values after you have changed the tire
pressure. However, you can also define refer-
ence values manually as described here.
XSet the tire pressure to the value recommen- ded for the corresponding driving situation on
the Tire and Loading Information placard on
the driver's side B-pillar (
Ypage 265).
Additional tire pressure values for different
loads can also be found on the tire pressure
table on the inside of the fuel filler flap
(
Ypage 265).
XMake sure that the tire pressure is correct on
all four wheels.
270Tire pressure
Wheels and tires
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 cli-
mate conditions.
Traction
GWARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor-
nering, hydroplaning, or peak traction char-
acteristics.
!Avoid wheelspin. This can lead to damage to
the drive train.
The traction grades, from highest to lowest, are
AA, A, B, and C. Those grades represent the
tire's ability to stop on a wet surface as meas-
ured under controlled conditions on specified
government test surfaces of asphalt and con-
crete. A tire marked C may have poor traction
performance.
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 condi-
tions when temperatures are around freezing
point.
Mercedes-Benz recommends a minimum tread
depth of ãin (4 mm) on all four winter tires.
Observe the legally required minimum tire tread
depth (
Ypage 263). Winter tires can reduce the
braking distance on snow-covered surfaces in
comparison with summer tires. The braking dis-
tance is still much further than on surfaces that
are not icy or covered with snow. Take appro-
priate care when driving.
Further information on winter tires (M+S tires)
(
Ypage 264).
Temperature
GWARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, 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. Sus-
tained 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
Overview of tire labeling
:Uniform tire Quality Grading Standard
(Ypage 279)
;DOT tire Identification Number
(Ypage 278)
=Maximum tire load (Ypage 278)
?Maximum tire pressures (Ypage 268)
AManufacturer
BTire material (Ypage 279)
CTire size designation, load-bearing capacity
and speed rating (Ypage 276)
Tire labeling275
Wheels and tires
Z
identify speed ratingBon the sidewall of the
tire (Ypage 276).
RIf no specification is given: no text (as in the
example above), represents a standard load
(SL) tire
RXL or Extra Load: represents a reinforced tire
RLight Load: represents a light load tire
RC, D, E: represents a load range that depends
on the maximum load that the tire can carry at
a certain pressure
iTire data is vehicle-specific and may deviate
from the data in the example.
Maximum load rating
Maximum tire load :is the maximum permis-
sible weight for which the tire is approved.
Do not overload the tires by exceeding the
specified load limit. The maximum permissible
load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on
the driver's side (
Ypage 271).
iThe actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
DOT, Tire Identification Number (TIN)
U.S. tire regulations prescribe that every man-
ufacturer of new tires or retreader has to imprint
a TIN in or on the sidewall of each tire produced.
The TIN is a unique identification number. The
TIN enables tire manufacturers to inform pur-
chasers of recalls and other safety-relevant mat-
ters. It makes it possible for the purchaser to
easily identify the affected tires.
The TIN is made up of manufacturer identifica-
tion code ;, tire size =, tire type code ?and
manufacturing date A.
DOT (Department of Transportation): tire
symbol :indicates that the tire complies with
the requirements of the U.S. Department of
Transportation.
Manufacturer identification code: manufac-
turer identification code ;provides details on
the tire manufacturer. New tires have a code
with two symbols. Retreaded tires have a code
with four symbols.
For further information about retreaded tires,
see (
Ypage 262).
Tire size: identifier=describes the tire size.
Tire type code: tire type code?can be used by
the manufacturer as a code to describe specific
characteristics of the tire.
Date of manufacture: date of manufactureA
provides information about the age of a tire. The
first and second positions represent the week of
manufacture, starting with "01" for the first cal-
endar week. Positions three and four represent
the year of manufacture. For example, a tire that
is marked with "3208", was manufactured in
week 32 in 2008.
iTire data is vehicle-specific and may deviate
from the data in the example.
278Tire labeling
Wheels and tires