The vehicle will then use very little energy, thus
conserving battery power.
If the power supply has been interrupted, e.g. ifyou reconnect the battery, you will have to:
Rset the clock; see the Digital Operator's Man-
ual
On vehicles with a multimedia system and
navigation system, the clock is set automati-
cally.
Rreset the function for folding the exterior mir-
rors in/out automatically, by folding the mir-
rors out once (
Ypage 103).
Charging the 12 V battery
GWARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
GWARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases
can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
!Only use battery chargers with a maximum
charging voltage of 14.8 V.
!Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (
Ypage 333).
XOpen the hood.
XConnect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure (
Ypage 333).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the
battery charger's operating instructions before
charging the battery.
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do not
light up, it is highly likely that the discharged
battery has frozen. In this case you may neither
jump-start the vehicle nor charge the battery.
The service life of a thawed-out battery may be
shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have
the thawed-out battery checked at a qualified
specialist workshop.
Jump-starting
PLUG‑IN HYBRID vehicles: it is essential to comply with the separate operating instructions. You
could otherwise fail to recognize dangers e.g. due to high voltage.
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment, consisting of a positive terminal and a ground point.
Jump-starting333
Breakdown assistance
Z
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
GWARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
RMake sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
RNever place metal objects or tools on a battery.
RIt is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
RWhen jump-starting, make sure that the battery poles with identical polarity are connected.
RIt is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
RNever connect or disconnect the battery terminals while the engine is running.
GWARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion. Allow the frozen battery to thaw out before charging it or jump-starting.
!Vehicles with a gasoline engine: avoid repeated and lengthy starting attempts. Otherwise, the
catalytic converter could be damaged by non-combusted fuel.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may neither jump-start the vehicle nor charge the
battery. The service life of a thawed-out battery may be shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have the thawed-out battery checked at a qualified
specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a second battery using jumper cables.
Observe the following points:
RThe battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a second battery or a jump-starting device.
RVehicles with a gasoline engine: only jump-start the vehicle when the engine and exhaust
system are cold.
RDo not start the engine if the battery is frozen. Let the battery thaw first.
ROnly jump-start from batteries with a 12 V voltage rating.
334Jump-starting
Breakdown assistance
Important safety notes
GWARNING
Eac htire, includin gth espar e(if provided),
should be checke dat least once amonth
when cold and inflated to th epressur erec -
ommended by th evehicl emanufacturer on
th eTir eand Loading Information placard on
th edriver' sdoor B-pillar or th etire pressur e
label on th einside of th efuel filler flap .If your
vehicl ehas tires of adifferen tsiz ethan th e
siz eindicated on th eTir eand Loading Infor -
mation placard or th etire pressur elabel, you
should determine th eproper tire pressur efor
those tires .
As an added safet yfeature, your vehicl ehas
been equipped wit h atire pressur emonitoring
system (TPMS) that illuminate s alow tire pres-
sur etelltale when on eor mor eof your tires
are significantly underinflated. Accordingly,
when th elow tire pressur etelltale illuminates,
you should stop and chec kyour tires as soo n
as possible ,and inflat ethem to th eproper
pressure. Drivin gon asignificantly underin-
flated tire causes th etire to overheat and can
lead to tire failure. Underinflation also
reduce sfuel efficiency and tire tread life ,and
may affec tth evehicle's handlin gand stop-
pin gability.
Pleas enote that th eTPM Sis no t asubstitut e
for proper tire maintenance ,a
nd it is th edriv -
er' sresponsibilit yto maintai ncorrec ttire
pressure, eve nif underinflation has no t
reached th elevel to trigge rillumination of th e
TPM Slow tire pressur etelltale.
US Aonly:
Your vehicl ehas also been equipped wit h a
TPM Smalfunction indicator to indicat eif th e
system is no toperating properly. The TPM S
malfunction indicator is combined wit hth e
low tire pressur etelltale. When th esystem
detects amalfunction ,th ewarning lamp will
flas hfor approximately aminute and then
remain continuously illuminated. This
sequenc ewill be repeated every time th evehi-
cle is started as lon gas th emalfunction
exists.
When th emalfunction indicator is illuminated,
th esystem may no tbe able to detec tor signal
low tire pressur eas intended. TPM Smalfunc -
tion smay occur for avariet yof reasons,
includin gth emounting of incompatible
replacemen tor alternate tires or wheels on
th evehicl ethat preven tth eTPM Sfrom func-
tioning properly. Always chec kth eTPM Smal-
function telltale after replacing on eor mor e
tires or wheels on your vehicl eto ensur ethat
th ereplacemen tor alternate tires and wheels
allow th eTPM Sto continue to function prop-
erly.
It is th edriver' sresponsibilit yto set th etire
pressur eto that recommended for cold tires
whic his suitable for th eoperating situation
(
Ypage 344). Not ethat th ecorrec ttire pressur e
for th ecurren toperating situation must first be
taught-in to th etire pressur emonitor. If there is
a substantial loss of pressure, th ewarning
threshold for th ewarning message is aligned to
th ereferenc evalue staught-in .Restart th etire
pressur emonitor after adjusting th epressur eof
th ecold tires (
Ypage 350). The curren tpres-
sures are saved as ne wreferenc evalues. As a
result , awarning message will appear if th etire
pressur e
d
rops significantly.
The tire pressur emonitor does no twarn you of
an incorrectl yset tire pressure. Observ eth e
note son th erecommended tire pressur e
(
Ypage 344).
The tire pressur emonitor is no table to warn you
of asudde nloss of pressure, e.g. if th etire is
penetrated by aforeign object. In th eevent of a
sudde nloss of pressure, brin gth evehicl eto a
halt by braking carefully. Avoid abrup tsteering
movements.
The tire pressur emonitor has ayellow warning
lamp in th einstrumen tcluste rfor indicating
pressur eloss or amalfunction .Whether th e
warning lamp flashes or lights up indicates
whether atire pressur eis to olow or th etire
pressur emonitor is malfunctioning :
Rif thewarning lamp is lit continuously, th etire
pressur eon on eor mor etires is significantly
to olow. The tire pressur emonitor is no tmal-
functioning .
Rif thewarning lamp flashes for aroun d a
minute and then remain slit constantly, th e
tire pressur emonitor is malfunctioning .
Tire pressure349
Wheels and tires
Z
In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
(
Ypage 262).
It may take up to ten minutes for a malfunction of the tire pressure monitor to be indicated. A
malfunction will be indicated by the tire pres-
sure warning lamp flashing for approximately
one minute and then remaining lit. When the
malfunction has been rectified, 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.
Checking the tire pressure electroni-
cally
XMake sure that the SmartKey is in position 2
in the ignition lock (Ypage 132).
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 longer than
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.
If an emergency spare wheel is mounted, the
system may continue to show the tire pressure of the wheel that has been removed for a few
minutes. If this occurs, note that the value dis-
played for the position where the spare wheel is
mounted 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 pressure
loss in one or more tires, a warning message is
shown in the multifunction display. The yellow
tire pressure warning lamp then lights up.
RIf the
Please Correct Tire Pressuremessage appears in the multifunction display,
the tire pressure in at least one tire is too low.
The tire pressure must be corrected when the
opportunity arises.
RIf theCheck Tiresmessage appears in the
multifunction display, the tire pressure in at
least one tire has dropped significantly. The
tires must be checked.
RIf the WarningTireMalfunctionmessage
appears in the multifunction display, the tire
pressure in at least one tire has dropped sud- denly. The tires must be checked.
Be sure to observe the instructions and safety
notes in the display messages in the "Tires" sec-
tion (
Ypage 262).
If 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 pres-
sures are displayed for the correct 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. The tire
pressure monitor then monitors the new tire
pressure values.
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 344).
350Tire pressure
Wheels and tires
Tire labeling
Overview
:Uniform Tire Quality Grading Standards
(Ypage 359)
;Department of Transportation, Tire Identifi-
cation Number (Ypage 358)
=Maximum load rating (Ypage 358)
?Maximum tire pressures (Ypage 347)
AManufacturer
BTire material (Ypage 359)
CTire size designation, load-bearing capacity
and speed rating (Ypage 356)
DLoad index (Ypage 358)
ETire name
The markings described above are on the tire in
addition to the tire name (sales designation) and
the manufacturer's name.
iTire data is vehicle-specific and may deviate
from the data in the example.
Tire size designation, load-bearing
capacity and speed rating
GWARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed could
lead to tire damage or the tire bursting. There is a risk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle.
:Tire width
;Nominal aspect ratio in %
=Tire code
?Rim diameter
ALoad bearing index
BSpeed rating
General: depending on the manufacturer's
standards, the size imprinted in the tire wall may
not contain any letters or may contain one letter
that precedes the size description.
If there is no letter preceding the size descrip-
tion (as shown above): these are passenger
vehicle tires according to European manufac-
turing standards.
If "P" precedes the size description: these are
passenger vehicle tires according to U.S. man-
ufacturing standards.
If "LT" precedes the size description: these are
light truck tires according to U.S. manufacturing
standards.
If "T" precedes the size description: compact
emergency wheels with high tire pressure that
are only designed for temporary use in an emer-
gency.
Tire width: tire width:shows the nominal tire
width in millimeters.
Height-width ratio: aspect ratio;is the size
ratio between the tire height and tire width and
is shown in percent. The aspect ratio is calcula-
ted by dividing the tire width by the tire height.
Tire code:tire code =specifies the tire type.
"R" represents radial tires; "D" represents diag-
onal tires
; "B" represents diagonal radial tires.
Optionally, tires with a maximum speed of over
149 mph (240 km/h) may have "ZR" in the size
356All about wheels an d tires
Wheels and tires