318 Operation
Tires and wheels
Warning!G
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended by the vehicle manufacturer on the
Tire and Loading Information placard or, if
available, on the tire inflation pressure label.
If your vehicle has tires of a different size
than the size indicated on the Tire and
Loading Information placard or, if available,
the tire inflation pressure label, you should
determine the proper tire inflation pressure
for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly underinflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a significant-
ly underinflated tire causes the tire to over-
heat and can lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the TPMS is not a substitute for
proper tire maintenance, and it is the driv-
er’s responsibility to maintain correct tire
pressure, even if underinflation has not
reached the level to trigger illumination of
the TPMS low tire pressure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate
when the system is not operating properly.
The TPMS malfunction indicator is com-
bined with the low tire pressure telltale.
When the system detects a malfunction, the
telltale will flash for approximately 1 minute
and then remain continuously illuminated.
This sequence will continue upon subse-
quent vehicle start-ups as long as the mal-
function exists. When the malfunction
indicator is illuminated, the system may not
be able to detect or signal low tire pressure
as intended.TPMS malfunctions may occur for a variety
of reasons, including the installation of
replacement or alternate tires or wheels on
the vehicle that prevent the TPMS from
functioning properly. Always check the
TPMS malfunction 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 properly.
iIf a condition causing the TPMS to malfunc-
tion develops, it may take up to 10 minutes
for the system to signal a malfunction using
the TPMS telltale flashing and illumination
sequence.
The telltale extinguishes after a few minutes
driving if the malfunction has been corrected.
iOperating radio transmission equipment
(e.g. wireless headsets, two-way radios) in or
near the vehicle could cause the TPMS to mal-
function.
331 Operation
Tires and wheels
Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power
seats, radio, and heater, to the extent that
these items are available as
factory-installed equipment (whether
installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire.
Air pressure is expressed in pounds per
square inch (psi), or kilopascal (kPa), or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.Bar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi)
to 1 bar; there are 100 kilopascals (kPa)
to 1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least three hours or
driven no more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.DOT (Department of Transportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross Axle Weight Rating)
The GAWR is the maximum permissible
axle weight. The gross vehicle weight on
each axle must never exceed the GAWR for
the front and rear axle indicated on the
certification label located on the driver’s
door B-pillar.
GVW (G
ross Vehicle Weight)
The GVW comprises the weight of the
vehicle including fuel, tools, spare wheel,
installed accessories, passengers and
cargo and, if applicable, trailer tongue
load. The GWV must never exceed the
GWVR indicated on the certification label
located on the driver’s door B-pillar.
348 Practical hints
What to do if …
Lamps in instrument clusterGeneral information:
If any of the following lamps in the instru-
ment cluster fails to come on during thebulb self-check when switching on ignition
(
page 37), have the respective bulb
checked and replaced if necessary.
ProblemPossible cause/consequenceSuggested solution
-The yellow ABS indicator lamp comes on
when the engine is running.The ABS has detected a malfunction
and has switched off. The BAS and
ESP
® are also switched off (see mes-
sages in the multifunction display).
The brake system is still functioning
normally but without the systems
specified above.
If the ABS control unit is malfunction-
ing, other systems such as the naviga-
tion system* or the automatic
transmission* may also be malfunc-
tioning.
Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.
Read and observe messages in the
multifunction display (
page 360).
Have the system checked at an
authorized Mercedes-Benz Center as
soon as possible.
Failure to follow these instructions in-
creases the risk of an accident.
The charging voltage has fallen below
10 volts. The ABS has switched off.
The battery might not be charged suf-
ficiently.When the voltage is above this value
again, the ABS is operational again an the
ABS indicator lamp should go out.
If the ABS indicator lamp does not go out:
Have the generator (alternator) and
battery checked.
364 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
SRSRestraint System Malfunction
Service RequiredThere is a malfunction in the supple-
mental restraint systems. The air bags
or emergency tensioning devices
(ETDs) could deploy unexpectedly or
fail to activate in an accident.Drive with added caution to an
authorized Mercedes-Benz Center
and have the system checked
immediately.
TransmissionService RequiredVehicles with automatic transmis-
sion*:
The provided operating safety of the
automatic transmission is reduced.Drive with added caution to the
nearest authorized Mercedes-Benz
Center.
Warning!G
In the event a malfunction of the SRS is
indicated as outlined above, the SRS may
not be operational. For your safety, we
strongly recommend that you contact an
authorized Mercedes-Benz Center immedi-
ately to have the system checked; otherwise
the SRS may not be deployed when needed
in an accident, which could result in serious
or fatal injury, or it might deploy
unexpectedly and unnecessarily which
could also result in an accident and/or
injury to you or to others.
396 Practical hints
Unlocking/locking in an emergency
Insert mechanical key 2 into the
driver’s door lock until it stops.
Turn mechanical key 2 clockwise to
position1.
The driver’s door is locked.
Turn back mechanical key 2 and
remove it from driver’s door lock.Manually unlocking the gear selector
lever (automatic transmission*)
In case of power failure, the gear selector
lever can be manually unlocked, e.g. to tow
the vehicle.
1Gear selector lever cover
2Release
Insert flat, blunt object (e.g. screw-
driver) into the left edge of cover1 at
the position indicated by the arrows.
Loosen cover1 using this object.
Using your hands, pull cover1 out
and remove.
Push down and hold release2 in
direction of arrow.
Simultaneously move gear selector
lever out of positionP.
The gear selector lever is unlocked
now.1Locking
2Mechanical key
iThis procedure does not arm the anti-theft
alarm system, nor does it lock the fuel filler flap
and the storage compartments.
iThe gear selector lever is locked again as
soon as you place it in positionP again.
408 Practical hints
Flat tire
The SLK 55 AMG with Performance
Package* is equipped with a TIREFIT kit.
Preparing the vehicle
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flashers.
Turn the steering wheel so that the
front wheels are in a straight ahead
position.
Set the parking brake (page 53).
Move the gear selector lever* toP
(manual transmission to first or reverse
gear).
Turn off the engine (page 61).
Remove the SmartKey from the starter
switch.
Have any passenger exit the vehicle at
a safe distance from the roadway.
Sealing tires with TIREFIT
Small tire punctures, particularly those in
the tread, can be sealed with TIREFIT.
TIREFIT can be used in ambient tempera-
tures down to -4°F (-20°C).Foreign objects (e.g. screws or nails)
should not be removed from the tire.
Take TIREFIT, the sticker, and the
electric air pump out of the trunk
(
page 389).
Two-part sticker
1Sticker for instrument cluster
2Sticker for wheel
Attach sticker part 1 where it will be
easily seen by the driver on the instru-
ment cluster.
Attach sticker part 2 to the damaged
tire (close to the tire valve).iOpen door only when conditions are safe to
do so.
iSLK 55 AMG with Performance Package*
only.
Warning!G
TIREFIT is a limited repair device. TIREFIT
cannot be used for cuts or punctures larger
than approximately 0.16 in (4 mm) and tire
damage caused by driving with extremely
low tire inflation pressure, or on a flat tire, or
a damaged wheel.
Do not drive the vehicle under such circum-
stances.
Contact the nearest Mercedes-Benz Center
for assistance or call Roadside Assistance.
423 Practical hints
Battery
Disconnecting the battery
1Water tray
2Lock
Apply the parking brake (page 59).
Make sure the gear selector lever* is
set to positionP (manual transmission
to Neutral).
Turn off all electrical consumers.
Remove the SmartKey from the starter
switch.
Open the hood (page 294).
Turn locks2 one quarter turn.
Remove water tray1.
Read and observe safety instructions
and precautions (
page 302) and
(
page 422).
Use a 10 mm open-end wrench to dis-
connect the negative lead from battery
negative terminal3 (
page 422).
Remove the cover from battery positive
terminal 2 (
page 422).
Use a 10 mm open-end wrench to dis-
connect the positive lead from battery
positive terminal2 (
page 422).
Warning!G
With a disconnected battery
you will no longer be able to turn the
SmartKey in the starter switch
automatic transmission*: the gear se-
lector lever will remain locked in
positionP
!Always disconnect the battery in the order
described below. Otherwise the vehicle’s
electronics can be damaged.
426 Practical hints
Jump starting
If the battery is discharged, the engine can
be started with jumper cables and the bat-
tery of another vehicle. Observe the follow-
ing:
Jump starting should only be performed
when the engine and catalytic convert-
er are cold.
Do not start the engine if the battery is
frozen. Let the battery thaw out first.
Only jump start from batteries with the
same voltage rating (12 V). Jump start-
ing with a higher voltage battery could
damage the vehicle’s electrical system,
which will not be covered by the
Mercedes-Benz Limited Warranty.
Only use jumper cables with sufficient
cross-section and insulated terminal
clamps.
Always make sure the jumper cables
are not on or near pulleys, fans, or
other parts that move when an engine
is started or running.
Warning!G
Failure to follow these directions will cause
damage to the electronic components, and
can lead to a battery explosion and severe
injury or death.
Never lean over batteries while connecting
or jump starting, as you could otherwise be
injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water, and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and very explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
Attempting to jump start a frozen battery
can result in it exploding, causing personal
injury.
Read all instructions before proceeding.
!Vehicles with automatic transmission*:
Do not tow-start vehicle.
!Avoid repeated and lengthy starting
attempts.
Do not attempt to start the engine using a
battery quick charge unit.
If the engine does not run after several
unsuccessful starting attempts, have it checked
at the nearest authorized Mercedes-Benz
Center.
Excessive unburned fuel generated by repeated
failed starting attempts may damage the
catalytic converter and may present a fire risk.
Make sure the jumper cables do not have loose
or missing insulation.
Make sure the cable clamps do not touch any
other metal part while the other end is still at-
tached to a battery.