Page 399 of 474

398 Practical hints
Replacing SmartKey batteries
If the batteries in the SmartKey are
discharged, the vehicle can no longer be
locked or unlocked. It is recommended
to have the batteries replaced at an autho-
rized Mercedes-Benz Center.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key from the
SmartKey (
page 394).1Mechanical key
2Battery compartment
Insert mechanical key1 into opening.
Press mechanical key1 in direction of
arrow.
Battery compartment2 is unlatched.
Pull battery compartment2 out of the
housing.
Warning!G
Batteries contain poisonous and corrosive
substances. Therefore keep the batteries
out of reach of children.
If a battery is swallowed, seek medical help
immediately.
Warning!G
SmartKey batteries contain Perchlorate
material, which may require special handling
and regard for the environment. Check with
your local government’s disposal guidelines.
California residents, see
http://www.dtsc.ca.gov/HazardousWaste
/Perchlorate/index.cfm.
iWhen inserting the batteries, make sure
they are clean and free of lint.
iWhen replacing batteries, always replace
both batteries.
The required replacement batteries are available
at any Mercedes-Benz Center.
Page 400 of 474
399 Practical hints
Replacing SmartKey batteries
3Batteries
4Contact springs
Pull out batteries 3.
Using a lint-free cloth, insert new
batteries3 under contact springs4
with the positive terminal (+) side
facing up.
Return battery compartment2
(
page 398) into the housing until it
locks into place.
Slide the mechanical key back into the
SmartKey.
Check the operation of the SmartKey.
Page 407 of 474

406 Practical hints
Replacing wiper blades
Placing wiper arms in vertical position
1Wiper arms
Turn the SmartKey in the starter switch
to position1 (
page 37).
Turn combination switch to wiper
settingII (
page 56).
With wiper arms 1 in vertical position,
turn the SmartKey in the starter switch
to position0.
Remover the SmartKey from the starter
switch.
Warning!G
For safety reasons, switch off wipers and
remove the SmartKey from the starter
switch before replacing a wiper blade.
Otherwise, the motor could suddenly turn
on and cause injury.
Warning!G
Wiper blades are components that are
subject to wear and tear. Replace the wiper
blades twice a year, preferably in the spring
and fall. Otherwise the windows will not be
properly wiped. As a result, you may not
be able to observe surrounding traffic condi-
tions and could cause an accident.
!To avoid damage to the hood:
The wiper arms should only be folded for-
ward when in the vertical position.
Never open the hood when a wiper arm is
folded forward.
!Hold on to the wiper when folding the wiper
arm back. If released, the force of the impact
from the tensioning spring could crack the wind-
shield.
Do not allow the wiper arms to contact the wind-
shield glass without a wiper blade inserted.
For your convenience, we recommend that you
have this work carried out by an authorized
Mercedes-Benz Center.
Page 409 of 474

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.
Page 412 of 474

411 Practical hints
Flat tire
Version 1
aVent screw
bPressure gauge
Close vent screwa on pressure
gaugeb (version 1 only).
Screw filler hose8 onto tire valve9
(
page 410).
Insert electrical plug4 (page 410)
into the cigarette lighter (
page 256).
Turn the SmartKey in the starter switch
to position1 (
page 37).
PressI on electric air pump switch3
(
page 410).
The electric air pump is switched on
and inflates the tire.
Let the electric air pump inflate the tire
for approximately 5 minutes.
The pressure gauge must display at
least 26 psi (1.8 bar). The air hose can
become hot during inflation.
Please exercise appropriate caution.
If the tire inflation pressure of at least
26 psi (1.8 bar) is not attained, turn off
the electric air pump by pressing0 on
electric air pump switch3
(
page 410).
Detach filler hose8 f r o m t i r e v a l v e9
(
page 410).
Drive vehicle back and forth very slowly
approximately 30 ft (10 m).
This serves to better distribute the
TIREFIT sealant material inside the tire.
Unscrew the air pump’s air hose5
from flange6 of TIREFIT container1
(
page 410).
Screw air hose5onto tire valve9.
Inflate the tire again.
iFirst, the sealing is pumped into the tire. The
pressure may briefly rise to up to 73 psi (5 bar).
This is normal and not an indication of a malfunc-
tion. Do not switch off the electric air pump.
!Do not operate the electric air pump longer
than 6 minutes without interruption. Otherwise it
may overheat.
You may operate the air pump again after it has
cooled off.
Page 413 of 474

412 Practical hints
Flat tire
After attaining a tire inflation pressure
of 26 psi (1.8 bar), press0 on electric
air pump switch3 (
page 410).
The electric air pump is switched off.
Turn the SmartKey in the starter switch
to position0 (
page 37).
Detach the electric air pump.
The air hose may still be hot. Please
exercise appropriate caution.
Place the electrical air pump back in
the trunk.
Close the trunk lid.
Drive off immediately.
The TIREFIT sealant will distribute itself
evenly inside the tire.
After driving the vehicle for an initial
10 minutes, check the tire inflation
pressure using pressure gauge b on
the air pump.
Warning!G
If a tire inflation pressure of 26 psi (1.8 bar)
is not attained, the tire is too severely
damaged for TIREFIT to provide a reliable
tire repair.
In this case, TIREFIT cannot properly seal
the tire.
Do not drive the vehicle.
Contact the nearest Mercedes-Benz Center
or call Roadside Assistance.
Warning!G
Do not exceed vehicle speed of
50 mph (80 km/h). A TIREFIT repair is not
designed to operate at higher speeds.
The sticker must be attached on the instru-
ment cluster where it will be easily seen by
the driver.
Vehicle handling characteristics of a TIREFIT
repaired tire may change. Adapt your driving
accordingly.
Warning!G
If tire inflation pressure has fallen below
20 psi (1.3 bar) do not continue to drive the
vehicle.
Park your vehicle safely away from the road-
way and contact the nearest authorized
Mercedes-Benz Center or Roadside
Assistance.
Have the damaged tire replaced.
Page 419 of 474

418 Practical hints
Flat tire
Unscrew the alignment bolt, install last
wheel bolt and tighten slightly.
Inflate the collapsible tire
(
page 418).Inflating the collapsible tire
1Flap
2Air pump switch
3Electrical plug
4Air hose with pressure gauge and vent
screw
5Union nut
Take the electric air pump out of the
trunk (
page 390).
Open flap1 on air pump.
Pull out electrical plug3 and air hose
with pressure gauge4.
Close vent screw on air hose4.
Remove the valve cap from the tire
valve.
Screw union nut5 onto the tire valve.
Make sure electric air pump switch2
is set to0.
Insert electrical plug3 into the power
outlet in the passenger footwell
(
page 257).
Turn the SmartKey in the starter switch
to position1.
Warning!G
Use only genuine Mercedes-Benz wheel
bolts. Other wheel bolts may come loose.
Do not tighten the wheel bolts when the
vehicle is raised. Otherwise the vehicle
could fall off the jack.Warning!G
Observe instructions on air pump label.
!Do not lower the vehicle before inflating the
collapsible tire. Otherwise the rim may be
damaged.
!The cigarette lighter (page 256) is not de-
signed for use with the electric air pump. Use the
power outlet in the passenger footwell
(
page 257) for electric air pump operation.
Page 420 of 474

419 Practical hints
Flat tire
PressI on electric air pump switch2.
The electric air pump switches on and
inflates the collapsible tire.
Inflate the collapsible tire to approxi-
mately 51 psi (3.5 bar).
This takes about 5 minutes. Air
hose4 and union nut5 can become
hot during inflation. Exercise proper
caution to avoid burning yourself when
using the equipment.
Press0 on electric air pump switch2.
Turn the SmartKey in the starter switch
to position0.
The electric air pump is switched off.
If the tire inflation pressure is above
51 psi (3.5 bar), release excess tire
inflation pressure using the vent screw
on air hose4.
Detach the electric air pump.
Reinstall tire valve cap.
Store electrical plug3 and air
hose4 behind flap 1 and place the
electric air pump back in the trunk.
Lower the vehicle (page 420).
!Compare the recommended tire inflation
pressure for your vehicle with the tire inflation
pressure on the yellow label located on the spare
wheel rim.
If the tire inflation pressure on the yellow label
on the spare wheel rim differs from the values
given in this Operator’s Manual, inflate the
collapsible tire to the recommended tire inflation
pressure given on the yellow label on the spare
wheel rim.
!Do not operate the electric air pump longer
than 6 minutes without interruption. Otherwise it
may overheat.
You may operate the electric air pump again
after it has cooled off.Warning!G
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.