Page 409 of 480

408 Practical hintsFlat tire
Unscrew the alignment bolt, install last
wheel bolt and tighten slightly.Inflating the spare tire
Take the electric air pump out of the
trunk (
page 383).
1Flap
2Air pump switch
3Electrical plug
4Air hose with pressure gauge and vent
screw
5Union nut
Open flap 1 on air pump.
Pull out electrical plug 3 and air hose
with the pressure gauge 4.
Remove the valve cap from the tire
valve.
Screw union nut 5 onto the tire valve.
Insert electrical plug 3 into vehicle ci-
gar lighter socket.
Damaged wheel hub threads should be re-
paired immediately. Do not continue to drive
under these circumstances! Contact an au-
thorized Mercedes-Benz Center or call
Roadside Assistance.
Incorrect wheel bolts or improperly tight-
ened wheel bolts can cause the wheel to
come off. This could cause an accident. Be
sure to use the correct wheel bolts.Warning!
G
Only use genuine equipment
Mercedes-Benz wheel bolts. They are identi-
fied by the Mercedes star. Other wheel bolts
may come loose.
Do not tighten the wheel bolts when the ve-
hicle is raised. Otherwise the vehicle could
fall off the jack.
!Do not lower the vehicle before inflat-
ing the spare wheel tire. Otherwise the
rim may be damaged.Warning!
G
Observe instructions on air pump label.
Page 410 of 480

409 Practical hints
Flat tire
Turn the SmartKey in the starter switch
to position1.
or
Press the KEYLESS-GO* start/stop
button on the gear selector lever once
without depressing the brake pedal.
PressI on the electric air pump
switch2.
The electric air pump should now
switch on and inflate the tire.
Inflate the spare tire for the SL 500 to
36 psi (2.5 bar) and the spare tire for
the SL 600 and SL 55 AMG to 44 psi
(3.0 bar).
This takes about 5 minutes for the
spare tire. Air hose 4 and union
nut5 can become hot during infla-
tion. Exercise proper caution to avoid
burning yourself when using the equip-
ment.
Press0 on the electric air pump
switch2.
Turn the SmartKey in the starter switch
to position0.
or
Press KEYLESS-GO* start/stop button
on the gear selector lever twice without
depressing the brake pedal.
The electric air pump should now be
switched off.
If the spare tire inflation pressure for
the SL 500 is above 36 psi (2.5 bar)
and for the SL 600 and SL 55 AMG
above 44 psi (3.0 bar), release excess
spare tire inflation pressure using the
vent screw.
!Compare the recommended tire infla-
tion pressure for your vehicle with the
tire inflation pressure on the yellow la-
bel located on the spare wheel rim.
If the tire inflation pressure on the yel-
low label on the spare wheel rim differs
from the values given in this Operator’s
Manual, inflate the tire to the recom-
mended tire inflation pressure given on
the yellow label on the spare wheel rim.!Do not operate the electric air pump
longer than 8 minutes without interrup-
tion. Otherwise it may overheat.
You may operate the air pump again af-
ter it has cooled off.
Page 411 of 480

410 Practical hintsFlat tire
Detach the electric air pump.
Stow the electrical plug and the air
hose behind the flap and place the air
pump back in the trunk.Lowering the vehicle
Lower vehicle by turning crank coun-
terclockwise until the full weight of the
vehicle is resting on the ground.
Pull the jack out of the jack support
tube.
1 - 5 Wheel bolts
Tighten the five wheel bolts evenly, fol-
lowing the diagonal sequence illustrat-
ed (1 to 5), until all bolts are tight.
Observe a tightening torque of 96 lb-ft
(130 Nm).
Warning!
G
Follow recommend inflation pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
iThe flat tire may be transported in the
trunk when the retractable hardtop is
raised. Use the protective sheet provid-
ed with the spare wheel. Do not acti-
vate the tire inflation pressure monitor
until the deflated tire has been re-
moved from the vehicle.
Page 412 of 480

411 Practical hints
Flat tire
Before storing the jack in the trunk,
crank back to storage position and fold
in the arm.Replacing jack support tube cover
Slide tongue of cover under the upper
edge of the tube opening.
Applying even pressure, press cover
until it snaps into place.
Be careful not to damage the locking
tabs or clamp the plastic retaining
strap.
MOExtended system*
The MOExtended system allows you to
continue driving your vehicle even if there
is a total loss of pressure in one or more
tires.
You may only use the MOExtended system
in conjunction with the Run Flat Indicator*
(Canada vehicles) (
page 293) or TPMS
(U.S. vehicles) (
page 296).
Warning!
G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
96 lb-ft (130 Nm).Warning!
G
When turning the wheel wrench to tighten
the wheel bolts, make sure you position
hands on the wrench in such a way that you
avoid injury to yourself, such as scraping
your hands against the wheel. Make sure
turning the wheel wrench will not scratch or
damage the wheel rim.
!The maximum distance in emergency
mode depends on the vehicle’s load. It
is 30 miles (50 km) if the vehicle is par-
tially loaded and 18 miles (30 km) if the
vehicle is fully loaded.
The point at which the maximum driv-
ing distance begins in emergency
mode is when the warning message
appears in the multifunction display
indicating that there is a loss of tire
inflation pressure.
Do not exceed the maximum speed of
50 mph (80 km/h).
Page 413 of 480

412 Practical hintsFlat tireWarning!
G
In emergency mode, your vehicle’s driving
characteristics are diminished in such situa-
tions as:
driving around curves
while braking
while accelerating rapidly
Therefore, your driving style must be adapt-
ed accordingly. Avoid abrupt steering and
driving maneuvers, as well as driving over
obstacles (road curbs, potholes, or off-road
areas). This is especially important if the ve-
hicle is heavily loaded.
The emergency driving distance that can be
achieved greatly depends on the demands
placed on the vehicle. Depending on speed,
load, driving maneuvers, road conditions,
outside temperature, etc., the distance can
be significantly shorter or, if the vehicle is
driven cautiously, somewhat longer.
Do not continue driving in emergency mode
if
you notice knocking sounds
the vehicle starts to shake
smoke develops and you smell rubber
ESP
® is intervening continuously
you notice tears on the tire sidewalls
After driving in emergency mode, you must
have the rims inspected by an authorized
Mercedes-Benz Center to check if they are
suitable for further use. The failed tire must
be replaced in any case.iWhen replacing individual or all tires on
the vehicle, make sure only matching
tires marked with “MOExtended” are
mounted in the size specified for your
vehicle (
page 440).
Page 414 of 480
413 Practical hints
Batteries
Batteries
For more information on batteries, see
“Battery” (
page 279).
Your vehicle is equipped with two
batteries:
The starter battery
The battery for electrical consumers
(consumer battery), located in the
trunkThe starter battery is located on the
right-hand side of the engine compart-
ment.
1Positive terminal
2Negative terminalThe consumer battery is located on the
right-hand side of the trunk.
3Positive terminal
4Negative terminal
!The starter battery, its filler caps, and
the vent tube must always be securely
installed when the vehicle is in opera-
tion.
!The consumer battery located in the
trunk is a valve-regulated lead acid
(VRLA) battery, also referred to as
“fleece” battery. Such batteries do not
require topping-up of the electrolyte
level. VRLA batteries therefore do not
Page 415 of 480

414 Practical hintsBatteries
have cell caps and the battery cover is
non-removable. Do not attempt to
open the consumer battery as other-
wise the battery will be damaged.
Even though VRLA batteries do not
require topping-up of the electrolyte
level and cannot be opened to check
the electrolyte level, the battery condi-
tion must be checked periodically by
performing a battery conductance test.
Refer to Maintenance Booklet for bat-
tery condition testing intervals.
As with any other battery, disconnect
the consumer battery if you do not in-
tend to operate your vehicle for an
extended period of time to prevent bat-
tery discharge or connect an accessory
battery charge unit expressly approved
by Mercedes-Benz for your vehicle
model to maintain the battery charge.
Contact an authorized Mercedes-Benz
Center for further information.
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Never lean over batteries while connecting,
you might get 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 explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely damaged.
Have the starter battery checked regu-
larly by an authorized Mercedes-Benz
Center.
Refer to Maintenance Booklet for main-
tenance intervals or contact an autho-
rized Mercedes-Benz Center for further
information.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof batteries only to avoid the
risk of acid burns in the event of an acci-
dent.
Page 416 of 480

415 Practical hints
Batteries
Disconnecting the batteries
Make sure the gear selector lever is set
to position P.
Close the retractable hardtop
(page 195).
Turn off the engine (
page 60).
Turn off all electrical consumers.
Remove the SmartKey from the starter
switch.
or
Vehicles with KEYLESS-GO*: Open the
driver’s door.
Warning!
G
The brake system requires electrical power
to operate.
A malfunction in the vehicle’s power supply
or electrical system may impair brake sys-
tem operation and switch it into its emer-
gency operation mode. The same applies if
battery is disconnected. To brake, the driver
must then apply significantly greater brake
pedal pressure and depress the pedal much
further to obtain the expected braking ef-
fect. If necessary, apply full pressure to the
brake pedal. Brakes are only applied to the
front wheels. Stopping distance is in-
creased! Adjust your driving style according-
ly. For more information, see
“Electro-hydraulic brake system”
(page 88).
Warning!
G
With a disconnected battery
you will no longer be able to turn the
SmartKey in the starter switch and
pressing the KEYLESS-GO* start/stop
button on the gear selector lever will
have no effect
the gear selector lever will remain
locked in positionP
!Always disconnect the batteries in the
order described below, even if you only
want to charge the starter battery, for
example. Otherwise the vehicle’s
electronics can be damaged.