battery MERCEDES-BENZ SL ROADSTER 2018 Service Manual

XStart the engine of the donor vehicle and run it at idling speed.
XConnect negative terminal?of donor battery Bto ground point Aof your vehicle using the
jumper cable, connecting the jumper cable to battery of other vehicle Bfirst.
XStart the engine.
XBefore disconnecting the jumper cables, let the engine run for several minutes.
XFirst, remove the jumper cables from ground point Aand negative terminal ?, then from pos-
itive terminal ;and positive terminal =. Begin each time at the contacts on your own vehicle
first.
XAfter the jumper cable is removed, return cover :of positive terminal ;to the original position.
Positive terminal ;is covered up and thus insulated again.
XHave the battery checked at a qualified specialist workshop.
Jump-starting is not considered to be a normal operating condition.
iJumper cables and further information regarding jump-starting can be obtained at any qualified
specialist workshop.
Towing and tow-starting
Important safety notes
GWARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissible
gross weight of your vehicle, the:
Rthe towing eye could detach itself
Rthe vehicle/trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per- missible gross weight of your vehicle.
Details on the permissible gross vehicle weight
of your vehicle can be found on the vehicle iden-
tification plate (
Ypage 311).
!When Active Brake Assist, Distance Pilot
DISTRONIC or the HOLD function is activated,
the vehicle brakes automatically in certain
situations.
To avoid damage to the vehicle, deactivate
these systems in the following or similar sit-
uations:
Rwhen towing the vehicle
Rin the car wash
!Only secure the tow rope or tow bar at the
towing eyes. Otherwise, the vehicle could be
damaged.
!Do not use the towing eye for recovery, this
could damage the vehicle. If in doubt, recover
the vehicle with a crane.
!When towing, pull away slowly and
smoothly. If the tractive power is too high, the
vehicles could be damaged.
!Do not tow with sling-type equipment. This
could damage the vehicle.
!When towing away vehicles with KEYLESS-
GO, us e the key instead of the Start/Stop
button. The automatic transmission may oth- erwise shift to position jwhen you open the
driver's or front-passenger door, which could
damage the transmission.
!Make sure that the electric parking brake is
released. If the electric parking brake is faulty,
visit a qualified specialist workshop.
!The vehicle can be towed a maximum of
30 miles (50km). The towing speed of 30 mph
(50 km/h) must not be exceeded.
If the vehicle has to be towed more than
30 miles (50km), the entire vehicle must be
raised and transported.
!If you tow or tow-start another vehicle, its
weight must not exceed the maximum per-
missible gross vehicle weight of your vehicle.
It is better to have the vehicle transported than
to have it towed away.
The automatic transmission must be in position
i when the vehicle is being towed away.
280Towing and tow-starting
Breakdown assistance

The battery must be connected and charged.
Otherwise, you:
Rcannot turn the SmartKey to position2in
the ignition lock.
Rcannot shift the automatic transmission to
position i.
Deactivate the automatic locking feature before
the vehicle is towed (
Ypage 196). You could
otherwise be locked out when pushing or towing
the vehicle.
Installing/removing the towing eye
Installing the towing eye
GWARNING
The exhaust tail pipe may be very hot. There is
a risk of burns when removing the rear cover.
Do not touch the exhaust pipe. Take particular
care when removing the rear cover.
The brackets for the screw-in towing eye are
located in the bumpers. They are at the front and
at the rear, behind the covers.
XRemove the towing eye from the vehicle tool
kit (Ypage 270).
XFront bumper: insert a finger into the recess
on the bottom edge of cover :.
XPull cover:out of the bumper towards you
in the direction of the arrow.
Cover :is attached to the opening with a
strap.
XRear bumper: press the mark on cover :
inwards in the direction of the arrow.
XRemove cover :from the opening.
XScrew in the towing eye clockwise as far as it
will go and tighten it.
Removing the towing eye
XUnscrew and remove the towing eye.
XFront bumper: position cover:on the
opening in the bumper.
XTo close, press the lower section of cover :.
XRear bumper:position cover:with the tab
on the opening in the bumper.
XTo close, press the lower section of cover :
until it engages.
XPlace the towing eye in the vehicle tool kit.
Towing a vehicle with both axles on
the ground
GWARNING
You can no longer steer the vehicle if the
steering wheel lock has been engaged. There
is a risk of an accident.
Always switch off the ignition when towing the
vehicle with a tow cable or a tow bar.
The automatic transmission shifts to position
j automatically when you open the driver's or
front-passenger door or when you remove the
SmartKey from the ignition lock.
In order to ensure that the automatic transmis-
sion stays in position iwhen towing away the
vehicle, you must observe the following points:
XSwitch on the hazard warning lamps
(Ypage 108).
XMake sure that the vehicle is stationary and
that the SmartKey is in position uin the
ignition lock.
XTurn the SmartKey to position 2in the igni-
tion lock.
On vehicles with KEYLESS-GO, use the Smart-
Key instead of the Start/Stop button
(
Ypage 122).
XDepress and hold the brake pedal.
XShift the transmission to position i.
XRelease the brake pedal.
Towing and tow-starting281
Breakdown assistance
Z

Curb weight
The weight of a vehicle with standard equipment
including the maximum capacity of fuel, oil and
coolant. It also includes the air-conditioning sys-
tem and optional equipment if these are instal-
led in the vehicle, but does not include passen-
gers or luggage.
Maximum load rating
The maximum load rating is the maximum per-
missible weight in kilograms or lbs for which a
tire is approved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one tire.
Maximum load on one tire
Maximum load on one tire. This is calculated by
dividing the maximum axle load of one axle by
two.
PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire width
in percent.
Tire pressure
This is pressure inside the tire applying an out-
ward force to each square inch of the tire's sur-
face. The tire pressure is specified in pounds per
square inch (psi), in kilopascal (kPa) or in bar.
The tire pressure should only be corrected when
the tires are cold.
Cold tire pressure
The tires are cold:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
Rif the vehicle has not been driven further than
1 mile (1.6 km)
Tread
The part of the tire that comes into contact with
the road.
Bead
The tire bead ensures that the tire sits securely
on the wheel. There are several steel wires in the
bead to prevent the tire from coming loose from the wheel rim.
Sidewall
The part of the tire between the tread and the
bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs).Thes e
option al extras, such as high-performance
brakes, level control, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used by
a tire manufacturer to identify tires, for example
for a product recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur-
er's identity code, tire size, tire type code and
the manufacturing date.
Load bearing index
The load bearing index (also load index) is a code
that contains the maximum load bearing capa-
city of a tire.
Traction
Traction is the result of friction between the tires
and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of áin (1.6 mm)
has been reached.
Occupant distribution
The distribution of occupants in a vehicle at their
designated seating positions.
Total load limit
Nominal load and luggage load plus 68 kg
(150 lbs) multiplied by the number of seats in
the vehicle.
Changing a wheel
Flat tire
The "Breakdown assistance" section
(Ypage 271) contains information and notes on
how to deal with a flat tire. Information on driv-
ing with MOExtended tires in the event of a flat
Changing a wheel303
Wheels and tires
Z