2012 MERCEDES-BENZ SLK-CLASS ROADSTER ECU

Towing and tow-starting
Important safety notes
GWARNING
If you tow the vehicle, you must use a rigid
towing bar if:
R the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the power supply
or the vehicle's electrical system.
The power assistance for the steering and the
brake force booster do not work when the
engine is not running. You will need more
force to steer and brake, you may have to
depress the brake pedal with maximum force.
Before towing away, make sure that the
steering can be moved and is not locked.
If you tow or tow-start another vehicle, its
weight must not exceed the maximum
permissible gross vehicle weight of your
vehicle.
It is better to have the vehicle transported
than to have it towed.
! 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.
! Make sure that the electric parking brake
is released. If the electric parking brake is
faulty, visit a qualified specialist workshop.
! 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,
as this could damage the vehicle. If in
doubt, recover the vehicle with a crane.
! Drive slowly and smoothly when towing.
Excessive tractive power could otherwise
damage the vehicles.
! Do not tow with sling-type equipment.
This could damage the vehicle.
! On vehicles with KEYLESS-GO, use the
SmartKey instead of the Start/Stop
button. Turn the SmartKey to position 2 in
the ignition lock and shift the automatic
transmission to N. Then, turn the SmartKey
back to 0 and leave it in the ignition lock.
When towing a vehicle with an automatic
transmission, the transmission must be in
position N.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the SmartKey to position 2 in
the ignition lock
R cannot shift the transmission to position
N on vehicles with automatic transmission
Vehicles with automatic transmission:
release the selector lever lock manually to
move it out of position P(Y page 146).
i Switch off the automatic locking feature
( Y page 75) You could otherwise be locked
out when pushing or towing the vehicle.
Installing/removing the towing eye
Installing the towing eye
XRemove the towing eye from the vehicle
tool kit ( Y page 274).GWARNING
The exhaust tail pipe may be hot. You could
burn yourself if you touch the tail pipe. Be
particularly careful when removing the rear
cover.
The mountings for the removable towing eyes
are located in the bumpers. They are at the
front and at the rear, under the covers.
Towing and tow-starting287Breakdown assistanceZ

Transporting the vehicle
The towing eye can be used to pull the vehicle
onto a trailer or transporter for transporting
purposes.XVehicles with manual transmission:
shift to neutral.XVehicles with automatic transmission:
turn the SmartKey to position 2 in the
ignition lock.XMove the selector lever to N.
As soon as the vehicle is loaded:
XPrevent the vehicle from rolling away by
applying the parking brake.XVehicles with manual transmission:
shift to first gear or reverse gear.XVehicles with automatic transmission:
move the selector lever to P.XTurn the SmartKey to position 0 in the
ignition lock and remove the SmartKey
from the ignition lock.XSecure the vehicle.
! Only lash the vehicle down by the wheels
or wheel rims, not by parts of the vehicle
such as axle or steering components.
Otherwise, the vehicle could be damaged.
Tow-starting (emergency starting)
When tow-starting your vehicle, it is
important that you follow the safety
instructions ( Y page 287).
! Vehicles with automatic transmission
must not be started by tow-starting. This
could otherwise damage the transmission.
For further information on "Jump-starting"
see ( Y page 285).
Before tow-starting the following conditions
must be fulfilled:
R the battery is connected.
R the engine has cooled down.
R the catalytic converter has cooled down.
XSwitch on the hazard warning lamps
( Y page 108).XInstall the towing eye ( Y page 287).XSecure the rigid towing bar or the towing
rope.XDepress and hold the brake pedal.XTurn the SmartKey to position 2 in the
ignition lock.XDepress the clutch pedal and keep it
depressed.XShift to neutral.XRelease the brake pedal.XTow-start the vehicle.XShift to second gear.XRelease the clutch pedal slowly; do not
depress the accelerator pedal while doing
so.
The engine is started.XDepress the clutch pedal and shift to
neutral.XStop at a suitable place.XDepress the parking brake.XRemove the rigid towing bar or towing rope.XRemove the towing eye ( Y page 288).XSwitch off the hazard warning lamps.
Fuses
Important safety notes
GWARNING
Only use fuses that have been approved for
Mercedes-Benz vehicles and that have the
correct fuse rating for the systems
concerned. Do not attempt to repair or bridge
faulty fuses. Using fuses that have not been
approved or attempting to repair or bridge
faulty fuses could cause the fuse to be
overloaded and result in a fire. Have the cause
traced and rectified at a qualified specialist
workshop.
The fuses in your vehicle serve to close down
faulty circuits. If a fuse blows, all the
Fuses289Breakdown assistanceZ

Checking the tire pressures
Important safety notes
Observe the "Tire pressure information"
section ( Y page 297).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading
Information placard on the B-pillar
R on the tire pressure label on the fuel filler
flap
R in the "Tire pressure information" section
Checking tire pressures manually
To determine and set the correct tire
pressure, proceed as follows:
XRemove the valve cap of the tire that is to
be checked.XPress the tire pressure gauge securely onto
the valve.XRead the tire pressure and compare it with
the recommended value on the Tire and
Loading Information placard on the
B-pillar on the driver's side of your vehicle.XIf necessary, increase the tire pressure to
the recommended value ( Y page 297).XIf the tire pressure is too high, release air
by pressing down the metal pin in the valve
using the tip of a pen, for example. Then
check the tire pressure again using the tire
pressure gauge.XScrew the valve cap onto the valve.XRepeat these steps for the other tires.
Tire pressure monitor (USA only)
Important safety notes
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
( Y page 297). Note that the correct tire
pressure for the current operating situation
must first be taught-in to the tire pressure
monitor. If there is a substantial loss of
pressure, the warning threshold for the
warning message is aligned to the reference
values taught-in. Restart the tire pressure
monitor after adjusting the pressure of the
cold tires ( Y page 303). The current
pressures are saved as new reference values.
As a result, a warning message will appear if
the tire pressure drops significantly.
The tire pressure monitor does not warn you
of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
( Y page 297).
The tire pressure monitor is not able to warn
you of a sudden loss of pressure, e.g. if the
tire is penetrated by a foreign object. In the
event of a sudden loss of pressure, bring the
vehicle to a halt by braking carefully. Avoid
abrupt steering maneuvers.
If a tire pressure monitor system is installed,
the vehicle's wheels have sensors that
monitor the tire pressures in all four tires. The
tire pressure monitor warns you if the
pressure drops in one or more of the tires. The
tire pressure monitor only functions if the
correct sensors are installed to all wheels.
The tire pressure monitor has a yellow
warning lamp in the instrument cluster for
indicating pressure loss or a malfunction.
Whether the warning lamp flashes or lights up
indicates whether a tire pressure is too low or
the tire pressure monitoring system is
malfunctioning:
R if the warning lamp is lit continuously, the
tire pressure on one or more tires is
significantly too low. The tire pressure
monitor is not malfunctioning.
R if the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.GWARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
Tire pressure301Wheels and tiresZ

Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa
corresponds to 1 psi. Another unit for tire
pressure is bar. There are 100 kilopascals
(kPa) to 1 bar.
Load index
In addition to the load-bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifies the load-bearing
capacity more precisely.
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 system and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage.
Maximum load rating
The maximum load rating in kilograms or
pounds is the maximum weight 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
outward force to each square inch of the tire's
surface. 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.
Tire pressure of cold tires
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if the vehicle has not been driven more 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
part and more than 2.3 kg (5 lb). These
314Definition of terms for tires and loadingWheels and tires