2008 MERCEDES-BENZ SL55AMG trunk

427 Practical hints
Batteries
Batteries
For more information on batteries, see
“Battery” (
page 290).
Your vehicle is equipped with two
batteries:

The starter battery

The battery for electrical consumers
(consumer battery), located in the
trunk
The starter battery is located on the
right-hand side of the engine compart-
ment.
1Positive terminal
2Negative terminal
3Battery ventilationThe consumer battery is located on the
right-hand side of the trunk.
4Positive terminal
5Negative terminal
!The starter battery, its filler caps, and the
ventilation hose must always be securely
installed when the vehicle is in operation.!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 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 top-
ping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the bat-
tery condition must be checked periodically by
performing a battery conductance test. Refer to
Maintenance Booklet for battery condition test-
ing intervals.
As with any other battery, disconnect the con-
sumer battery if you do not intend to operate
your vehicle for an extended period of time to
prevent battery discharge or connect an acces-
sory battery charge unit expressly approved by
Mercedes-Benz for your vehicle model to main-
tain the battery charge. Contact an authorized
Mercedes-Benz Center for further information.

429 Practical hints
Batteries
Disconnecting the batteries
Apply the parking brake (page 63).
Make sure the gear selector lever is set
to position P (
page 172).
Close the retractable hardtop
(
page 204).
Turn off all electrical consumers.
Turn off the engine (page 64).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*: Open
the driver’s door.
Open the trunk.
Read and observe safety instructions
and precautions (
page 290).
Open the luggage cover in the trunk
(
page 211).
Remove the trunk floor.
The battery for electrical consumers is
located in the right hand area of the
trunk (
page 400).
Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
negative lead from negative
terminal5 of the consumer battery
(
page 427).
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.


430 Practical hints
Batteries
Open the hood (page 282).
Use the 10 mm open-end wrench from
the vehicle tool kit to disconnect the
negative lead from negative
terminal2 of the starter battery
(
page 427).
Remove the covers from the positive
terminals 1 and 4 (
page 427).
Disconnect the positive lead from pos-
itive terminal 4 of the consumer bat-
tery (
page 427).
Disconnect the positive lead from pos-
itive terminal 1 of the starter battery
(
page 427).
Removing the batteries
Removing the consumer battery
Remove the screws securing the bat-
tery in the trunk.
Remove the battery support and
bracket.
Pull out the battery ventilation hose
from the battery.
Depending on battery arrangement in
your vehicle model, the ventilation tube
is located either on the left or right side
of the battery.
Take out the battery.
Removing the starter battery
Remove the screws securing the start-
er battery in the engine compartment.
Pull battery ventilation 3
(
page 427) out of the battery.
Lift the retaining bracket.
Remove the battery.
Charging and reinstalling batteries
Warning!G
Never charge a battery while still installed in
the vehicle unless the accessory battery
charge unit approved by Mercedes-Benz is
being used. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
An accessory battery charge unit specially
adapted for Mercedes-Benz vehicles and
tested and approved by Mercedes-Benz is
available, permitting the charging of the
battery in its installed position. Contact an
authorized Mercedes-Benz Center for infor-
mation and availability. Charge battery in
accordance with the separate instructions
for the accessory battery charger.


431 Practical hints
Batteries
Charge batteries in accordance with
the instructions of the battery charger
manufacturer.
Reinstall the charged batteries. Follow
the previously described steps in re-
verse order.
Reconnecting the batteries
Turn off all electrical consumers.
Install starter battery in the designated
location in the engine compartment.
Install consumer battery in the desig-
nated location in the trunk.
Attach supports and brackets.
Tighten support and bracket screws.
Connect positive lead 4 (page 427)
of the consumer battery and positive
lead 1 (
page 427) of the starter bat-
tery and fasten covers.
Connect negative lead 2
(
page 427) of the starter battery.
Connect negative lead 5
(
page 427) of the consumer battery.
Reinstall the trunk floor.
Close trunk luggage cover
(
page 211).
!Always connect the batteries in the order
described below. Otherwise the vehicle’s elec-
tronics can be damaged.
!Never invert the terminal connections!
iThe following procedures must be carried
out following any interruption of battery power
(e.g. due to reconnection):

Synchronize the ESP® (page 367).

Synchronize side windows (page 203).

437 Practical hints
Fuses
Fuses
The electrical fuses in your vehicle serve to
switch off malfunctioning power circuits.
If a fuse is blown, the components and sys-
tems secured by that fuse will stop operat-
ing.If a newly inserted fuse blows again, have
the cause determined and rectified by an
authorized Mercedes-Benz Center.
A fuse chart explains the fuse allocation
and fuse amperages. It is located in the
trunk with the vehicle tool kit
(
page 400).
The electrical fuses are located in different
fuse boxes:

on the driver’s side of the engine com-
partment (
page 438)

on the passenger side of the engine
compartment (
page 438)

under passenger-side rear storage
compartment (
page 439)

in the trunk (page 439)Before replacing fuses:
Apply the parking brake (page 63).
Make sure the gear selector lever is set
to position P (
page 172).
Turn off all electrical consumers.
Turn off the engine (page 64).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*: Open
the driver’s door.
Warning!G
Only use fuses approved by Mercedes-Benz
with the specified amperage for the system
in question and do not attempt to repair or
bridge a blown fuse. Using other than
approved fuses or using repaired or bridged
fuses may cause an overload leading to a
fire, and/or cause damage to electrical
components and/or systems. Have the
cause determined and remedied by an
authorized Mercedes-Benz Center
iA blown fuse must be replaced by an appro-
priate spare fuse (recognizable by its color or the
fuse rating given on the fuse) of the amperage
recommended in the fuse chart.
Any Mercedes-Benz Center will be glad to advise
you on this subject.
iIn case of a blown fuse contact Roadside
Assistance or an authorized Mercedes-Benz
Center.

439 Practical hints
Fuses
Fuse box in passenger compartment
The fuse box is located under the rear
passenger-side storage compartment.
1Clips
2Storage compartment floor
Open the rear passenger-side storage
compartment (
page 240).
Lift both clips 1.
Remove storage compartment floor 2
in direction of arrow.
You can now access the fuses.
To reinstall storage compartment
floor2 after checking or replacing
fuses, follow the procedure in reverse
order.
Fuse in trunk
The fuse in the trunk is located on the
right-hand side of the trunk.
Lift up the trunk floor cover.
Emergency engine shut-down
If the engine cannot be turned off as
described, you may use the following
emergency procedure.
Take the fuse chart from the vehicle
tool kit (
page 400).
Find row “Engine emergency stop” in
the fuse chart table to identify the
fuses that have to removed as well as
their locations.
Remove the respective fuses.

456 Technical data
Weights
Trunk load max.220 lbs (100 kg)

469 Index
Brake system
Messages in the multifunction
display 382
Brakes 268
BAS 91
Brake fluid 280, 458, 460
Electro-hydraulic brake system 94
High-performance brake system
(AMG vehicles only) 270
Warning lamp 345
Break-in period 266
Bulbs
Messages in the multifunction
display 392
Replacing 409
C
California retail buyers and lessees,
important notice for 11
Call priority, Tele Aid 256
Capacities and recommended
fuel/lubricants 457
Cargo area see Trunk
Carpets, cleaning 339
Catalytic converter 277
CD changer 155, 240CD player
Operating 155
Center console
Lower part 32
Upper part 31
Central locking
Automatic 122, 166
Central locking/unlocking
switch 31, 122
Locking/unlocking from inside 122
Certification label 444
Check engine see Lamps, indicator and
warning
Checking tire pressure electronically with
the Advanced Tire Pressure Monitoring
System (Advanced TPMS)*, (Canada
only) 308
Children in the vehicle
Air bags 84
Infant and child restraint systems 84
Occupant Classification System
(OCS) 74
Passenger front air bag off indicator
lamp 78, 357
Cigarette lighter 244
Clock 25, 161Cockpit 24
Cold tire inflation pressure 323
Collapsible tire (spare wheel) 453
COMAND system 31
Driving instructions 276
Combination switch
High beam 57, 135
Turn signals 57
Windshield wipers 58
Consumer battery 290
Control and operation of radio
transmitters 276
Control system 143, 146
Control system menus
AMG 150
AUDIO 153
Distronic* 156, 222
NAV 155
Settings 157
Standard display 149
TEL* 169
Trip computer 167
Vehicle status message memory 156