2008 MERCEDES-BENZ SL550 check engine

387 Practical hints
What to do if …
When the message Add 1 qt engine oil
at next refueling
(Canada: 1 liter)
appears while the engine is running and at
operating temperature, the engine oil level
has dropped to approximately the
minimum level.
When this occurs, the warning is at first
intermittent and then remains on if the oil
level drops further.Visually check for oil leaks. If there are no
obvious oil leaks, drive to the nearest
service station to refill the engine oil
should be topped to the required level.
For information on approved engine oils,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Center.
Left displayRight displayPossible cause/consequencePossible solution
NUSA only:
Add 1 qt
engine oil
at next
refueling.
Canada only:
Add 1 liter
engine oil
at next
refueling.
Vehicles with engine oil measuring
system only:
The engine oil level is too low.Add engine oil (page 286) and check the
engine oil level (
page 284).
!Engine oil level warnings should not be ig-
nored. Extended driving with the symbol
displayed could result in serious engine damage
that is not covered by the Mercedes-Benz
Limited Warranty.

388 Practical hints
What to do if …
Left displayRight displayPossible cause/consequencePossible solution
NEngine Oil Level
Stop car,
switch engine off.There is no oil in the engine. There
is a danger of engine damage.Stop the vehicle in a safe location or as soon
as it is safe to do so.
Turn off the engine.
Add engine oil (page 286) and check the
engine oil level (
page 284).
Engine Oil Level
Reduce Oil LevelVehicles with engine oil measuring
system only:
You have added too much engine
oil. There is a risk of damaging the
engine or the catalytic converter.Have excess oil siphoned or drained off.
Observe all legal requirements with respect
to its disposal.
Engine Oil Level
Cannot
measure
eng. oil level.Vehicles with engine oil measuring
system only:
The measuring system is malfunc-
tioning.Have the measuring system checked by an
authorized Mercedes-Benz Center.
Engine Oil Level
Check LevelVehicles with oil dipstick only:
The engine oil has dropped to a crit-
ical level.Check the engine oil level (page 284) and
add oil as required (
page 286).
If you must add engine oil frequently, have the
engine checked for possible leaks.

389 Practical hints
What to do if …
Left displayRight displayPossible cause/consequencePossible solution
AFuel Cap
OpenA loss of pressure has been detect-
ed in the fuel system. The fuel cap
may not be closed properly or the
fuel system may be leaky.Check the fuel cap (page 279).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an autho-
rized Mercedes-Benz Center.
KRetract. Roof Oper.
Please Wait
See Oper. Manual
The on-board voltage is too low.Start the engine.
The hardtop drive system was shut
down for safety reasons after multi-
ple, consecutive attempts to raise
or lower the hardtop.After about 10 minutes you can open or close the
retractable hardtop.
Switch on the ignition (page 40).
Repeat the opening or closing procedure.
Retractable Roof
LoweringThe retractable hardtop is not com-
pletely opened or closed. The roof
hydraulics will start to lose pres-
sure.Make sure the retractable hardtop is com-
pletely opened or closed (
page 204).
Retractable Roof
Operation
Only At StandstillYou have attempted to open the re-
tractable hardtop while driving.Stop the vehicle in a safe location and try to
open the hardtop again.

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.

428 Practical hints
Batteries
!The factory-equipped VRLA battery is
leak-proofed. Only use a battery as replacement
that has the same security features and is of
identical size, voltage, and capacity as the
factory-equipped battery.
The battery, the battery ventilation and the
lateral plug must always be securely installed
when the vehicle is in operation.
Warning!G
Failure to follow these instructions can
result 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 terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the starter battery checked regularly by an
authorized Mercedes-Benz Center.
Refer to Maintenance Booklet for maintenance
intervals or contact an authorized
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.
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 increased! Adjust your
driving style accordingly. For more informa-
tion, see “Electro-hydraulic brake system”
(
page 94).

432 Practical hints
Jump starting
If the starter battery is discharged, the en-
gine can be started with jumper cables and
the battery of another vehicle. Observe the
following:

Jump starting should only be performed
when the engine and catalytic
converter are cold.

Do not start the engine if the battery is
frozen. Let the battery thaw out first.

Only jump start from batteries with the
same voltage rating (12 V). Jump start-
ing with a higher voltage battery could
damage the vehicle’s electrical system,
which will not be covered by the
Mercedes-Benz Limited Warranty.

Only use jumper cables with sufficient
cross section and insulated terminal
clamps.

Always make sure the jumper cables
are not on or near pulleys, fans, or
other parts that move when an engine
is started or running.
Warning!G
Failure to follow these directions will cause
damage to the electronic components, and
can lead to a battery explosion and severe
injury or death.
Never lean over batteries while connecting
or jump starting, 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 very explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
Attempting to jump start a frozen battery
can result in it exploding, causing personal
injury.
Read all instructions before proceeding.
!Do not tow-start the vehicle.
!Jump starting may only be performed on the
battery installed in the engine compartment.
Avoid repeated and lengthy starting attempts.
Do not attempt to start the engine using a bat-
tery quick charge unit.
If the engine does not run after several unsuc-
cessful starting attempts, have it checked at the
nearest authorized Mercedes-Benz Center.
Excessive unburned fuel generated by repeated
failed starting attempts may damage the
catalytic converter and may present a fire risk.
Make sure the jumper cables do not have loose
or missing insulation.
Make sure the cable clamps do not touch any
other metal part while the other end is still
attached to a battery.

433 Practical hints
Jump starting
The starter battery is located on the right
side of the engine compartment.
Make sure the two vehicles do not
touch.
Turn off all electrical consumers.
Apply the parking brake (page 63).
Make sure the gear selector lever is set
to position P (
page 172).
Open the hood (page 282).
Remove the red cover from positive ter-
minal on both vehicles (
page 427).1Positive terminal of charged battery
2Positive terminal of discharged battery
3Negative terminal of discharged
battery
4Negative terminal of charged battery
Connect positive terminals 1 and 2
of the batteries with the red jumper
cable. Clamp cable to charged battery
first.
Start the engine of the vehicle with the
charged battery and run at idle speed.
Connect negative terminals 3 and 4
of the batteries with the black jumper
cable. Clamp cable to charged battery
first.
Start the engine of the disabled vehi-
cle.
You can now turn on the electrical con-
sumers. Do not switch on the headlamps
under any circumstances.
Remove the jumper cables first from
negative terminals 4 and 3 and then
from positive terminals 2 and 1.
You can now switch on the headlamps.
Have the battery checked at the near-
est authorized Mercedes-Benz Center.
Warning!G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 290).
!Never invert the terminal connections.

438 Practical hints
Fuses
Fuse boxes in engine compartment
Open the hood (page 282).
The fuse boxes are located on the driver’s
and passenger side in front of the bulk-
head (wall separating the engine and
passenger compartment).
Fuse box on driver’s side
1Fuse box cover
2Locking
3Unlocking
Fuse box on passenger side
1Fuse box cover
2Locking
3UnlockingOpening
Move slide to position 3 and lift
cover1.
Closing
Hook cover 1 onto tabs and close it.
Move slide to position 2.
Close the hood after checking or
replacing fuses (
page 283).
!The fuse box cover must be properly
positioned with the slide at the ‹symbol to
prevent moisture or dirt from entering the fuse
box and possibly impairing fuse operation.