Page 90 of 474

88 Safety and SecurityAnti-theft systemsImmobilizer
The immobilizer prevents unauthorized 
persons from starting your vehicle.
Activating
With the SmartKey
Remove the SmartKey from the starter 
switch.
With KEYLESS-GO*
Press the start/stop button on the gear 
selector lever once.
The engine is turned off.
Open the driver’s door.Deactivating
With the SmartKey
Turn the SmartKey in the starter switch 
to position2 (
page 36).
With KEYLESS-GO*
Switch on the ignition (
page 38).
Anti-theft alarm system
Once the alarm system has been armed, a 
visual and audible alarm is triggered when 
someone opens 
a door
the trunk lid
the hood
a storage compartment in the rear
the glove box
the storage compartment under the 
armrest
The alarm will stay on, even if the activat-
ing element (a door, for example) is imme-
diately closed.
iStarting the engine will also deactivate 
the immobilizer.
In case the engine cannot be started 
(yet the vehicle’s battery is charged), 
the system is not operational. Contact 
an authorized Mercedes-Benz Center 
or call 1-800-FOR-MERCedes (in the 
USA), or 1-800-387-0100 (in Canada). 
     
        
        Page 133 of 474

131 Controls in detail
Instrument cluster
Instrument cluster
For a full view illustration of the instrument 
cluster, see “Instrument cluster” 
(page 24).
The instrument cluster is activated when 
you
open a door
switch on the ignition
press the reset button (
page 24)
switch on the exterior lamps
Opening a door will activate the instrument 
cluster only for about 30 seconds.
You can change the instrument cluster set-
tings in the Instrument cluster submenu of 
the control system (
page 148).
Instrument cluster illumination
Use the reset button to adjust the illumina-
tion brightness for the instrument cluster 
and the switches on the center console.
To brighten illumination
Turn the reset button in the instrument 
cluster (
page 24) clockwise.
The instrument cluster illumination will 
brighten.
To dim illumination
Turn the reset button in the instrument 
cluster (
page 24) counterclockwise.
The instrument cluster illumination will 
dim.
Coolant temperature gauge
iThe instrument cluster illumination is 
dimmed or brightened to suit ambient 
light conditions.
Warning
G
Driving when your engine is badly over-
heated can cause some fluids which 
may have leaked into the engine com-
partment to catch fire. You could be se-
riously burned.
Steam from an overheated engine can 
cause serious burns an can occur just by 
opening the hood. Stay away from the 
engine if you see or hear steam coming 
from it.
Turn off the engine, get out of the vehicle 
and do not stand near the vehicle until the 
engine has cooled down. 
     
        
        Page 268 of 474

266 OperationDriving instructions
Coolant temperature
During severe operating conditions, e.g. 
stop-and-go city traffic, the coolant tem-
perature may rise close to approx. 266°F 
(130°C).
The engine should not be operated with 
the coolant temperature over 248°F 
(120°C). Doing so may cause serious en-
gine damage which is not covered by the 
Mercedes-Benz Limited Warranty.
Warning!
G
Inhalation of exhaust gas is hazardous to 
your health. All exhaust gas contains carbon 
monoxide, and inhaling it can cause uncon-
sciousness and lead to death.
Do not run the engine in confined areas 
(such as a garage) which are not properly 
ventilated. If you think that exhaust gas 
fumes are entering the vehicle while driving, 
have the cause determined and corrected 
immediately. If you must drive under these 
conditions, drive only with at least one win-
dow fully open at all times.
Warning!
G
Driving when your engine is badly over-
heated can cause some fluids, which 
may have leaked into the engine com-
partment, to catch fire. You could be se-
riously burned.
Steam from an overheated engine can 
cause serious burns and can occur just 
by opening the engine hood. Stay away 
from the engine if you see or hear steam 
coming from it. Turn off the engine, get 
out of the vehicle and do not stand near 
the vehicle until the engine has cooled 
down. 
     
        
        Page 271 of 474

269 Operation
At the gas station
Check regularly and before a long trip
For information on quantities and require-
ments of operating agents, see “Fuels, 
coolants, lubricants, etc.” (
page 431).
Open the hood (
page 270).
1Windshield washer and headlamp 
cleaning system
2Brake fluid
3Coolant levelWindshield washer and headlamp 
cleaning system
For information on refilling the reservoir, 
see “Windshield washer system and 
headlamp cleaning system” (
page 278).
Brake fluid
For information on brake fluid, see “Fuels, 
coolants, lubricants, etc.” (
page 431).Coolant level
For information on checking the coolant 
level, see “Coolant” (
page 276).
Engine oil level
For more information on checking the en-
gine oil level, see “Checking engine oil lev-
el with the control system” (
page 272).
Vehicle lighting
Check function and cleanliness. For more 
information, see “Replacing bulbs” 
(
page 380).
Exterior lamp switch see “Switching on 
headlamps” (
page 51).
Tire inflation pressure
For information on checking the tire infla-
tion pressure, see “Checking tire inflation 
pressure” (
page 290).
!If you find that the brake fluid in the 
brake fluid reservoir has fallen to the 
minimum mark or below, have the 
brake system checked for brake pad 
thickness and leaks immediately. Noti-
fy an authorized Mercedes-Benz Center 
immediately. Do not add brake fluid as 
this will not solve the problem. For 
more information, see the “Practical 
hints” section (
page 349). 
     
        
        Page 272 of 474
270 OperationEngine compartmentHood
Opening
1Hood release
Pull lever1 downwards.
The hood is unlocked.
2Lever for opening the hood
Push lever2 on the hood upwards. 
Pull up on the hood and then release it. 
The hood will be automatically held 
open at shoulder height by gas-filled 
struts. 
Warning!
G
Do not pull the release lever while the vehi-
cle is in motion. Otherwise the hood could 
be forced open by passing air flow. 
!To avoid damage to the windshield wip-
ers or hood, never open the hood if the 
wiper arms are folded forward away 
from the windshield. 
Warning!
G
To help prevent personal injury, stay clear of 
moving parts when the hood is open and the 
engine is running. Make sure the hood is 
properly closed before driving. When closing 
the hood, use extreme caution not to catch 
hands or fingers.
The radiator fan may continue to run for ap-
proximately 30 seconds or may even restart 
after the engine has been turned off. Stay 
clear of fan blades. 
     
        
        Page 273 of 474

271 Operation
Engine compartment
Closing
Let the hood drop from a height of ap-
proximately 1
1/2ft (50 cm). 
The hood will lock audibly.
Check to make sure the hood is fully 
closed. 
If you can raise the hood at a point 
above the headlamps, then it is not 
properly closed. Open it again and let it 
drop with somewhat greater force.
Warning!
G
If you see flames or smoke coming from the 
engine compartment, or if the coolant tem-
perature gauge indicates that the engine is 
overheated, do not open the hood. Move 
away from the vehicle and do not open the 
hood until the engine has cooled. If neces-
sary, call the fire department.
Warning!
G
The engine is equipped with a transistorized 
ignition system. Because of the high voltage 
it is dangerous to touch any components (ig-
nition coils, spark plug sockets, diagnostic 
socket) of the ignition system
with the engine running
while starting the engine
if ignition is “on” and the engine is 
turned manually
Warning!
G
Be careful that you do not close the hood on 
anyone. 
     
        
        Page 278 of 474

276 OperationEngine compartmentCoolantThe engine coolant is a mixture of water 
and anticorrosion/antifreeze. To check 
the coolant level, the vehicle must be 
parked on level ground and the engine 
must be cool. 
The coolant expansion tank is located on 
the passenger side of the engine compart-
ment. 
1Coolant expansion tank
Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease any excess pressure.
Continue turning the cap to the left and 
remove it.
The coolant level is correct if the level 
for cold coolant: is up to the upper 
mark on the bracing rib of the coolant 
expansion tank (translucent)
for warm coolant: is approx. 0.6 in 
(1.5 cm) higher
Add coolant as required.
Replace and tighten cap. 
For more information, see “Coolants” 
(
page 435).
Warning!
G
In order to avoid any possibly serious burns:
Use extreme caution when opening the 
hood if there are any signs of steam or 
coolant leaking from the cooling system, 
or if the coolant temperature gauge indi-
cates that the coolant is overheated.
Do not remove pressure cap on coolant 
reservoir if coolant temperature is 
above 158°F (70°C). Allow engine to 
cool down before removing cap. The 
coolant reservoir contains hot fluid and 
is under pressure.
Using a rag, slowly open the cap approx-
imately 
1/2 turn to relieve excess pres-
sure. If opened immediately, scalding 
hot fluid and steam will be blown out un-
der pressure.
Do not spill antifreeze on hot engine 
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.
!SL 600 and SL 65 AMG: Only open the 
cap on coolant expansion tank1. 
Never open the cap between the two 
charge-air coolers. Otherwise, the en-
gine could be damaged. 
     
        
        Page 331 of 474
329 Practical hints
What to do if …
Warning!
G
Driving when your engine is badly overheat-
ed can cause some fluids which may have 
leaked into the engine compartment to 
catch fire. You could be seriously burned.
Steam from an overheated engine can cause 
serious burns and can occur just by opening 
the engine hood. Stay away from the engine 
if you see or hear steam coming from it.
Turn off the engine, get out of the vehicle 
and do not stand near the vehicle until the 
engine has cooled down.