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 279 of 474

277 Operation
Engine compartment
Battery
Your vehicle is equipped with two batter-
ies:
The starter battery (located in the en-
gine compartment)
The battery for electrical consumers 
(located in the trunk)
These batteries should always be suffi-
ciently charged in order to achieve their 
rated service life. Refer to Maintenance 
Booklet for battery maintenance intervals.
If you use your vehicle mostly for 
short-distance trips, you will need to have 
the battery charge checked more frequent-
ly. 
When replacing batteries, always use bat-
teries approved by Mercedes-Benz. 
If you do not intend to operate your vehicle 
for an extended period of time, consult an 
authorized Mercedes-Benz Center about 
steps you need to observe.Batteries contain materials that can harm 
the environment if disposed of improperly. 
Recycling of batteries is the preferred 
method of disposal. Many states require 
sellers of batteries to accept old batteries 
for recycling.
G
Observe all safety instructions 
and precautions when handling 
automotive batteries.
A
Risk of explosion
D
Keep flames or sparks away 
from battery. Do not smoke.
B
Battery acid is caustic. Do not 
allow it to come into contact 
with skin, eyes or clothing.
In case it does, immediately 
flush affected area with clear 
water and seek medical help if 
necessary. 
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this 
Operator's Manual.  
     
        
        Page 311 of 474

309 Operation
Winter driving
Winter driving
Before the onset of winter, have your vehi-
cle winterized at an authorized 
Mercedes-Benz Center. This service in-
cludes:
Check of anticorrosion and antifreeze 
concentration.
Addition of cleaning concentrate to the 
water of the windshield and headlamp 
cleaning system. Add MB Concentrate 
“S” to a pre-mixed windshield washer 
solvent / antifreeze which is formulated 
for temperatures below freezing point 
(page 437).
Battery test. Battery capacity drops 
with decreasing ambient temperature. 
A well charged battery helps to ensure 
that the engine can be started and the 
SBC brake system will be fully opera-
tional even at low ambient tempera-
tures.
Tire change. Mercedes-Benz recom-
mends M+S rated radial-ply tires with a 
minimum tread depth of approximately 1/6in (4 mm) on all four wheels for the 
winter season.
Winter tires
Always use winter tires at temperatures 
below 45°F (7°C) and whenever wintry 
road conditions prevail. Use of winter tires 
is the only way to achieve the maximum ef-
fectiveness of the ABS and ESP in winter 
operation.
For safe handling, make sure all winter 
tires mounted are of the same make and 
have the same tread design. 
!When scraping ice or snow from the 
rear window, be careful not to damage 
the sealing strip or apertures along the 
side of the window. 
Warning!
G
Winter tires with a tread depth of less than 1/6in (4 mm) must be replaced. They are no 
longer suitable for winter operation. 
     
        
        Page 328 of 474

326 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
;
(USA only)
3
(Canada only)
The red brake warning lamp 
comes on while driving and 
you hear a warning sound.
The red brake warning lamp 
comes on while driving 
You are driving with the parking brake set,
or
there is a malfunction in the SBC brake system.
There is insufficient brake fluid in the reservoir.
Release the parking brake 
(page 50).
Read and observe messages in the 
display (
page 335).
Risk of accident! Carefully stop the 
vehicle and notify an authorized 
Mercedes-Benz Center. Do not add 
brake fluid! This will not solve the 
problem.
Warning!
G
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your 
brake system checked immediately if the 
brake warning lamp stays on. Do not add 
brake fluid before checking the brake sys-
tem. 
Overfilling the brake fluid reservoir can re-
sult in spilling brake fluid on hot engine 
parts and the brake fluid catching fire. You 
can be seriously burned.
!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. 
     
        
        Page 329 of 474

327 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
ú
(USA only)
±
(Canada only)
The yellow engine malfunction 
indicator lamp comes on while 
driving.
There is a malfunction in:
The fuel injection system 
The ignition system 
The emission control system 
Systems which effect emissions
Such malfunctions may result in excessive 
emissions values and may switch the engine 
to its limp-home (emergency operation) 
mode.
Have the vehicle checked as soon as 
possible by an authorized 
Mercedes-Benz Center.
An on-board diagnostic connector is 
used by the service station to link the 
vehicle to the shop diagnostics sys-
tem. It allows the accurate identifica-
tion of system malfunctions through 
the readout of diagnostic trouble 
codes. It is located in the front left 
area of the footwell next to the park-
ing brake.
The fuel cap is not closed tightly.
Check the fuel cap (
page 267).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an 
authorized Mercedes-Benz Center. 
     
        
        Page 330 of 474

328 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
ú
(USA only)
±
(Canada only)
The yellow engine malfunction 
indicator lamp comes on while 
driving.
Your fuel tank is empty.
After refuelling, start, turn off, and re-
start the engine three or four times in 
succession. 
The limp-home mode is canceled. You 
do not need to have your vehicle 
checked.
D
The red coolant warning lamp 
comes on when the engine is 
running.
There is insufficient coolant in the reservoir.
If this warning lamp comes on frequently, 
there is a leak in the cooling system.
If the coolant level is correct, the electric ra-
diator fan may be broken. 
Immediately add coolant to prevent 
engine from overheating 
(page 276).
Have the cooling system checked.
If the coolant temperature is below 
248 °F (120 °C), you can continue 
driving to the nearest authorized 
Mercedes-Benz Center.
Avoid high engine loads (e.g. driving 
uphill) and stop-and-go driving.
D
The red coolant warning lamp 
comes on while driving and you 
hear a warning sound.
The coolant temperature has exceeded 
248 °F (120 °C).
Stop as soon as possible and allow 
the engine and coolant to cool down. 
     
        
        Page 333 of 474
331 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
C
The yellow roll bar warning lamp 
comes on or flickers when the 
engine is running.
The roll bar is not operational.
For safety reasons, always have the 
roll bar raised when driving with the 
retractable hardtop open. Attempt to 
raise the roll bar manually.
Have the roll bar checked by an au-
thorized Mercedes-Benz Center.
Warning!
G
If the roll bar warning lamp does not come 
on, does not go out after a long time, flickers 
or comes on while driving as described 
above, then the roll bar system is not oper-
ating properly and may not activate in an ac-
cident. In this case, raise the roll bar 
manually (
page 73) before continuing to 
drive. 
     
        
        Page 342 of 474

340 Practical hintsWhat to do if …Left display
Right display
Possible cause
Possible solution
Distronic
Currently
unavailable.
See Oper. Manual
Distronic* is switched off because
the Distronic* cover in the radiator 
grille is dirty
functionality is impaired by heavy 
rain or thick fog
Clean the Distronic* cover in the radiator 
grille (
page 318).
Restart the vehicle.
or
Distronic* becomes operational again with-
out the engine being started again when the 
conditions that had impaired the functionality 
no longer prevail, e.g. lessening rain or slush 
or snow has fallen off the Distronic* cover 
while driving. You can then operate Distronic* 
as usual again.
Drive to
workshop
Distronic* is malfunctioning or the dis-
play is malfunctioning.
Visit an authorized Mercedes-Benz Center 
as soon as possible.
ESP
Malfunction
Visit
workshop
The ESP has detected a malfunction 
and switched off.
The ABS may not be operational.
The SBC brake system is still function-
ing normally but without the ESP avail-
able.
Continue driving with added caution.
Have the system checked at an authorized 
Mercedes-Benz Center as soon as 
possible.
Failure to follow these instructions increases 
the risk of an accident.