Page 76 of 304

76 Controls in detailLocking and unlocking
Checking the batteries
Press button
‹
 or
Œ
 longer than 
1second.
The battery check lamp4 lights up 
briefly to indicate that the key batteries 
are in order.
Warning!
G
When leaving the vehicle, always remove the 
key from the steering lock and lock the vehi-
cle. Do not leave children unattended in the 
vehicle, or with access to an unlocked vehi-
cle. It is possible for children to open a 
locked door from the inside, which could re-
sult in an accident and/or serious injury.
!If you can no longer lock or unlock the 
vehicle with the remote control, then 
either the batteries in the remote con-
trol are discharged, the remote control 
is malfunctioning, or the vehicle battery 
is drained.
Check the batteries in the remote 
control and replace them if neces-
sary (
page 212)
or
Synchronize the remote control 
(page 213)
or
Use the folding key to unlock the 
doors (
page 210) and the trunk 
(
page 210) as required. Lock the 
vehicle using the folding key 
(page 211).
If the remote control is malfunctioning, 
contact an authorized Mercedes-Benz 
Center.
!If battery check lamp4 does not light 
up briefly during the check, then the re-
mote control batteries are discharged.
Replace the batteries (
page 212). 
You can obtain the required batteries 
at any authorized Mercedes-Benz 
Center. 
     
        
        Page 105 of 304

105 Controls in detail
Climate control
Air recirculation mode
Switch to air recirculation mode to prevent 
unpleasant odors from entering the vehicle 
from the outside. This setting cuts off the 
intake of outside air and recirculates the 
air in the passenger compartment.
Activating
Press button
Ð
 (page 102).
The indicator lamp on the
Ð
 button 
comes on.Deactivating
Press button
Ð
 (page 102).
The indicator lamp on the
Ð
 button 
goes out.
The air recirculation mode is deactivated 
automatically:
after five minutes if the outside temper-
ature is below approximately 41°F 
(5 °C)
after five minutes if the air conditioning 
is turned off
after 30 minutes if the outside temper-
ature is above approximately 41°F 
(5 °C)
At outside temperatures above 79°F 
(26 °C), the system will not automatically 
switch back to outside air. A quantity of 
outside air is added after approximately 
30 minutes.
Rear window defroster
The rear window defroster uses a large 
amount of power. To keep the battery 
drain to a minimum, switch off the defrost-
er as soon as the rear window is clear. The 
defroster is automatically deactivated af-
ter a maximum of 12 minutes.
Activating
Switch on the ignition.
Press button
F
 (page 102).
The indicator lamp on the button lights 
up.
Deactivating
Press button
F
 (page 102) again.
The indicator lamp on the button goes 
out.
Warning!
G
When the outside temperature is below 
41°F (5°C), only switch to air recirculation 
mode for short periods to prevent window 
fogging.iThe air recirculation mode is activated 
automatically at high outside temper-
tures. 
     
        
        Page 106 of 304

106 Controls in detailClimate control
Air conditioning
The air conditioning is operational while 
the engine is running and cools the interior 
air to the temperature set by the operator.Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the climate 
control system. The air in the vehicle will 
then no longer be cooled or dehumidified. 
Press buttonAC
OFF
 (page 102).
The indicator lamp on the 
AC
OFF
button lights up.
Warning!
G
Any accumulation of snow and ice should be 
removed from the rear window before driv-
ing. Visibility could otherwise be impaired, 
endangering you and others.!If the rear window defroster switches 
off too soon and the indicator lamp 
starts blinking, this means that too 
many electrical consumers are operat-
ing simultaneously and there is insuffi-
cient voltage in the battery. The system 
responds automatically by deactivating 
the rear window defroster. 
As soon as the battery has sufficient 
voltage, the rear window defroster au-
tomatically turns itself back on.
iCondensation may drip out from under-
neath the vehicle. This is normal and 
not an indication of a malfunction.
Warning!
G
While driving, deactivate the air conditioning 
only temporarily to prevent window fogging. 
     
        
        Page 173 of 304
173 Operation
Engine compartment
You can check the engine oil level with 
the oil dipstick
Open the hood (
page 171).
Pull out oil dipstick1 (
page 175) and 
wipe the tip clean.
Reinsert the oil dipstick into the dip-
stick guide tube as far as it will go.
1Oil dipstick
Pull out the oil dipstick again after 
approximately 3 seconds.
The oil level is acceptable when it 
leaves a line between the upper and 
lower marks of the dipstick.
For adding oil (
page 175).
See “Practical hints” (
page 200) if the 
low engine oil level warning lamp in the in-
strument cluster lights up.You can check the engine oil level on the 
odometer display (SLK 320 and 
SLK 32 AMG only)
Turn the key in the steering lock to 
position2.
1Knob
Wait until the symbols
:
 and
I
 
appear in the odometer display indica-
tor.
iFill quantity between upper and lower 
dipstick marking level is approximately 
2.1 US qt (2.0 l).
 
     
        
        Page 174 of 304

174 OperationEngine compartment
Within 1 second press knob1 on the 
instrument cluster twice.
One of the following messages will sub-
sequently appear in the indicator:
OK
-1.0 Q
 (Canada:
 -1.0 L
)
-1.5 Q
 (Canada:
 -1.5 L
)
-2.0 Q
 (Canada:
 -2.0 L
)
For adding oil (
page 175).If there is excessive engine oil with the en-
gine at normal operating temperature, a 
signal sounds and the following message 
will blink in the odometer display:
HI
Have excess oil siphoned.
If theI
 symbol flashes in the odometer 
display field, a proper oil level check can-
not be performed.
Wait 5 minutes before repeating check 
procedure.
Perform the oil level check with the dip-
stick (
page 173) if it cannot be complet-
ed via the odometer display field. In this 
case we recommend that you that you 
have the system checked at a 
Mercedes-Benz Center.See “Practical hints” (
page 200) if the 
low engine oil level warning lamp in the in-
strument cluster lights up.
!If the message 
-2.0 Q
 
(Canada:
-2.0 L
) blinks and a signal 
sounds, add oil according to amount 
displayed.
iIf the
:
 and
I
 symbols are con-
tinuously illuminated after pressing the 
left knob on the instrument cluster 
twice, and if there is no change in the 
odometer display field or the low en-
gine oil level warning lamp comes on, a 
malfunction has occurred to the sys-
tem. 
Perform the engine oil level check with 
the dipstick (
page 173).
If no oil leaks are noted, drive to the 
nearest Mercedes-Benz Center to have 
the system checked. 
     
        
        Page 197 of 304
197 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
1
The red SRS indicator lamp lights 
up while driving.
There is a malfunction in the restraint sys-
tems. The airbags or emergency tensioning 
device (ETDs) could deploy unexpectedly or 
fail to activate in an accident.
Drive with added caution to the 
nearest authorized Mercedes-Benz 
Center.
Warning!
G
In the event a malfunction of the SRS is indi-
cated as outlined above, the SRS may not be 
operational. For your safety, we strongly 
recommend that you visit an authorized 
Mercedes-Benz Center immediately to have 
the system checked. Otherwise the SRS 
may not be activated when needed in an ac-
cident, which could result in serious or fatal 
injury, or it might deploy unexpectedly and 
unnecessarily which could also result in an 
accident and/or injury to you or to others. 
     
        
        Page 198 of 304

198 Practical hintsWhat to do if …?Problem
Possible cause
Suggested solution
3
(Canada only)
;
(except Canada)The red brake warning lamp 
lights up while driving and you 
hear a warning sound.
You are driving with the parking brake set.
Release the parking brake 
(page 42).
3
(Canada only)
;
(except Canada)The red brake warning lamp 
lights up while driving.
There is insufficient brake fluid in the reser-
voir.
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. Don’t 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 200 of 304

200 Practical hintsWhat to do if …?When the low engine oil level warning lamp 
does not go out after starting the engine, 
or comes on while the engine is running 
and at operating temperature, the engine 
oil level has dropped to approximately the 
minimum mark on the dipstick.When this occurs, the warning lamp will 
first come on intermittently and then stay 
on if the oil level drops further.
If no oil leaks are noted, continue to drive 
to the nearest service station where the 
engine oil should be topped to the “full” 
mark on the dipstick with an approved oil.Problem
Possible cause
Suggested solution
_
The red telescoping steering 
column* warning lamp remains 
lit after starting the engine.
The adjustable steering column is not locked 
properly.
Lock the steering column 
(page 34).
W
The yellow low windshield and 
headlamp* washer system fluid 
level warning lamp remains lit af-
ter starting the engine or lights 
up while driving.
The fluid level has dropped to about
1/3 of 
total reservoir capacity.
Add washer fluid (
page 179).
N
The yellow low engine oil level 
warning lamp remains lit after 
starting the engine or lights up 
while driving.
The engine oil level is too low.
Check the engine oil level 
(page 172) and add oil as required 
(page 175).
If you must add engine oil frequently, 
have the engine checked for possible 
leaks.!The low engine oil level warning light 
should not be ignored. Extended driv-
ing with the light illuminated could re-
sult in serious engine damage that is 
not covered by the Mercedes-Benz 
Limited Warranty.