Page 193 of 474

192 Controls in detail
Automatic climate control*
Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the automatic
climate control system. The air in the
vehicle will then no longer be cooled or
dehumidified.
Press buttonœ (page 184).
The indicator lamp on the button goes
out.
Activating
Moist air can fog up the windows. You
can dehumidify the air with the air
conditioning.
Press buttonœ (page 184).
The indicator lamp on the button
comes on.
Residual heat and ventilation
With the engine switched off, it is possible
to continue to heat or ventilate the interior
for up to 30 minutes. This feature makes
use of the residual heat produced by the
engine.Activating
Switch off the ignition (page 37).
Press buttonT (page 184).
The indicator lamp on the button
comes on. The display in the automatic
climate control panel remains switched
off.
Deactivating
Press buttonT (page 184) again.
The indicator lamp on the button goes
out.
iHow long the system will provide heating
depends on
the coolant temperature
the temperature set by the operator
The blower will run at speed setting1 regardless
of the air volume control setting.
iThe residual heat is automatically turned off:
when the ignition is switched on (page 37)
after about 30 minutes
if the battery voltage drops
Page 290 of 474

289 Operation
Driving instructions
Emission control
Certain engine systems serve to keep the
toxic components of the exhaust gases
within permissible limits required by law.
These systems, of course, will function
properly only when maintained strictly
according to factory specifications.
Any adjustments on the engine should
therefore only be carried out by qualified
Mercedes-Benz Center authorized techni-
cians.
Engine adjustments should not be altered
in any way. Moreover, the specified service
jobs must be carried out regularly accord-
ing to Mercedes-Benz servicing require-
ments. For details refer to the
Maintenance Booklet.Coolant temperature
Warning!G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause un-
consciousness and possible 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 overheated
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 hood. Stay away from
the engine if you see or hear steam com-
ing 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 291 of 474
290 Operation
Driving instructions
!Excessive coolant temperature triggers a
warning message in the multifunction display
(
page 374).
The engine should not be operated with a
coolant temperature above 248°F (120°C).
Doing so may cause serious engine damage
which is not covered by the Mercedes-Benz
Limited Warranty.
iDuring severe operating conditions, e.g.
stop-and-go city traffic, the coolant temperature
may rise close to 248°F (120°C).
Page 293 of 474

292 Operation
At the gas station
Close the fuel filler flap.
Check regularly and before a long trip
Engine compartment
(example illustration, SLK 350)
1Windshield washer system and head-
lamp cleaning system* reservoir
2Brake fluid reservoir
3Coolant expansion tankWindshield washer system and head-
lamp cleaning system*
For information on refilling the reservoir,
see “Windshield washer system and
headlamp cleaning system*”
(
page 301).
Brake fluid
For information on brake fluid, see “Fuels,
coolants, lubricants, etc.” (
page 451).
iMake sure to close the fuel filler flap before
locking your vehicle as the flap locking pin
prevents closing after you have locked the
vehicle.
iOnly use premium unleaded gasoline with a
minimum Posted Octane Rating of 91 (average
of 96 RON/86 MON).
Information on gasoline quality can normally be
found on the fuel pump. Please contact gas
station personnel in case labels on the pump
cannot be found.
For more information on gasoline, see “Premium
unleaded gasoline” (
page 454), refer to the
Factory Approved Service Products pamphlet
(USA only), or contact an authorized
Mercedes-Benz-Center.
iLeaving the engine running and the fuel cap
open can cause the yellow fuel tank reserve
warning lamp to flash and the?malfunction
indicator lamp (USA only) or the
±malfunction indicator lamp (Canada only)
to illuminate.
For more information, see “Practical hints”
(
page 351).
iFor opening the hood, see “Hood”
(
page 294).
!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. Notify an
authorized Mercedes-Benz Center immediately.
Do not add brake fluid as this will not solve the
problem.
For more information, see “Practical hints”
(
page 350).
Page 294 of 474
293 Operation
At the gas station
Coolant
For normal replenishing, use water
(potable water quality).
For more information on coolant, see
“Coolant level” (
page 300) and “Fuels,
coolants, lubricants, etc.” (
page 451).
Engine oil level
For information on engine oil, see “Engine
oil” (
page 296).Vehicle lighting
Check function and cleanliness.
For more information on vehicle lighting,
see “Replacing bulbs” (
page 400).
For information on switching on the exteri-
or lighting, see “Exterior lamp switch”
(
page 109).
Tire inflation pressure
For information on tire inflation pressure,
see “Important notes on tire inflation
pressure” (
page 313).
Page 295 of 474

294 Operation
Engine compartment
Hood
Opening
1Hood lock release lever
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.
This could cause the hood to come loose
and injure you and/or others.
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
You could be injured when the hood is open
– even when the engine is turned off.
Parts of the engine can become very hot. To
prevent burns, let the engine cool off com-
pletely before touching any components on
the vehicle. Comply with all relevant safety
precautions.
Warning!G
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for
approximately 30 seconds or may even
restart after the engine has been turned off.
Stay clear of fan blades.
Warning!G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components
(ignition 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
Page 298 of 474

297 Operation
Engine compartment
One of the following messages will
subsequently appear in the multifunc-
tion display:
Engine Oil Level
OK
Add 1.0 qt. (Canada: 1.0 liter)
to reach max. oil level.
Add 1.5 qts. (Canada:
1.5 liters)
to reach max. oil level.
Add 2.0 qts. (Canada:
2.0 liters)
to reach max. oil level.
If necessary, add engine oil.
For adding engine oil, see “Adding
engine oil” (
page 299).
For more information on engine oil, see
“Fuels, coolants, lubricants, etc.”
(
page 451).Other display messages
If the ignition is not switched on, the fol-
lowing message will appear:
Turn on ignition
to see engine oil level
.
Switch on the ignition (page 37).
If you see the message:
Observe
Waiting Time
If engine is at operating temperature,
wait 5 minutes before repeating check
procedure.
If engine is not at operating tempera-
ture yet, you must wait 30 minutes
before checking oil.If you see the message:
Cannot check engine oil level
with engine on.
Turn off the engine.
If the engine is at operating tempera-
ture, wait 5 minutes before checking
oil.
If the engine is not at operating
temperature yet, you must wait
30 minutes before checking oil.
iIf you want to interrupt the checking
procedure, press buttonk orj on the
multifunction steering wheel (
page 122).
iIf you want to interrupt the checking
procedure, press buttonk orj on the
multifunction steering wheel (
page 122).
Page 300 of 474

299 Operation
Engine compartment
Pull out oil dipstick1 again after
approximately 3 seconds to obtain
accurate reading.
The oil level is correct when it is be-
tween the lower (min) mark3 and
upper (max) mark2 of oil dipstick1.
If necessary, add engine oil.
For adding engine oil, see “Adding
engine oil” (
page 299).
For more information on engine oil, see
“Fuels, coolants, lubricants, etc.”
(
page 451).
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(
page 360).Adding engine oil
SLK 350 (example illustration)
1Filler cap
SLK 55 AMG
1Filler cap
iThe filling quantity between the upper and
lower marks on the oil dipstick is approximately
2.1 US qt. (2.0 l).
!Only use approved engine oils and oil filters
required for vehicles with Maintenance System.
For a listing of approved engine oils and oil
filters, refer to the Factory Approved Service
Products pamphlet (USA only) in your vehicle
literature portfolio, or contact an authorized
Mercedes-Benz Center.
Using engine oils and oil filters of specification
other than those expressly required for the
Maintenance System, or changing of oil and oil
filter at change intervals longer than those called
for by the Maintenance System will result in
engine or emission control system damage not
covered by the Mercedes-Benz Limited
Warranty.