Page 285 of 464

285 Operation
At the gas station
Remove the SmartKey from the starter
switch.
Open fuel filler flap by pushing at point
indicated by arrow1.
The fuel filler flap springs open.
Turn fuel filler cap counterclockwise
and hold on to it until possible pressure
is released.
Take off fuel filler cap and set it in di-
rection of arrow2 in the recess on the
inside of fuel filler flap.
To prevent fuel vapors from escaping
into open air, fully insert filler nozzle
unit.
Only fill your tank until the filler nozzle
unit cuts out – do not top up or over-
fill.
Replace the fuel filler cap by turning it
clockwise until it engages audibly.
Close the fuel filler flap.
Check regularly and before a long tripEngine compartment (SLK 350, example)1Windshield washer system and head-
lamp cleaning system* reservoir
2Brake fluid reservoir
3Coolant expansion tank
Warning!
G
Overfilling of the fuel tank may create pres-
sure in the system which could cause a gas
discharge. This could cause the gas to spray
back out when removing the fuel pump noz-
zle, which could cause personal injury.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 in-
dicator lamp (Canada only) to illumi-
nate.
For more information, see “Practical
hints” (
page 344).
iFor opening the hood, see “Hood”
(page 287).
Page 344 of 464

344 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
?
±
(USA only)
(Canada only)
The yellow engine
malfunction indicator
lamp comes on while
driving.
There is a malfunction in:
the fuel management system
the ignition system
the emission control system
systems which affect emissions
Such malfunctions may result in ex-
cessive 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 system. It allows the accu-
rate identification of system malfunctions
through the readout of diagnostic trouble
codes. It is located in the front left area of the
footwell near the hood release.
Your fuel tank is empty.
After refueling start, turn off and restart the
engine three or four times in succession.
The limp-home mode is canceled. You do not
need to have your vehicle checked.
Additionally you see
the message
Check
gas cap
See Operator’s
Manual
in the multi-
function display.
A 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 leaking.
Check the fuel cap (
page 284).
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.
Page 394 of 464

394 Practical hintsFlat tire
PressI on electric air pump switch2.
The electric air pump switches on and
inflates the collapsible tire.
Inflate the collapsible tire to approxi-
mately 51 psi (3.5 bar).
This takes about five minutes for the
collapsible tire. Air hose4 and union
nut5 can become hot during infla-
tion. Exercise proper caution to avoid
burning yourself when using the equip-
ment.
Press0 on electric air pump switch2.
Turn the SmartKey in the starter switch
to position0.
The electric air pump should now be
switched off.
If the tire inflation pressure is above
51 psi (3.5 bar), release excess tire in-
flation pressure using the vent screw
on air hose4.
Detach the electric air pump.
Reinstall collapsible tire valve cap.
Store electrical plug3 and air
hose4 behind flap 1 and place the
electric air pump back in the trunk.
!Do not operate the electric air pump
longer than six minutes without inter-
ruption. Otherwise it may overheat.
You may operate the electric air pump
again after it has cooled off.
Warning!
G
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and / or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.