Mercedes-Benz 2012 E-Class Sedan Operator's Manual page 166

Refueling
164
Problems with fuel and the fuel tank
Problem
Fuel is leaking from the
vehicle.
The fuel filler flap
cannot be opened.
Possible causes/consequences and M Solutions
G
Risk of explosion or fire
The fuel line or the fuel tank is defective.
X
Turn the SmartKey to position 0(
immediately and remove it.
X
Do not restart the engine under any circumstances.
X
Consult a qualified specialist workshop.
The fuel filler flap is not unlocked.
or
The SmartKey battery is discharged.
X
Unlock the vehicle using the mechanical key (
X
Open the trunk lid or the tailgate.
X
Manually unlock the fuel filler flap using the emergency release
( Y page 163).
I n f o r m a t i o n P r o v i d e d b y :
Y
page 145) in the ignition lock
Y page 77).