Opening the DEF filler cap
The filler neck for DEF is behind the fuel filler flap.
The fuel filler flap is unlocked or locked automatically when you open or close the vehicle with the SmartKey or with KEYLESSGO.

- Switch off the ignition.
- Press the fuel filler flap in the direction of
arrow 1.
The fuel filler flap swings up.
- Turn blue DEF filler cap 2
counterclockwise and remove it.
DEF filler cap 2 is secured with a plastic
strap.
See also:
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Problems with your vehicle
If you should experience a problem with your
vehicle, particularly one that you believe may
affect its safe operation, we urge you to
contact an authorized Mercedes-Benz Center
immediately to ...
