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:
Controlling the front climate control
using the front control panel
Turn the SmartKey to position 2 in the
ignition lock.
Set the desired temperature.
To switch on: press the
rocker
switch up or down.
The indicator lamp in the rocker
switch lights up.
...
Muscular Moves
Shortly after last year's GL450 arrived, Mercedes introduced a diesel GL320
CDI; click here to compare the 2008 GL-Class with the 2007 model. Thanks to the
higher efficiency of its diesel engine, ...
Tire pressure monitor warning messages
If the tire pressure monitor detects a significant pressure loss on one or more
tires, a warning message is shown in the multifunction display. A warning tone also
sounds and the tire pressure war ...
