279 Operation
At the gas station
At the gas station
Refueling
The fuel filler flap is located on the 
right-hand side of the vehicle towards the 
rear.Locking/unlocking the vehicle with the 
SmartKey or the SmartKey with 
KEYLESS-GO* automatically locks/un-
locks the fuel filler flap.
1Fuel filler flap
2Fuel filler cap
3HolderTurn off the engine
Vehicles with SmartKey: Remove the 
SmartKey from the starter switch.
Vehicles with KEYLESS-GO*: Open the 
driver’s door (this puts the starter 
switch in position 0, same as with the 
SmartKey removed from starter 
switch).
Open fuel filler flap 1 by pushing at 
the point indicated by the arrow.
The fuel filler flap springs open.
Turn fuel cap 2 counterclockwise and 
hold on to it until possible pressure is 
released.
Take off fuel cap 2 and place it into 
holder 3 located on the inside of the 
fuel filler flap.
Only fill your tank until the filler nozzle 
unit cuts out – do not top off or 
overfill.
Warning!G
Gasoline is highly flammable and poisonous. 
It burns violently and can cause serious 
personal injury.
Never allow sparks, flame or smoking mate-
rials near gasoline!
Turn off the engine before refueling.
Whenever you are around gasoline, avoid 
inhaling fumes and skin contact, extinguish 
all smoking materials.
Direct skin contact with fuels and the 
inhalation of fuel vapors are damaging your 
health.iIn case that the central locking system 
does not release the fuel filler flap, or the 
opening mechanism is clamping, notify Roadside 
Assistance or an authorized Mercedes-Benz 
Center.
 
303 Operation
Tires and wheels
Install the valve cap.
Repeat this procedure for each tire.Run Flat Indicator (Canada only)
While the vehicle is being driven, the Run 
Flat Indicator monitors the set tire inflation 
pressures by evaluating each wheel’s rota-
tional speed. This allows the system to de-
tect a significant loss of pressure in a tire. 
If a wheel’s rotational speed changes due 
to falling tire inflation pressure, you will 
see a corresponding warning message in 
the multifunction display.
The Run Flat Indicator may function in a re-
stricted manner or with a delay
if snow chains are mounted to the 
vehicle
in presence of ice and snow
if you are driving on a loose surface 
(e.g. sand or gravel)
if you are driving in a very sporty man-
ner (involving rapid acceleration or high 
speeds in curves)
iIf you have overfilled the tire, release tire in-
flation pressure by pushing the metal stem of the 
valve with e.g. a tip of a pen. Then recheck the 
tire inflation pressure with the tire gauge.Warning!G
When the multifunction display shows the 
message 
Tire Pressure Check Tires, 
one or more of your tires is significantly un-
derinflated. You should stop and check your 
tires as soon as possible, and inflate them to 
the proper tire inflation pressure as indicat-
ed on the vehicle’s Tire and Loading 
Information placard or, if available, on the 
tire inflation pressure label. Driving on a sig-
nificantly under-inflated tire causes the tire 
to overheat and can lead to tire failure. Un-
derinflation also reduces fuel efficiency and 
tire tread life, and may affect the vehicle’s 
handling and stopping ability. Each tire, in-
cluding the spare, should be checked 
monthly when cold and set to the recom-
mended tire inflation pressure as specified 
on the Tire and Loading Information placard 
on the driver’s door B-pillar (
page 295) or, 
if available, on the tire inflation pressure la-
bel located on the inside of the fuel filler flap 
(
page 279).