I woke up this morning and the fuel door on my ML350 (2014) was open. The fuel gage on the dash showed empty and the miles to empty showed zero. So I assumed that my gas had been stolen. After adding about 5 gallons and closing the fuel door the gas gage showed 3/4 full. What could have caused 1. the fuel door to open and 2. the gage to show empty?

 

moved to W166 forum...

 

Fuel comes from the right (passenger side), and it fills two tubs as you can see in the drawing.

If someone can put a hose down to the first tube, and suck out fuel, at maximum, you will have half tank (real fuel). Not sure on the W166, but on the W211 there are two floaters that combine (believe average) their signals and shown in the cluster. I will have expected the fuel gauge to show @1/4 tank if originally your tank wall 100%. That is why there are two units in the tank, one refills the other tub (or allows the other to suck it out), and one pumps to the engine (filter is one of them)

With an MB-specific scanner, you should be able to see the individual levels on the tubs (if there are two floaters).

 

Curious… what did the digital range read after filling? 0 still? Or did it match the gas gauge reading ?

 

after filling it showed 400 mile range. My real question is why was the door open in the first place. thanks

 

That is puzzling to me as well since the door is locked if the car is locked. Have you checked the door is locked when is supposed to? I have not checked mine if the key is closed by, i.e. keyless go will also free the fueling door?

 

Did someone syphon gas out of the car? If it was locked then the gas cap would be locked. That is the only thing I can think of.

 

thanks, I think someone opened the gas door to siphon gas and got scared and ran off leaving the door open. That seems like the only logical explanation.

thanks everyone for your interest.