gafitanu

My tank level bar graph never shows the uppermost bar (which is actually like a half moon). I filled the tank all the way up to the cap but the last one never comes on. It's been bothering me for 10 years now. Is there a way through DAS to have the last bar to come on? Anybody knows?
Thank you.

S70Houston

Same here.

If it has been like this for 10 years, why worry about it now? You know the tank is full if it has been filled all the way to the top, what is the issue? As long as the gauge is not misrepresenting the fuel level while the tank is getting lower, who cares?

Drive more, worry less.

kjb55

the half moon isn't a bar indicating level.

NCTRNL

Kind of on this topic, I was told never to "top off" the tank for fear of soaking the charcoal filter so maybe you only get that top bar by really topping off the tank. I definitely notice it too.

Heatwave

I've never seen the half moon ... how do you know it's there?

Like others here, I never "pack" gas in our E350' gas tank. When the gas nozzle trip off, I give it one more squeeze just to make sure the nozzle didn't trip prematurely, but that's it ... no more gas. I've never seen a half moon and heretofore didn't know it existed.

gafitanu

The LCD bar graph has bars except the top and the bottom ones which look like a half moon (along the contour of the bar graph bezel). If you get down to the last bar, its shape is visible. It's not a problem or a defect it's more of an OCD thing (like the fridge light on when you close the door if you want). Somewhere in the software there must be a mapping between the fuel sender and the gauge and I was hoping someone bumped into this.
Kjb55, if it's not representing the level then what is it? The bottom half moon indicates about 0.8 gal. left which is consistent to any of the other bars for volume/bar.
I played so much with the settings on this car, SBC hold, removed belt warning, lock/unlock dutch beeps that I believe there must be a way.

Rob CL

When the key is in position 2, or just after starting the engine for keyless go folks, the LCD energizes all the cells in the gauge for a brief moment.

Rainers

The half moon has never meant to be used. It was the second question I Asked Mercedes when I bought the Car. I also verified back in 2007 when I bought my 2008 by looking at the other 12 new E350s in the lot

cetialpha5

Yeah, I think it's standard, I've never seen that half moon lit. All I ever see are bars. Never seen the half moon on the bottom, I guess I've never let it get that low.

cMazara

The so called bottom half moon is always on, no matter if it's full or half tank.
It's the last bar

kjb55

Attached a picture for reference. Consensus is it's not a defect rather a "just the way it is". The pic is from my W211 today, not a google image or other source.

rapidoxidation

The last bar that never lights represents the outage (free air space) that should always be present in a full tank of fuel. The Mercedes Engineers designed the gauge to not only represent the fuel level in the tank, but the air content as well. Given gasoline's thermal expansion rate of .069%/degree fahrenheit, a completely full tank of gasoline (no air at all) could potentially pop the tank if you filled up on a cold day and then it got warm.

20 gallon tank
50 degree difference
a bit over a half gallon volume increase.

kjb55

I've never paid so much attention to a fuel level gauge. For what it's worth - after filling up my W211 today and the picture i took ... the '0' is at the bottom of the half moon indicating it would include the half moon and the half moon being lit. The '1' (although not exactly clear in my picture because of the angle) is at the top of the last bar, but before the half moon indicating it would exclude the half moon and therefore it never being lit.

If only the balance shaft was this easy.

gafitanu

I tried but at start it still doesn't turn the top half moon on. With so many options available with DAS I was hoping this is somewhere in it too.
BTW a few years back I had a Kramer moment and the bottom half moon lasted 18 miles before the engine stalled.