I have heard many complaints about the fuel gauge on the ML. Mine goes to empty when I fill it and until it has sat a few times after fill-up it finally (usually though not always) reads properly. I have unplugged the connector underneath a couple times and it reset it but this is obviously not the thing I want to do every 300 miles. I have resorted to just filling it up and resetting the trip meter then assuring my wife that if it reads low to check the trip mileage. Is there any fix that someone has done? This is honestly the only complaint I have about the vehicle and I can actually live with it, the wife freaks out the twice a month she drives it. It just seems really weird that MB can make so many cars for so many years and not be able to have something this basic work properly.

Thanks:

Steve

I have the same problem but changing the fuel sending unit is your only hope

Replace your fuel pump and filter at the same time. they are a pita to do. These pics should give you an idea, and no I didn't take all the pics on the same vehicle, nor are they of a ML55, I didn't take anypics of my own when I did it a couple months ago at T-giving. This require time, muscle and special tools.
Pay attention to the fuel filter, if yours is short, you will need the updated lines, if it has the new one show, you won't need the lines, but it would be a good idea to change it now.
Note: the short filter needs to be replaced asap, if yours still has it, it's just a matter of time until your fuel pump quits and leaves you stranded. I replaced mine in 2003!