[JDRSOCAL]

I have an 2002 ML-500. Recently the fuel guage is indicating the tank is empty along with the glowing amber light despite recently filling the tank. Does anyone have any tips? Is there a way to re-set this? It just started this last night!

Thanks for any help.

 

[Witek_M]

Drive it 20 miles and see if it starts reading normal. Cycle key off/on. If it does replace fuel pump/level sensor. Most likely there will be code P0460 set in ECM.

 

[zbordas]

Have you tried to reset the gauge?

http://www.benzworld.org/forums/w163-m-class/1416753-fuel-gauge-problem.html#post4239086

 

[Mike's ML]

Try running Techron Complete Fuel System Cleaner (formally known as Concentrate Plus) in a couple of tanks of fuel. May work, may not but a cheep easy fix if it does work. It worked for me. I used a little more than the recommended amount for a 20 gal tank.
Note: do not use the cheaper Techron Carburetor Cleaner)

Mike

 

[Witek_M]

Try running Techron Complete Fuel System Cleaner (formally known as Concentrate Plus) in a couple of tanks of fuel. May work, may not but a cheep easy fix if it does work. It worked for me. I used a little more than the recommended amount for a 20 gal tank.
Note: do not use the cheaper Techron Carburetor Cleaner)

Mike

Once damage is done due to high sulfur fuel content there is no way to fix this issue. Only latest part number from MB has gold plated resistor and sweeps.

I have been dealing with this for at least 10 years. From reserve light on it takes 17.3 gl. to fill up. If put in ~14.0 gl gauge goes to count hair from full. If I fill it up it goes full than falls to reserve.

 

[AV8R4AA]

My 1999 ML430 does this every time.
Tried all the elixirs and nothing has worked.
I reset the trip meter every fill up.
When I get close(ish) to 300 miles driven it's time to refill.

 

[43sqd]

Where are these OP's who disappear for days after posting?

 

[sbk1972]

I have this issue too. If I fill up the tank to when the pump clicks off then the gauge works correctly. However if I squeeze in a few more liters, it seems to take the fuel level sensor off the scale and then causes the fuel gauge issue. The gauge will have a mind of it's own, up / down, showing empty etc until some fuel has burnt and the tank empties a little.

You can reset the gauge by removing the fuse from under the footwell fuse box. Cant remember which one but now Im used to it.

Simon

 

[AussieBenzes]

Its the blue fuse (number 5 from memory) in the footwell fuse panel (top row). I have to do that sometimes on the diesel once it hits 1/2 tank.

 

[JDRSOCAL]

A quick pull-out of the Blue no. 5 fuse has solved my problem! Thank you!

 

[Witek_M]

A quick pull-out of the Blue no. 5 fuse has solved my problem! Thank you!

Until next fill up.

 

[thaiedwin]

Drive it 20 miles and see if it starts reading normal. Cycle key off/on. If it does replace fuel pump/level sensor. Most likely there will be code P0460 set in ECM.

I had the same issue as OP. Mine was a bad fuel sensor. Replaced the whole fuel assembly.

 

[dparkinson]

I have a 2001 ml320 with 150k km on it. Beginning a couple of years ago I had to pull fuse 5 after every fillup in order for the guage to display fuel level. As of a month ago, that fix quit working and the fuel guage was always showing on empty.

I replaced fuel pump unit last week with a new spectra unit (designed to meet or exceed OEM) and voila - I could read my fuel level again. My exuberance lasted until today when my wife advises that the guage is again showing on empty despite her having fueled the vehicle. I am back to pulling fuse 5 and scratching my head as to the root cause.

At this point, I can rule out the fuel sending unit as it is brand new. Anyone have any ideas as to the root cause, please chime in.

 

[Troglodyte]

I have a 2001 ml320 with 150k km on it. Beginning a couple of years ago I had to pull fuse 5 after every fillup in order for the guage to display fuel level. As of a month ago, that fix quit working and the fuel guage was always showing on empty.

I replaced fuel pump unit last week with a new spectra unit (designed to meet or exceed OEM) and voila - I could read my fuel level again. My exuberance lasted until today when my wife advises that the guage is again showing on empty despite her having fueled the vehicle. I am back to pulling fuse 5 and scratching my head as to the root cause.

At this point, I can rule out the fuel sending unit as it is brand new. Anyone have any ideas as to the root cause, please chime in.

We live with it. At every fill up ya reset the trip OD on the dash. By the time is is at 1/2 full it works (on ours anyway) parking on a steep headed uphill over night helps allot too. If you over 300 mi. Ya Need Gas

 

[Witek_M]

I have a 2001 ml320 with 150k km on it. Beginning a couple of years ago I had to pull fuse 5 after every fillup in order for the guage to display fuel level. As of a month ago, that fix quit working and the fuel guage was always showing on empty.

I replaced fuel pump unit last week with a new spectra unit (designed to meet or exceed OEM) and voila - I could read my fuel level again. My exuberance lasted until today when my wife advises that the guage is again showing on empty despite her having fueled the vehicle. I am back to pulling fuse 5 and scratching my head as to the root cause.

At this point, I can rule out the fuel sending unit as it is brand new. Anyone have any ideas as to the root cause, please chime in.

Remove it, put it on the bench and test it. Smooth resistance change all trough the range. No hiccups, no opens, no shorts.

 

[Noodles]

We just had this happen with the 2002 ML500. The fuse 5 trick solved it for now.
Hoping it is not a sender. My wife let it get frightfully low on fuel and I put close
to 21 gallons in it.
If it is the sender we are just going to live with for awhile and seeing as it holds so
much fuel than the other MLs we have probably just put around 15-16 gallons of
fuel in it when it gets to the 1/4 mark.

 

[Merzatt]

We just had this happen with the 2002 ML500. The fuse 5 trick solved it for now.
Hoping it is not a sender. My wife let it get frightfully low on fuel and I put close
to 21 gallons in it.
If it is the sender we are just going to live with for awhile and seeing as it holds so
much fuel than the other MLs we have probably just put around 15-16 gallons of
fuel in it when it gets to the 1/4 mark.

Delphi pump?

 

[Noodles]

I believe it is the original. I have not looked at the pump yet.

 

[vvrjrlaw]

Remove it, put it on the bench and test it. Smooth resistance change all trough the range. No hiccups, no opens, no shorts.

Witek I finally solved my gauge problem by changing the fuel pump. I had mounted a switch in the fuse box and would press it to reset the fuel system. When the fuel pump died and I put a new one in the gauge sensor was part of the pump that was replaced. No problem since pump change.