hi, my fuel gauge suddenly stop working (the niddle always in empty and the light is always on even though the tank is full)...do you have any idea what is the problem?thanks

 

Hello buddy,

It just so happens that I spoke with my mechanic today about this very issue.

In my case when I go to fill up my needle shows empty and "sometimes" the orange light is also burning. After I drive about 40-50 miles the needle goes back up to the full position provided I restart my 1999 ML-320.

The explanation I was given was that the gauge has internal contacts and because more and more ethanol is being added to fuel this in combination with H2O vapor is causing a build up between the contacts and a circuit isn't completed until such time the level of fuel has lowered in the tank.

This isn't a problem that you need to worry about or lose sleep over. However, I was told that this is a pain in the @#$ to replace as the back seat, carpet etc... needs to be taken out.

In my case, I don't care if I need to drive 50 miles to see the needle work again. This just isn't a big deal to me.

 

Latest on 2001 ML fuel gauge reading Mercedes has a bulletin to remove #5 fuse to let the computer remonitor fuel level and readjust to it.
I have the same problem on my 99 ML320 but I got used to it by now. Here I have found the bulletin:
DTB May 13, 2002 order # T-B-54.30/64 group 54
Subject: model 163.154/174/175 year 2001 and 2002
Fuel gauge accuracy
If you encounter instances in the above model vehicles where the fuel gauge reading is inaccurate, please perform the following procedure prior to replacing any components.
1. Remove fuse 5 in the RSE2 fuse holder
2. Reinstall fuse 5 into the RSE2 fuse holder.
3. Instruct the customers not ot fill the fuel tank untill they have reached the 1/2 tank level on the fuel gauge.

The fuel gauge reading for MY01 and MY02 vehicles have a virtual calculation performed on the first 19 liters (MY02) or 7 liters (MY01) of fuel. When the vehicle is filled prior to depleting the gas tank to these levels, an offset is calculated and stored in the instrument cluster memory. This is the cumulative affect and can result in the vehicle showing an empty tank even when actually full of fuel. The above procedure will remove any offset stored in the instrument cluster and return the fuel gauge to the correct accuracy.
This may help you out.

Search this forum for "fuel gauge".
You can check the sending unit easily by unpluging the fuel pump electric plug in the left rear wheel well and checking resistance between pin A-orange wire and pin B-gray wire.
Empty tank=200 ohm
Full tank=0.5 ohm
If on full tank you get reading of more then 3 ohms, your fuel level sending unit is bad, part No. A 163 470 01 94 This is tart of the fuel pump and not easy task to replace.
Good luck,
Bernard

 

How about me??? I got the same problem too but have the 1999 ML-320 and the info you posted does not match.

Would you like to assist me as well???

 

thanks Lentomies & mbenz80...we have the same problem...droved 70 miles and the fuel gauge go backs to normal...well..I will just leave the fuel gauge alone...have a great day!!!!!

 

Thanks for the info... and my question may be a real dumb question, but which fusebox do you mean when you say change FUSE#5? Is it the one near front passenger side or the one in the front engine compartment?

Thanks and I apologize for this dumb question....

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Thanks mbenz80, your solution of removing Fuse Ref F5 worked.

DocNyr... it is the fuse box located on the drivers side footwell side panel, just turn the two plastic round slots and the cover pops off.

There is a diagram attached to the inside of the plastic cover to show you which fuse is which.

Many thanks mbenz80