Hi everyone I am a new MB owner I purchased my 1998 ML320 YESTERDAY and i am already expirencing my first issue. I have read other forums and I now now that the fuel sending unit is often faulty in these cars. I also noticed that almost everyone who said they took it to the dealership to deal with this issue said that the dealership "reset" it for them and it worked fine until the next fill up. So my question is does anyone know how to reset it?


thanks

 

It will not help, I have try it few times already with no change or just for very short time.
Unless this procedure is wrong, you can try it, it's harmless for the car.
1. Wait till you fuel gauge is showing exact 1/2 of the tank.
2. Disconnect fuel pump plug located behind left rear wheel (front part of the wheel arch)
3. Turn on the ignition to position two (all dash lights on) gauge will stay at zero/empty
4. Plug the fuel pump connectors back together
Your sending unit should be reset.
When I fill up, my gauge is showing 3/4 to 7/8 full, never worked right and I got somehow osed to it after two years.
Three days ago, I just seen ML cut in half side to side through the gas tank, fuel pump and sending unit still in it. Contacts of the sending unit potentiometer are fully exposed inside the fuel tank and constantlly being splashed with gas.
I'm just waiting to have fuel pump problem to also take care of the incorrect fuel gauge level.

 

Thanks for the reply.... I tried pulling the fuses for the fuel pump and instrument cluster to try to reset it but it didnt seem to work I imagine that pulling the fuse for the pump would be the same as disconnecting it? Anyways the gauge reset itself after i took the car for a ride and it is now showing full. The next time it happens ill try your method. In the mean time ill just use the trip computer to track my mileage (so annoying)

 

I was searching the boards and was wondering if this is the correct part for a 1999 ML 430 Fuel guage sending unit.

#163-542-0518-OE - OB2 sending unit????

 

All fuel related parts are numbered in 470 group, correct part No. for your fuel level sending unit would be: A 163 470 01 94 and should be replaced FREE of charge up to ML serial No. A053980, acording to Aldata files.
I don't know why only up to this number, because my ML has a same exact problem with serial No. A07XXXX
On full tank, gray and orange wire should read less then 3 ohms other wise fuel sending unit resistor card needs calibration.

Marshman,
A1635420518 is fuel pressure sensor installed on fuel filler neck and should have no effect on your fuel gauge.

 

I had the same problem in my 2000 ML55 with fuel gauge not reading correctly.
When I actually filled up the tank, it was 1/4 full, and after filling up, it was reading 0.
The, after 50 miles or so, it came back to full.
I already replaced the fuel sending unit once.
This started to happen after 2 years since I replaced this unit and I had not driven
my ML55 for like a month
Is there is an updated part for this unit?
I have the tools to do the job but this is ridiculous.
I only fill with Chevron Super every time.
Any suggestions would be appreciated.
Thanks
Barry

 

first that pic is the fuel tank pressure differential sensor. the fuel level sender unit is located in the fuel tank under the rear seat and under the floor carpet. second replace the fuel level sensor/pump assmebly. how ever you will continue to have this problem for the rest of the cars life sorry.

 

no that pic is the pressure differential sensor

 

On my 2001 MBZ ML430, my gas tank was full to the brim, but gas gauge showed only 3/4 full tank. After driving about 3 miles I parked car and turn off ignition switch to turn off engine. I restarted car and gas gauge showed Empty Tank. The yellow gas warning light blinked.


I disconnect the battery cable off the Red Positive battery post (+). I then changed 2 15amp fuses on F11 and F19 that were related to gas fuel system, oxygen sensor, fuel injectors and reconnected battery cable. Both Blue 15AMP fuses looked good, but I replaced them.


When I restarted car, Gas Gauge showed a full tank of gas on dash instrument display panel.


I had to reset my 5 radio Code Number back into the radio system to program to activate my radio audio system. The Code is in your MBZ Operators Manual, or call Mercedes and provide them with VIN and they will provide you with radio code to reprogram your radio.