Hi, if the gauge is reading empty but there is fuel in the tank you may need to replace the fuel level sensor but I would try resetting the fuel gauge sensor circuit first. Sometimes the sensor logic gets fouled up and it reads incorrectly.
To reset the circuit you need to remove fuse #5 in the right front footwell fuse box for a few minutes and then reinsert it.
Give that a try and see if it works. If not you will probably need to replace the level sensor in the tank.
What does replacing a fuel level sensor cost?
I will check
The level sender on a 2000 ML is part of the fuel pump module. You would need to replace the complete module. The part runs $440 and labor should be in the 3 hour range.
Ok thank you.