Hello guys! Hope someone can help me. 2007 Benz C280 w203 4 matic. Fuel gauge does not read fuel level properly. I can fill the tank and drive almost 300 miles and gauge just barely drops below full tank level. I have actually ran out of gas twice. Took it to local Euro shop they said it was a sender unit problem so they replaced BOTH sender unit/pumps with parts from Mercedes dealer. Called me and said all fixed. I filled the tank and needle went to full. Fast forward gauge does not drop and I ran out of gas again believing it was fixed. Nope. They hooked up computer and gauge has full swing when tested, so not a cluster motor problem. Then tried disconnecting battery, put the two cables together to drain all electronics and let sit that way 4 hours to reboot computers. Re-hooked up battery, needle went back up to full and drove it again. Again 280 miles in the needle still just below full. Anyone ever come across this problem? I'm wondering if it could be a SAM problem? I'm $900 into this now and just do not want to keep throwing parts at it. Not sure if there even was a problem with my sender units. Wondering if the dealer may be able to diagnose with star computer? Every time I cannot figure out a problem, it seems they cant either. LOL. Any help greatly appreciated and thank you!

 

Did you find the issue?
When they tested the gauge, did they use the new sender unit as part of the test? Could it be a faulty new sender unit?..