I have a 2012 C300 Sport and today it decided to not start. I have followed the failure back to the fuel pump where I get 12V when there is no load (pump not plugged in) but 0V when the load is present (pump plugged in). I removed the pump and plugged it into a variable DC power supply and was able to verify the pump works and pulls ~3A @ 12V. I am not sure where the issue lies since the pump works and I am getting 12V at the connector when no load but cant drive the pump. I have checked every fuse and I cant seem to find a fuel pump relay in any of the fuse diagrams I have found. Any help here would be greatly appreciated.