You could try to access the sensor mechanism in the tank (attached to the pump). This is under the place where you checked the plug. The sensor is just a float on a wire, and it maybe possible that it is stuck in the empty position and you could maybe just jiggle it free. Be careful taking the pump out as it is a fiddly job, and the connectors where the pipes connect to the plastic lid can get brittle and break.


RealOEM.com * BMW E53 X5 4.6is Fuel pump and fuel level sensor