As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUEL CAP ATTACH CHAIN BECAME DISCONNECTED FROM THE TAB ON THE FILLER NECK ALLOWING THE LOOSE END TO FALL INTO THE TANK STILL ATTACHED TO THE CAP. THE LOOSE END OF THE CHAIN WRAPPED AROUND THE FINE WIRE ON THE FUEL SENDING UNIT. THIS CAUSED THE WIRE TO BECOME DISLODGED WHICH OPENED THE ELECTRICAL CIRCUIT CAUSING AN "EMPTY" READING ON THE FUEL QUANTITY GAUGE AND THE "LOW FUEL ANNUNCIATOR" TO ILLUMINATE.