As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED DURING THE PREFLIGHT THE LT FUEL QUANITY INDICATOR SHOWED A RED X. TROUBLESHOOTING DISCOVERED THAT THE FCMU P/N 975.37.31.334 S/N 259 WAS DEFECTIVE. NOTE: FAULT CODES WERE INDICATING THAT THE LT INBOARD FUEL PROBE WAS AT FAULT. THE REPLACEMENT OF THE INBOARD FUEL PROBE AND WING WIRE HARNESS DID NOT CORRECT FAULT.