As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH CENTER TANK FUEL QUANTITY AT 200 LBS, CTR FUEL PUMPS WERE TURNED ON AT CRUISE. BOTH CTR FUEL PUMP LIGHTS IMMEDIATELY ILLUMINATED AND REMAINED ON WITH NO APPARENT DECREASE IN CENTER FUEL QUANTITY. ONCE FUEL QUANTITY DECREASED BELOW 4500 LBS IN NUMBER 1 TANK, CENTER TANK QUANTITY LOWERED TO 0. GROUNDED - YES. CENTER TANK FUEL PUMP LOW PRESS LTS FUNCTION NORMAL PER B737-800 FIM 28-22 TASK 801. NO DISCREPANCY NOTED.