As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE - FL330- LEFT TANK AFT FUEL PUMP LOW PRESSURE LIGHT ILLUMINATED WITH TANK FULL AND ALL 6 FUEL PUMP SWITCHES SELECTED ON. GROUNDED - YES. REMOVED AND REPLACED LEFT TANK AFT FUEL PUMP IAW B737-800 AMM 28-22-41/401. OPS AND LEAK CHECK GOOD.