As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT MAIN FUEL TANK AFT PUMP LOW PRESSURE LIGHT ILLUMINATED, QRH COMPLETED - PUMP OFF. NO OTHER INDICATIONS. GROUNDED - YES. REMOVED AND REPLACED #1 AFT FUEL BOOST PUMP REF B737-900 AMM 28-22-41-000-801 AND 28-22-41-400-801. ACCOMPLISHED FUEL BOOST PUMP OPERATIONAL TEST ON # 1 AFT PUMP OP'S CK LEAK CK GOOD. GROUND VERIFICATION CHECK'S GOOD REF AMM 28-22-41-710-801.