What was found
FLIGHT 6445 AUS TO SLC CREW RECEIVED A MASTER WARNING OF AFT CARGO DOOR OPEN, ABORTED TAKEOFF AND RETURNED TO GATE. MAINTENANCE INSPECTED THE DOOR, DETERMINED DOOR SENSOR TO BE FAULTY. MEL THE DOOR INDICATION AND DEPARTED WITH NO FURTHER INCIDENT. NO PARTS HAVE BEEN CHANGED TO DATE. THE SENSOR HAS BEEN ADJUSTED AND CLEANED. ENGINEERING HAS GENERATED AN EI TO INSPECT THE WIRE HARNESS AND REPLACE THE DOOR PROX SENSOR.