What was found
THE CREW REPORTED THAT THE APU STARTED IN FLIGHT WITH APPROXIMATELY THREE SECONDS OF APU FIRE MESSAGE, AND FUEL SMELL IN CABIN WHEN ON GROUND AND SWITCHING PACKS TO APU. THE AIRCRAFT LANDED WITH NO INCIDENT. MAINTENANCE INSPECTED THE AIRCRAFT AND PLACED THE APU ON MEL 49-00-00 CONTROL NUMBER 046935, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE. THE AIRCRAFT RETURNED ON 10/10/04 WHERE MAINTENANCE REMOVED AND REPLACED THE APU FUEL PRESSURE SWITCH, CLEANED THE APU FIRE LOOP CONNECTOR PLUG AND OPERATIONAL CHECKED WITH NO DEFECTS. THE APU WAS REMOVED FROM MEL AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.