What was found
APU REPORTS SHOW A RAPID RISE IN CT5ATP TEMP AND HAS SURPASSED THE 605 DEGREE THRESHOLD. (#PRI1/ETOPS) CONTACT ETOPS MAINTENANCE CONTROL AND REPORT THAT THIS TASK HAS AFFECTED APU IN-FLIGHT START CAPABILITY, MEL 49-99A IS REQUIRED BEFORE FLIGHT. GROUNDED - YES. PERFORMED FIM 49-40 TASK 825 STEP D7 & D8, INSPECTED P1 WIRE HARNESS WITH NO DEFECT & EGT TERMINALS ARE SECURED, AND BOTH EGT THERMAL COUPLE 1 & 2 RESISTANCE TEST GOOD WITHIN LIMITS, DUE TO HISTORY SHOWS MAINT MSG 49-61157 "ECU INTERNAL FAILURE", REPLACED NEW ECU AND PERFORMED INSTALLATION TEST GOOD AMM 49-61-12/401. PERFORMED APU BITE PER FIM 49-70 TASK 801. NO FAULTS FOUND. PER TECH SVC IT NO FAULTS FOUND CLEAR TSR. THIS CLOSES TSR.