What was found
APU HAS PREVIOUS HISTORY OF OVERTEMP SHUTDOWN AND REPORT OF APU INOPERATIVE WITH NO FAULT FOUND. ACFT GROUNDED. STEP 1 OF TSR FOUND MAINT MSG 49-52284, 49-52219, 49-41250, 49-41253. FAULT HISTORY SHOW 49-41012, 49-41010, 49-31016, 49-11023, 49-11021. R & R MAIN AND AUXILIARY BATTERIES, INSTALLATION TEST GOOD REF AMM 24-31-11. REPLACED APU LUBE MODULE REF AMM 49-91-11. REPLACED APU FUEL CONTROL UNIT REF AMM 49-31-11. BOTH OPS & LEAK CHECK GOOD. APU BITE CHECK GOOD.