What was found
AFTER LANDING, COULDN'T START THE APU. APU FAULT LIGHT SHOWN. FLT CREW NOTIFIED MX THAT APU WOULD NOT START, 2 ATTEMPTS. BIT ECU IAW 49-11-00, LAST 2 CYCLES "SEE MAINT MAN" AFTER AUTO SHUTDOWN. FOUND APU OIL LOW AND SERVICED IAW AMM 12-13-04, APU START SUCCESSFUL ON 3RD ATTEMPT. NO DEFECTS NOTED ON SUCCESSFUL RUN. ECU SELF TEST GOOD, MINI FLAG #15 ON LAMP CHECK. INFO ONLY: ECU LOCATED IN AFT CARGO AREA, MOISTURE NOTED. OPERATIONAL CHECK GOOD AT THIS TIME.