What was found
ON PUSH BACK, STARTING RIGHT ENGINE, APU FAULT CAUSING POWER LOSS. ECU BITE CHECK WAS ACCOMPLISHED WITH NO FAULTS FOUND. AIRCRAFT RELEASED. ABOUT 30 MINUTES AFTER DEPARTURE APU FAULTED, SINGLE ELECTRICAL SOURCE, AIRCRAFT RETURNED TO DEPARTURE STATION. ON INBOUND APU WAS RESTATED AND RAN FOR ABOUT 10 MINUTES AND FAULTED AGAIN. A ECU BITE TEST REPORTED FAULT CODE 16 (P2 SENSOR). P2 SENSOR REPLACED APU OPS CHECK GOOD. (M)