What was found
NR 1 ENGINE SHOWS A FAULT 77-11131. THE N1 SPEED SENSOR SIGNALS DISAGREE, FOR LAST 3 FLT LEGS IN EEC MEMORY. FAULT 77-11131 IS A SHORT TERM FAULT. ACFT GROUNDED. ACCOMPLISHED FIM TASK 77-11, TASK 803 FOR FAULT CODE 77-11131 "N2 SENSOR SIGNAL DISAGREE". EEC FAULT HISTORY SHOWED BOTH 77-11131 "N2 SIGNALS DISAGREE" AND FAULT CODE 77-11181 "N2 SIGNAL IS OUT OF RANGE". IAW FIM TASK 77-11, TASK 803, IF FAULT CODE 77-11181 SHOWS IN RECENT FAULTS, ACCOMPLISH FIM TASK 77-11, TASK 802. FOUND N2 READINGS AT 59.9 OHMS, WITHIN LIMITS. REQUIRES NR 1 ENG EEC. EEC R & R REF AMM 73-21-60-000-801-F00, 73-21-60-400-801-F00. ALL TEST GOOD, IAW MM 73-21-00 FADEC TEST.