What was found
DIAGNOSTIC REPORT, NR 2 ENGINE TREND DATA SHOWS A SHIFT IN DELTA CRUISE AND TAKEOFF MARGIN INDICATIVE OF EGT INDICATION ERRORS. ACFT GROUNDED. DURING NR 2 ENG EGT RESISTANCE CHECKS IAW MM 77-22-01, FOUND HARNESS INSULATION RESISTANCE BAD. REPLACED HARNESS IAW MM 73-21-06. OPS TESTED IAW AMM 73-21-06-400-803-F00. ACCOMPLISHED ALL FADEC SYS TESTS IAW AMM TASK 73-21-00-700-802-F00. EEC TEST TASK 73-21-00-700-804-F00, IDENT/CONFIG TASK 73-21-00-700-808-F00, ACTUATORS TEST TASK 71-00-00-700-807-F00, EEC DISCRETES TEST TASK 73-21-00-700-809-F00. ALL OPS TEST NORMAL. GROUND VERIFICATION SUCCESSFUL.