What was found
NR 2 ENGINE CONTROL LIGHT ILLUMINATED ON GROUND. ACFT GROUNDED. REF FIM 73-06, TASK 801, PERFORMED ELECTRONIC ENGINE CONTROL BITE TEST ON NR 2 ENGINE ELECTRONIC ENGINE CONTROL, BITE TEST PASSED. ENGINE CONTROL NORMAL. ACFT OK FOR SERVICE. ENGINEERING REQUEST, ACCOMPLISHED DEU BITE & ELECTRONIC ENGINE CONTROL BITE REF FIM 31-62, TASK 801 & 73-00, TASK 801. NR 1 DEU LOGGED 31-61033 DU-CU LOW BRIGHTNESS, 31-61036 DU-CL LOW BRIGHTNESS, 31-68861 NO CAPTAIN DATA, & 31-65050 ALTITUDE DISAGREE. NR 2 DEU LOGGED 31-61033 DU-CU LOW BRIGHTNESS, 31-61036, DU-CL LOW BRIGHTNESS, 31-68862 NO CAPTAIN DATA, 31-65050, ALTITUDE DISAGREE, 31-61012, DU-LIB FAIL, & 31-61011, DU-LOB FAIL. NR 2 ELECTRONIC ENGINE CONTROL LOGGED 75-10582, TBV DEMAND & POSITION SIGNALS DISAGREE. ACCOMPLISHED FIM 75-23, TASK 801. ELECTRONIC ENGINE CONTROL BITE CHECK NORMAL. ACCOMPLISHED ACTUATORS TEST 3 TIMES, NO DEFECTS NOTED. TBV TORQUE MOTOR RESISTANCE NOMINAL AT 16 OHMS. DISCONNECTED, INSPECTED & CLEANED DP0907, TBV, DP0909 & DP0505, ELECTRONIC ENGINE CONTROL AND DP 0501, HMU, NO DEFECTS NOTED. SOCKET, PIN RETENTION TEST NORMAL REF AMM 70-70-01 AND SSM 75-31-22. INSPECTED CONNECTORS ON PREVIOUSLY MENTIONED UNITS, NO DEFECTS NOTED. RANG WIRING BETWEEN DP0907 & DP0909, DP0505 & DP0501, NO DEFECTS NOTED. AFTER CONNECTOR CLEANING, ACCOMPLISHED ELECTRONIC ENGINE CONTROL BITE, ACTUATORS TEST AND IDLE ENGINE RUN. NO DEFECTS NOTED, ALL INDICATIONS NORMAL. TBV DEMAND & POSITION DIFFERENCE WAS ONLY 7 PERCENT.