What was found
WHILE ACCOMPLISHING T/C 78273000, FOUND NR 1 ENGINE WITH FAULT 73-31441, DEU 2 DATA IS MISSING. FAULT TIME LENGTH NOT GIVEN (SHORT, LONG, OR ECONOMIC), ONLY ALTERNATE MODE LIGHT MESSAGE. ACFT GROUNDED. IAW FIM 73-24 TASK 815, EEC BITE PASSED WITH NO MAINT MESSAGES PER STEP F.(1)(B), W/NO MAINT MESSAGE, SUGGESTION IS TO REPLACE DEU 2. IAW L/P'S 11684720, 11684721, AND 11684722, ALL 4 OF THESE RECORDED FAULTS APPEAR TO BE RELATED AND OCCURRED ON THE LAST FAULT. EACH FAULT HAS ITS OWN ASSIGNED FIM TASK AND ALL 4 SHOW EEC M1818 AS POSSIBLE CAUSE. PERFORMED FAULT ISOLATION TEST REF B737-900 FIM 73-24 TASK 815 PASSES EEC TEST. DETERMINED TO BE INTERMITTENT FAULT. NO HISTORY. OK FOR SERVICE.