What was found
ETOPS SIGNIFICANT SYS - FRM 28412501 LT FUEL TANK & TOTAL FUEL QTY INDICATORS INTERMITTENT. EICAS MSG FUEL QTY IND DISPLAYED. FUEL QTY TEST NOT CHECKED. ACCOMP FQIS CAPACITANCE TEST IAW AMM28-41-00. OPS CK OK. ACCOMP LT MAIN TANK INSULATION RESISTANCE TEST IAW AMM28-41-00 & FOUND TANK UNIT NR 5 CAUSING ERRONEOUS HIZ TO SHIELD & SHIELD TO GROUND VALVE. REPLACED NR 5 TANK UNIT IAW AMM28-41-01. FUEL QTY BITE CK PEND. FUEL QTY BITE SHOWN NO FAULT CODE NOTE IAW AMM28-41-00.